Jess Meyers
Member
Any one ready to try Chevrolet V-6's
Van's Air Force
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- Thread starter Jess Meyers
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gmcjetpilot
Well Known Member
Belted power
You know about "Belted Power"? They have stuffed many a V-6 into RV's. Check their site. GJess Meyers said:
Rotary10-RV
Well Known Member
Just so everybody knows, Mr Meyers IS, Belted Air Power. The setup is nice although the radiator system is marginal for higher power apps IMHO. Jess are you running lube oil in the bearings now or are they sealed units? I like the B.A.P. setup, the offset of the sprocket or pulley allows the V engine to have a normal thrust line and still fit the cowl. I am worried about the ducting to the radiator, (or lack of it). The cooling can be improved and the cooling drag reduced be carefully ducting a smaller radiator or two smaller radiators placed lower in the cowl.
Bill Jepson
Bill Jepson
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Jess Meyers
Member
chevy
Mr. Jepson, your correct we only need ONE radiator. The system was designed by Dr.M.C.Harrold formerly of Lockheed and cooling was one of his specialities. The upper area of the engine is baffeled off to provide a high pressure above the engine, this applies a slight boost to the carb, keeps the distributor in cool air as the belt is also cooled, the air is then drawn out of the cowl in a low pressure area resulting in good cooling. I know at our field the past few weeks the temp is over 105F. today it's in the 100 degree range a real cold snap and the engine only runs thermostat temp of 190 and the radiator 175. We will be back after the 22nd of this mo. and if you want to fly in it please come out to Vegas, and we will be happy to take you flying and you may witness this phenomenon for yourself. Bring your own gps as results may vary.
Mr. Jepson, your correct we only need ONE radiator. The system was designed by Dr.M.C.Harrold formerly of Lockheed and cooling was one of his specialities. The upper area of the engine is baffeled off to provide a high pressure above the engine, this applies a slight boost to the carb, keeps the distributor in cool air as the belt is also cooled, the air is then drawn out of the cowl in a low pressure area resulting in good cooling. I know at our field the past few weeks the temp is over 105F. today it's in the 100 degree range a real cold snap and the engine only runs thermostat temp of 190 and the radiator 175. We will be back after the 22nd of this mo. and if you want to fly in it please come out to Vegas, and we will be happy to take you flying and you may witness this phenomenon for yourself. Bring your own gps as results may vary.
gmcjetpilot
Well Known Member
I like it, and I don't like auto engines on planes
Kidding. Forget standard empty and gross weights. Jess is from belted (air) power. I get it rhetorical. (By the way google belted power works, so there )
If you want a "Sport Plane" with light handling you will be compromising it with any auto engine (Rotary being the least heavy). You'll definitely exceed all of Van's recommend weights (debate a way why that is OK). If you are building a cruiser, weight may not matter as much, at least from a handling standpoint.
I think their V6 set up performs fairly well, but none will win a race or set economy standards. No offense just from what I have read. Like most conversions, they are heavier, a little slower and burn a little more fuel (per mile). That's a compliment since many auto conversions are more than a little slower or thirsty.
With that said I really like "Belted Air Power's" approach. Simple, relying on a carb and points ignition and not over priced. Well done. I also like that large cog belt. Again, simple, reliable and harmonics are not an issue.
The harmonic advantage of the belt drive, plus the V6 power pulse, allows use of low priced experimental props, that can't take the pounding of a direct drive Lycoming, so you don't need a $9,000 MT prop.
If you want to be different, it's cool and looks reliable. Clearly they have been working on it for a long time and have (good) history. I like that it's a mature complete KIT for a reasonable price. It has no electronics or EFI to ruin your day. I don't know why they are not more popular. If I was told I had to use an auto engine in my plane (because that is the only way I would use one, no offense just a Lycoming man), this would be on top of my list.
If you have to ask how much it weighs you may not want the answer.djvdb63 said:
Kidding. Forget standard empty and gross weights. Jess is from belted (air) power. I get it rhetorical. (By the way google belted power works, so there )If you want a "Sport Plane" with light handling you will be compromising it with any auto engine (Rotary being the least heavy). You'll definitely exceed all of Van's recommend weights (debate a way why that is OK). If you are building a cruiser, weight may not matter as much, at least from a handling standpoint.
I think their V6 set up performs fairly well, but none will win a race or set economy standards. No offense just from what I have read. Like most conversions, they are heavier, a little slower and burn a little more fuel (per mile). That's a compliment since many auto conversions are more than a little slower or thirsty.
With that said I really like "Belted Air Power's" approach. Simple, relying on a carb and points ignition and not over priced. Well done. I also like that large cog belt. Again, simple, reliable and harmonics are not an issue.
The harmonic advantage of the belt drive, plus the V6 power pulse, allows use of low priced experimental props, that can't take the pounding of a direct drive Lycoming, so you don't need a $9,000 MT prop.
If you want to be different, it's cool and looks reliable. Clearly they have been working on it for a long time and have (good) history. I like that it's a mature complete KIT for a reasonable price. It has no electronics or EFI to ruin your day. I don't know why they are not more popular. If I was told I had to use an auto engine in my plane (because that is the only way I would use one, no offense just a Lycoming man), this would be on top of my list.
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Experience
If you are interested in using an auto engine in an airplane, do some research on Jess. You will find out that he has been flying auto engines longer than anyone else. The RV is not his first auto engine in one of his airplanes. Look up some of the old back issues of Sport Aviation and read about his Swift. He has been flying auto engines almost as long (if not longer) as I have been flying. (I got my license on my 25th birthday and turned 49 this year.)
If you are interested in using an auto engine in an airplane, do some research on Jess. You will find out that he has been flying auto engines longer than anyone else. The RV is not his first auto engine in one of his airplanes. Look up some of the old back issues of Sport Aviation and read about his Swift. He has been flying auto engines almost as long (if not longer) as I have been flying. (I got my license on my 25th birthday and turned 49 this year.)
Belted Air
George...
FWIW...I know all about Mr Meyers. I have read all the articles on Belted Air over the years...Sport Aviation, Kitplanes, Contact Magazine, Custom Planes, etc. etc. I find the setup attractive for many of the reasons that you mentioned. My tendency is to be attracted to something because of it's strengths...but then to decide on the thing based on whether I could live with the weaknesses.
Jan Egg seems unable to discuss the weaknesses of his packages in a straightforward way. This unnecessarily undermines his credibility, given that he has accomplished a great deal and there is much that he could honestly brag about.
So...since we have Jess Meyer's attention, I thought I would try to better understand what I suspect is the "achilles heel" of BAP...namely the weight of the package. That is why I asked about the empty weight of their RV-6A. I understand their airplane is fairly bare bones in terms of panel goodies and upholstery...at least is was described as such in some of the write-ups in the past. So understanding it's empty weight would help me to evaluate whether, in fact, the heaviness of the Vortec V-6 would be a deal killer for me.
George, the Egg Sub's could use a FP prop too, but it would compromise performance. I suspect this is true of BAP too, possibly to a lesser extent given the lower rpm ranges produced by the Vortec V-6 and the 1.41:1 PSRU ratio. In fact, the BAP web-site mentions a trial of a CS prop. There have been no updates on it for many moons, however.
There is a Mustang II with the BAP setup. Gale DeRosier around St. Louis. According the Gale, he cruises at 170 mph. This is probably 20 mph slower than an O-320 Mustang II...and 30 mph behind an O-360 Mustang II. And, Mr. Derosier says his setup weighs 40 lb. more than a 200 hp IO-360 would weigh. And this is with a very light FP prop. I suppose he would cruise faster if he added an electric CS prop. I also suppose he cannot afford to due to weight & CG issues.
Other than Gale's airplane, I have had difficulty finding performance reports from BAP customers. Maybe Jess could point me in the right directon
Dan
George...
FWIW...I know all about Mr Meyers. I have read all the articles on Belted Air over the years...Sport Aviation, Kitplanes, Contact Magazine, Custom Planes, etc. etc. I find the setup attractive for many of the reasons that you mentioned. My tendency is to be attracted to something because of it's strengths...but then to decide on the thing based on whether I could live with the weaknesses.
Jan Egg seems unable to discuss the weaknesses of his packages in a straightforward way. This unnecessarily undermines his credibility, given that he has accomplished a great deal and there is much that he could honestly brag about.
So...since we have Jess Meyer's attention, I thought I would try to better understand what I suspect is the "achilles heel" of BAP...namely the weight of the package. That is why I asked about the empty weight of their RV-6A. I understand their airplane is fairly bare bones in terms of panel goodies and upholstery...at least is was described as such in some of the write-ups in the past. So understanding it's empty weight would help me to evaluate whether, in fact, the heaviness of the Vortec V-6 would be a deal killer for me.
George, the Egg Sub's could use a FP prop too, but it would compromise performance. I suspect this is true of BAP too, possibly to a lesser extent given the lower rpm ranges produced by the Vortec V-6 and the 1.41:1 PSRU ratio. In fact, the BAP web-site mentions a trial of a CS prop. There have been no updates on it for many moons, however.
There is a Mustang II with the BAP setup. Gale DeRosier around St. Louis. According the Gale, he cruises at 170 mph. This is probably 20 mph slower than an O-320 Mustang II...and 30 mph behind an O-360 Mustang II. And, Mr. Derosier says his setup weighs 40 lb. more than a 200 hp IO-360 would weigh. And this is with a very light FP prop. I suppose he would cruise faster if he added an electric CS prop. I also suppose he cannot afford to due to weight & CG issues.
Other than Gale's airplane, I have had difficulty finding performance reports from BAP customers. Maybe Jess could point me in the right directon
Dan
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gmcjetpilot
Well Known Member
Good Dan
I did a quick search from the dead sea scrolls going back 7-8 years on another RV list and read these unconfirmed data:
I DON'T KNOW IF THIS IS STILL TRUE. Jess, sorry for the scuttlebutt. It's not a new concept. I knew of a RV guy with a custom Ford V6 and it was not bad but was on the slow side. He was trying to get more speed with cowl mods, because his first pass was not elegant. His advice or feeling was if you want to go flying get a Lycoming. You like time spent on the custom installation and tinkering the conversion is worth it. It was way more than bolting up a Lyc for sure. However the BAP kit would no doubt make the installation time shorter and closer or similar to a Lyc. The Ford guy was going it alone without a kit, and this was many years ago.
Dan nice write up. I agree weight is an issue, and have followed their work for a long time as well. For all you who want to read more they have articles on their web site. Look forward to Jess telling us more specifics about empty weight and performance. What would be great is a fly off side by side to a O320 RV. This was done with the Rotary and Eggenfellner RV's against Van's factory planes. That is the only way to do it. Jess interested in a fly off?djvdb63 said:
I did a quick search from the dead sea scrolls going back 7-8 years on another RV list and read these unconfirmed data:
-Initial cost is going to be cheaper
-Performance is like a heavy 150-160HP O320
-Some have used Buick and Ford V6 engines as well
-Chevy conversions are 100-150lbs heaver (also saw 160-200lbs) Guess at least 150 lbs
-Cost saving goes away (more than a Lyc) w/ weight savings (exotic Alum heads/block)
-Performance is like a heavy 150-160HP O320
-Some have used Buick and Ford V6 engines as well
-Chevy conversions are 100-150lbs heaver (also saw 160-200lbs) Guess at least 150 lbs
-Cost saving goes away (more than a Lyc) w/ weight savings (exotic Alum heads/block)
I DON'T KNOW IF THIS IS STILL TRUE. Jess, sorry for the scuttlebutt. It's not a new concept. I knew of a RV guy with a custom Ford V6 and it was not bad but was on the slow side. He was trying to get more speed with cowl mods, because his first pass was not elegant. His advice or feeling was if you want to go flying get a Lycoming. You like time spent on the custom installation and tinkering the conversion is worth it. It was way more than bolting up a Lyc for sure. However the BAP kit would no doubt make the installation time shorter and closer or similar to a Lyc. The Ford guy was going it alone without a kit, and this was many years ago.
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Jess Meyers
Member
chevy's
Yes our plane is 1135 down from 1150. We changed to two Odysey dry cells for redundancy, changed several items under the cowl down to now what we produce. It depends on the throttle setting for speeds and powers, but I can relate our fuel flow test, It was select left tank, start engine, get in line, takeoff, climb to 6500 fly to Dagget 150 st. miles circle the VOR and return at 7500 let down and land, fill the tank 14 U.S Gallons total run time 2:10 minutes. Fly several other flights determine at regular cruise 3500 23" 155 ind miles 7.5 gallons per hour. We cool with liquid not fuel. We are faster than some slower than others. Lighter than some heavier than others. Tom my flying partner only comes in at slightly below 150 lbs me I gross at 207 and wishing I could lose 10 lbs. As we say come out bring your gps or meet up with us at the western area flyins and we'll take you flying. Today was cool 97F we were 45 under gross and it still left the pattern showing 1000 fpm climb. So I hope that answers some questions as to the upholstery it's quite essential due to many people climbing in and out we elected not to go plush, and it's easier to clean if someone gets well you know, sometimes they don't clean up after themselves..
Yes our plane is 1135 down from 1150. We changed to two Odysey dry cells for redundancy, changed several items under the cowl down to now what we produce. It depends on the throttle setting for speeds and powers, but I can relate our fuel flow test, It was select left tank, start engine, get in line, takeoff, climb to 6500 fly to Dagget 150 st. miles circle the VOR and return at 7500 let down and land, fill the tank 14 U.S Gallons total run time 2:10 minutes. Fly several other flights determine at regular cruise 3500 23" 155 ind miles 7.5 gallons per hour. We cool with liquid not fuel. We are faster than some slower than others. Lighter than some heavier than others. Tom my flying partner only comes in at slightly below 150 lbs me I gross at 207 and wishing I could lose 10 lbs. As we say come out bring your gps or meet up with us at the western area flyins and we'll take you flying. Today was cool 97F we were 45 under gross and it still left the pattern showing 1000 fpm climb. So I hope that answers some questions as to the upholstery it's quite essential due to many people climbing in and out we elected not to go plush, and it's easier to clean if someone gets well you know, sometimes they don't clean up after themselves..
David-aviator
Well Known Member
djvdb63 said:
I've tried fixed pitch with the H4 and H6 Egg Subby. The performance compromise is too great for me. Either you roll on the runway like a heavy B-52, or the prop overspeeds shortly after take off. With the H4, I fixed the Quinti CS by using manual and with the H6 I ordered a very nice 3 blade wood prop from Fred Felix cut for a 0360 Lycoming, not knowing what to use as a reference for the auto engine. It was terribly under pitched and turned up only 3800 rpm (prop 2087) on take off. It was not a total loss as I sold the prop to a RV-4 friend who had just installed a 0360 and he loves it. With the 0360, it turns up about 2300 for take off.
I don't know anyone flying with fixed pitch with an auto engine except Gale Derosier and his is a ground adjustable warp drive. I flew loose formation with Gale the year he went to OSH with the Mustang II, maybe 4 or 5 years ago. We are hangar neighbors.
dd
txaviator
Well Known Member
Another Chevy thread....
Here's another thread where we also discussed this back 6-7 months ago.
Good reading, and some good research by George.
http://www.vansairforce.com/community/showthread.php?t=5249&highlight=chevy
Here's another thread where we also discussed this back 6-7 months ago.
Good reading, and some good research by George.
http://www.vansairforce.com/community/showthread.php?t=5249&highlight=chevy
Jess...
Thanks for your very straight-forward response to the weight question.
What would be the specific cost increase for aluminum heads? Aluminum block? What would be the weight savings of using either/both of these?
What is the latest on the electric CS prop you have mentioned on the web site? Are you still using it? How much does it weigh? If so, what performance improvements have been realized?
Have you considered testing any of the other electic CS prop's on the market...Quinti, MT, Ivo, etc? Or are they just too heavy?
Have there been any in-flight failures of the BAP setup 4.3L Vortec V6?
Thanks...
Dan
Thanks for your very straight-forward response to the weight question.
What would be the specific cost increase for aluminum heads? Aluminum block? What would be the weight savings of using either/both of these?
What is the latest on the electric CS prop you have mentioned on the web site? Are you still using it? How much does it weigh? If so, what performance improvements have been realized?
Have you considered testing any of the other electic CS prop's on the market...Quinti, MT, Ivo, etc? Or are they just too heavy?
Have there been any in-flight failures of the BAP setup 4.3L Vortec V6?
Thanks...
Dan
Jess Meyers
Member
chevy
Dan, thanks for the interest, The aluminum heads will net a 40 lb savings. But the price is $2000.00 just for the heads. The new prepreg cowl will save 15 lbs over ours that we currently are using. I could go on a diet and I think that will be the best. The prop came in at 25 lbs all up including the power pack that is mounted any where that's convient. It is a hydraulic prop that does not require a hollow or oil shaft. It is working great, as we said on the site it was in the preliminary stages. The company is making changes to the design of the internal hub so that it can be used on "thumpers" otherwise it would be only for reduction type units. We have not tried the other props due to cost and return customer input. The performance was astounding on the low end, we could turn the chevy as low as 2500 rpm for 125 ind. So before all the howling this translated into 3gph over 10 hours range. It still might be seen. It also let the plane exceed the 190s in level flight. Our airplane is a little draggy, as Tom says it was built in 90 days but looks like 30 and this was before quickbuild. Yes we had one failure it was ours It was a quick throw on and the bearings were misaligned, the belt broke at 9500 msl over the desert of AZ. we landed on a road, hitched a ride to town changed the belt saw Seilegman Day's first hand had a cowboy fire off a 44 to chase the cows off the road and departed for home. This was 9 years ago,. by the way the total windmilling prop like the old rubber models didn't impead the glide much at all.
Dan, thanks for the interest, The aluminum heads will net a 40 lb savings. But the price is $2000.00 just for the heads. The new prepreg cowl will save 15 lbs over ours that we currently are using. I could go on a diet and I think that will be the best. The prop came in at 25 lbs all up including the power pack that is mounted any where that's convient. It is a hydraulic prop that does not require a hollow or oil shaft. It is working great, as we said on the site it was in the preliminary stages. The company is making changes to the design of the internal hub so that it can be used on "thumpers" otherwise it would be only for reduction type units. We have not tried the other props due to cost and return customer input. The performance was astounding on the low end, we could turn the chevy as low as 2500 rpm for 125 ind. So before all the howling this translated into 3gph over 10 hours range. It still might be seen. It also let the plane exceed the 190s in level flight. Our airplane is a little draggy, as Tom says it was built in 90 days but looks like 30 and this was before quickbuild. Yes we had one failure it was ours It was a quick throw on and the bearings were misaligned, the belt broke at 9500 msl over the desert of AZ. we landed on a road, hitched a ride to town changed the belt saw Seilegman Day's first hand had a cowboy fire off a 44 to chase the cows off the road and departed for home. This was 9 years ago,. by the way the total windmilling prop like the old rubber models didn't impead the glide much at all.
gmcjetpilot
Well Known Member
More info needed please
What does an aluminum block cost and how much weight savings? Are they rare race only items?
What a Hydraulic prop that does not need a hollow shaft for reduction drive /engined planes?
Tell use more about the prop please? (cost, how it works, who makes it) I am fascinated it has a "power pack"? is that electrically powered or engine powered.
Jess, interesting.Jess Meyers said:
What does an aluminum block cost and how much weight savings? Are they rare race only items?
What a Hydraulic prop that does not need a hollow shaft for reduction drive /engined planes?
Tell use more about the prop please? (cost, how it works, who makes it) I am fascinated it has a "power pack"? is that electrically powered or engine powered.
Jess...
Are you saying a builder could save 40 lb. for $2000? That sounds like a reasonable trade-off. Or are there extra costs to machine the heads & prepare them for the airplane? Would the aluminum heads be durable? Reliable?
So...say the average BAP 4.3L package with Fixed Prop weighs 150 lb. more than a typical Lyc O-320. One could save 15 lb. with lighter batteries, 15 lb. with your newer cowling, 40 lb. with the aluminum heads. Total 70 lb. weight savings? That doesn't sound too bad.
I suppose one would give some of that back with your newer CS prop, if it becomes available. Your Warp Drive 3-blade prop weighs, what...12 lb. as I recall? So one would give back about 13 lb. if the CS prop you are trying weighs 25 lb. as you say.
Yes...do tell us more about this hydraulic CS prop you are talking about... When might it become available? Cost?
Thanks...
Dan
Are you saying a builder could save 40 lb. for $2000? That sounds like a reasonable trade-off. Or are there extra costs to machine the heads & prepare them for the airplane? Would the aluminum heads be durable? Reliable?
So...say the average BAP 4.3L package with Fixed Prop weighs 150 lb. more than a typical Lyc O-320. One could save 15 lb. with lighter batteries, 15 lb. with your newer cowling, 40 lb. with the aluminum heads. Total 70 lb. weight savings? That doesn't sound too bad.
I suppose one would give some of that back with your newer CS prop, if it becomes available. Your Warp Drive 3-blade prop weighs, what...12 lb. as I recall? So one would give back about 13 lb. if the CS prop you are trying weighs 25 lb. as you say.
Yes...do tell us more about this hydraulic CS prop you are talking about... When might it become available? Cost?
Thanks...
Dan
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Jess Meyers
Member
chevy
Dan, the prop people are very busy getting the package together, At present it might be 6 months or so. As more information is available they will make the word for all to see, we are trying to assure that it will be compatable with all engines. There is also a 4 seater from down under that will be using the chevy set up shortly, mild manners fixed gear 150 or so very reasonable all metal. We have been very busy and will be out of town for the next week and a half, will try to check in once in a while. Fly safe.
jess
Dan, the prop people are very busy getting the package together, At present it might be 6 months or so. As more information is available they will make the word for all to see, we are trying to assure that it will be compatable with all engines. There is also a 4 seater from down under that will be using the chevy set up shortly, mild manners fixed gear 150 or so very reasonable all metal. We have been very busy and will be out of town for the next week and a half, will try to check in once in a while. Fly safe.
jess
Brian Denk
Well Known Member
Ooooh you TEASE!!! Thanks for stopping by, Jess. I've only seen your engine installation on the web and while flying demos overhead at Copperstate a few years ago. I do recall the sound and apparent speed got my attention. Maybe it just sounded fast but I swear you were really hauling the freight that day....faster than any of Van's demonstrators seemed to be showing.
Nice to see you're progressing forward with a HYDRO prop. The prop issue on the automotive engine packages has always given me enough pause to not consider them at all. That might change.
Thanks for stopping by, Jess. I've only seen your engine installation on the web and while flying demos overhead at Copperstate a few years ago. I do recall the sound and apparent speed got my attention. Maybe it just sounded fast but I swear you were really hauling the freight that day....faster than any of Van's demonstrators seemed to be showing.Nice to see you're progressing forward with a HYDRO prop. The prop issue on the automotive engine packages has always given me enough pause to not consider them at all. That might change.
gmcjetpilot
Well Known Member
me to
Thanks also please, do you have any info? And more info on the hydraylic prop on solid crank/reduction drive. Thankscjensen said:
Guys, GM offers the engine block in a couple of aluminum versions. Basically they way about 90 pounds, and cost around $3200. If memory serves, that's a savings of about 70 pounds?? You might find a decent used one on the circle track circuits. There was a race series, I forget which, in the midwest that used them exclusively. I understand that series has been disolved...so there could be some buys out there. The GM aluminum heads require some weird stuff to make 'em work. Brodix however offers a set ($1800) that would be ideal. They use a lot of off the shelf components. The only problem, I think they advertise the peak RPM range is like 4000-7000. That's a little hot. Camshaft selection has a lot to do with this though, so long as port size isn't too far out of hand. I'm convinced it can weigh the same as a Lycoming (or reasonably close) and make more power than an O-360. BUT buy the time you make the mods, buy the aluminum stuff, get it tuned, etc, you could have as much in it as a typical mid time Lycoming costs, and take longer/have more teething problems. I'm a huge fan of this engine, but I'm no engineer...so I'll PROBABLY opt for the vanilla O-320 with FP prop. I figure for an aluminum block/head combo I'd have about $11,000-$12,000 in it including PSRU, mount, radiator, etc. So...why the hassle?
pierre smith
Well Known Member
You got it!!
That's it in a nutshell, Rampeyboy.
There are many aftermarket engine/prop combos and it's obviously the ones with the least amount of engineering the user has to do that sell, e.g. Eggenfellner with his FWF setup and now, Belted Air comes close too. In the long run, there is still a lot of extra sorting out to do and as you figured, no savings at the end.
Take your V-6 or Egg to the Bahamas and break down......who do you ask to fix it? Take your Lyc........seewhatamean?
My take on it all.......I wanted to fly quick and easy so I stuck with the known. Others want to tinker and that's O.K. too, what Experimental is all about.
That's it in a nutshell, Rampeyboy.
There are many aftermarket engine/prop combos and it's obviously the ones with the least amount of engineering the user has to do that sell, e.g. Eggenfellner with his FWF setup and now, Belted Air comes close too. In the long run, there is still a lot of extra sorting out to do and as you figured, no savings at the end.
Take your V-6 or Egg to the Bahamas and break down......who do you ask to fix it? Take your Lyc........seewhatamean?
My take on it all.......I wanted to fly quick and easy so I stuck with the known. Others want to tinker and that's O.K. too, what Experimental is all about.
gmcjetpilot
Well Known Member
Yippee, more, more
Here we go...
..... more more
Thanks Rampboy for the aluminum head / block explanation. Port size could be less than ideal, but should work with right cam, got it. I am not sure about the HP issue when run down in the needed RPM range for reduction/prop drive, but interesting. Like I said there simple Belt Drive, CARB, POINTS no electronics approach makes lots of sense to me, even as a die-hard Lycoming driver.
Here we go...
Thanks Rampboy for the aluminum head / block explanation. Port size could be less than ideal, but should work with right cam, got it. I am not sure about the HP issue when run down in the needed RPM range for reduction/prop drive, but interesting. Like I said there simple Belt Drive, CARB, POINTS no electronics approach makes lots of sense to me, even as a die-hard Lycoming driver.
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Jess Meyers
Member
Dan, were back, trying to answer some of the recent questions The all alloy version on an RV is too light, one of our customers had his battery 6" ahead of the firewall and wished for 12. Camming is the answer for the power band. As for the repairs, I understand the worries but Chevy's don't seem to have a problem. We elected to go as stock as possible ie. out of the box. In 25 years we have never broken a manifold or lost a starter. Alternators are another issue but reading the Lyc. guys it's universal. The Holley carb with the mixture block either works or you will never get it started, from the first run. The distributor is very reliable and we used it in leiu of Van's oil psi. set up when the oil went to 0 when topping out on a cloud deck. Since the dist drives the oil pump and the engine was running it did give some relief. Two senders and two gages later we went to Stewart Warner and no problems. You ask the biggest problem, actually there are two time and money. We try to go out when we can and with the time we have. Some of our customers problems relate to the engine builder trying to build a power house engine instead of just for the long haul, stock the engine has the RV related power with ample with a fixed pitch prop. We set ours to demonstrate a climb of 1000fpm on a 100 degree day and still show 170 plus at WOT. It can be pitched for more speed if that's your desire or more climb. Again bring your own GPS (Ours Lies) and fly with us. That's about all I can offer for those of doubt.
Jess, what about the L2? Need at least 250HP
I'm building a -10 and am interested in a GM engine - if it works that is . . .
What are your thoughts about an engine for the -10?
Jeff
[email protected]
I'm building a -10 and am interested in a GM engine - if it works that is . . .
What are your thoughts about an engine for the -10?
Jeff
[email protected]
gmcjetpilot
Well Known Member
Robinson
(Note: Of interest is click on the http://www.v8seabee.com/ and look at the video's. Warning turn volumn down since some are real loud, big sea plane prop at high RPM. I think that is the only one plane they really have going(?), the SeaBee conversion "looking for investors". I gather that is the origin of this company, putting the V8 into SeaBee's on an experimental basis. They list the RV-10 as one of the suitable kit planes but there is no "KIT" just the engnie and drive at this time. As far as price of their reduction drive? A lot? They do list a hydraulic prop gov pad but looking at picture gallery they use a SWASH plate PROP!
http://gallery.v8seabee.com/detail.asp?iType=34&iPic=237.
I think their drive will work with reg Hyd props as well. The reduction drive looks long, so the stock cowl will not work, but heard they are working on a shorter PSRU unit so the stock Lyc cowl can be used.
There is little info on installed weight and cost. Reading there FAQ and there "Operation Cost" I think they are exaggerating the overhaul cost of a Lyc 540 ($40,000) by a factor of over 2 to 2.5. Their fuel burn of 10 gal verses 15 gal per hour is suspect. I doubt that it has 33% better fuel efficiency, the real world and physics gets in the way of these outstanding spacific fuel burns.
My point is proceed with caution. At least with BeltedAirPower you have history and many flying in RV's. If they have a V8 conversion with there reliable philosophy, it would be a safer way to go. The Robinson PSRU with hyd prop gov pad looks good, but at how much weight and cost?)
I know little about Robinson but it may be worth a look. My comment would be a Lycoming as expensive as 540's might be, it will likely cost more and take way longer to build a V8. I don't think V8power has a FWF kit for the RV-10 but if they do, its not going to save you money. If you have to design as you go it will add many 100's of hours to the project. I don't know what your motive is for considering not following "The Plans" of using the recommend engine. If it's cost alone I would really look at going with a used 540 with a homebuilder overhaul with some pro guidance. It is not that hard. Going brand new 540 out the door is about $39,000. Believe it or not they may be cheaper. I can see you getting a core and building it for low mid $20k's. Than you can use the kit parts and all the knowledge and parts for the Lyc, if you goal is to have a plane to fly and not tinker with. Just my personal philosophy. Just not sure if you want to have an experimental auto engine installation that no one else has proven. The Subaru/Mazda/V6 in the two seater RV's has more track record. In the end you have to prepare yourself for the "experiment" not to work real well. There is always that risk.
If you want to go fly the Lyc is the way to go. If you enjoy and extra challenge and having something unique, even if it takes longer and cost the same or more, than the V8 may be the way to go. Keep in mind a Lyc 540 is not that heavy. A LS6 (big block) + PSRU + Radiator + Liquids is going to weigh a lot. You only need 260 HP. Also you will be going away from BeltedAirPowers philosophy which I think is 100% right on for an alternative engine. The Robinson from what I see is electronic and gear/chain. Also with no RV-10 kit yet, designed and proven as BeltedAirPower, you are a test pilot. Not a put down, just an opinion that as a pioneer you can expect a lot of development on your own time and lots of reworks.
After you start down the V8 power road, who knows about performance (and weight) as installed. If I was building a Rocket or -10 I would find a core 540 and tear it down and rebuild it myself. There is no way around expensive engines that make +250 HP with aircraft reliability and hyd prop control. Keep in mind the RV-10 is a hauler, 4 place plane. My concern is the V8 will weigh so much, taking a way from the payload and basically making a 4-place plane into a 2-place payload limited plane with 4 seats.
On this Forum a Rocket pilot posted some video of a flight. Listen to the Lyc 540 purr. The 540 is a awesome engine, consider building to plans, it will save you time and grief.
There is no free lunch folks. When some one says they have an engine that makes more power, burns less gas, cost way less and does not weigh much more than an air-cooled Lyc, my bogosity meter pegs. The V8power guys sound like real nice folks there up in Canada. Give them a call, it might be the ticket for some?
Not trying to steal Jess's thunder. He is the man for BeltedAirPower. However I have seen the ad for Robinson VB power in the EAA mag. http://www.v8aircraft.com/jrdalton said:
(Note: Of interest is click on the http://www.v8seabee.com/ and look at the video's. Warning turn volumn down since some are real loud, big sea plane prop at high RPM. I think that is the only one plane they really have going(?), the SeaBee conversion "looking for investors". I gather that is the origin of this company, putting the V8 into SeaBee's on an experimental basis. They list the RV-10 as one of the suitable kit planes but there is no "KIT" just the engnie and drive at this time. As far as price of their reduction drive? A lot? They do list a hydraulic prop gov pad but looking at picture gallery they use a SWASH plate PROP!
http://gallery.v8seabee.com/detail.asp?iType=34&iPic=237.
I think their drive will work with reg Hyd props as well. The reduction drive looks long, so the stock cowl will not work, but heard they are working on a shorter PSRU unit so the stock Lyc cowl can be used.
There is little info on installed weight and cost. Reading there FAQ and there "Operation Cost" I think they are exaggerating the overhaul cost of a Lyc 540 ($40,000) by a factor of over 2 to 2.5. Their fuel burn of 10 gal verses 15 gal per hour is suspect. I doubt that it has 33% better fuel efficiency, the real world and physics gets in the way of these outstanding spacific fuel burns.
My point is proceed with caution. At least with BeltedAirPower you have history and many flying in RV's. If they have a V8 conversion with there reliable philosophy, it would be a safer way to go. The Robinson PSRU with hyd prop gov pad looks good, but at how much weight and cost?)
I know little about Robinson but it may be worth a look. My comment would be a Lycoming as expensive as 540's might be, it will likely cost more and take way longer to build a V8. I don't think V8power has a FWF kit for the RV-10 but if they do, its not going to save you money. If you have to design as you go it will add many 100's of hours to the project. I don't know what your motive is for considering not following "The Plans" of using the recommend engine. If it's cost alone I would really look at going with a used 540 with a homebuilder overhaul with some pro guidance. It is not that hard. Going brand new 540 out the door is about $39,000. Believe it or not they may be cheaper. I can see you getting a core and building it for low mid $20k's. Than you can use the kit parts and all the knowledge and parts for the Lyc, if you goal is to have a plane to fly and not tinker with. Just my personal philosophy. Just not sure if you want to have an experimental auto engine installation that no one else has proven. The Subaru/Mazda/V6 in the two seater RV's has more track record. In the end you have to prepare yourself for the "experiment" not to work real well. There is always that risk.
If you want to go fly the Lyc is the way to go. If you enjoy and extra challenge and having something unique, even if it takes longer and cost the same or more, than the V8 may be the way to go. Keep in mind a Lyc 540 is not that heavy. A LS6 (big block) + PSRU + Radiator + Liquids is going to weigh a lot. You only need 260 HP. Also you will be going away from BeltedAirPowers philosophy which I think is 100% right on for an alternative engine. The Robinson from what I see is electronic and gear/chain. Also with no RV-10 kit yet, designed and proven as BeltedAirPower, you are a test pilot. Not a put down, just an opinion that as a pioneer you can expect a lot of development on your own time and lots of reworks.
After you start down the V8 power road, who knows about performance (and weight) as installed. If I was building a Rocket or -10 I would find a core 540 and tear it down and rebuild it myself. There is no way around expensive engines that make +250 HP with aircraft reliability and hyd prop control. Keep in mind the RV-10 is a hauler, 4 place plane. My concern is the V8 will weigh so much, taking a way from the payload and basically making a 4-place plane into a 2-place payload limited plane with 4 seats.
On this Forum a Rocket pilot posted some video of a flight. Listen to the Lyc 540 purr. The 540 is a awesome engine, consider building to plans, it will save you time and grief.
There is no free lunch folks. When some one says they have an engine that makes more power, burns less gas, cost way less and does not weigh much more than an air-cooled Lyc, my bogosity meter pegs. The V8power guys sound like real nice folks there up in Canada. Give them a call, it might be the ticket for some?
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Too Light?????
Jess...
An aircraft engine too light? Oh dear...what a nice problem. Can't you just move it futher out? The Boeing 787/Dreamliner production is being delayed a few months and Boeing is spending billions in extra design costs in order to shave off a few more pounds. Van and his staff are OBSESSED with lightness. Lightness is good. Very good. Well...within reason of course (I am not advocating putting a Rotax on an RV). Anyway...
1.) Can you extend/modify the engine mount & cowl to deal with the "all alloy" CG issues? How about adding a small header tank? Yes...battery placement will help. And adding the new "Vari-Prop" might help too, no?
2.) How much is the added cost of the "all alloy" setup?
3.) How much weight is saved?
4.) How durable/reliable would it be? More sensitive to overheating?
5.) What happened to the customer with the "all alloy" CG problem? Still flying? How'd it work out?
I think some folks are attracted to the auto engine conversions to save money, but I am attracted for other reasons. I think weight savings, where aircraft are concerned, is worth money. Please tell me more. And thanks again for sticking with this thread.
Dan
Jess Meyers said:
Jess...
An aircraft engine too light? Oh dear...what a nice problem. Can't you just move it futher out? The Boeing 787/Dreamliner production is being delayed a few months and Boeing is spending billions in extra design costs in order to shave off a few more pounds. Van and his staff are OBSESSED with lightness. Lightness is good. Very good. Well...within reason of course (I am not advocating putting a Rotax on an RV). Anyway...
1.) Can you extend/modify the engine mount & cowl to deal with the "all alloy" CG issues? How about adding a small header tank? Yes...battery placement will help. And adding the new "Vari-Prop" might help too, no?
2.) How much is the added cost of the "all alloy" setup?
3.) How much weight is saved?
4.) How durable/reliable would it be? More sensitive to overheating?
5.) What happened to the customer with the "all alloy" CG problem? Still flying? How'd it work out?
I think some folks are attracted to the auto engine conversions to save money, but I am attracted for other reasons. I think weight savings, where aircraft are concerned, is worth money. Please tell me more. And thanks again for sticking with this thread.
Dan
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gmcjetpilot
Well Known Member
More V8 PSRU's
Here is another fancy PSRU or reduction drive with Hyd prop for a V8:
http://www.epi-eng.com/GBX-Mark15.htm
Lots of info on the site.
Here is another fancy PSRU or reduction drive with Hyd prop for a V8:
http://www.epi-eng.com/GBX-Mark15.htm
Lots of info on the site.
cawmd82
Well Known Member
Jaguar V12
A quick perusal of that site is indeed interesting. Perhaps the coolest tidbit is their stated intention to create a bell housing to work on the Jag V12!! For those who think piston planes should have 12 cylinders a cool idea, for those who have ever owned a V12 Jag......maybe another emotion would be provoked----terror, fear, nausea, trembling, etc
Oh well I guess it truly would be EXPERIMENTAL!!
On V12s---Anyone ever here more from the Nagel guys? www.nagelengine.com
A quick perusal of that site is indeed interesting. Perhaps the coolest tidbit is their stated intention to create a bell housing to work on the Jag V12!! For those who think piston planes should have 12 cylinders a cool idea, for those who have ever owned a V12 Jag......maybe another emotion would be provoked----terror, fear, nausea, trembling, etc
Oh well I guess it truly would be EXPERIMENTAL!!
On V12s---Anyone ever here more from the Nagel guys? www.nagelengine.com
pierre smith
Well Known Member
Fix
cawmd82 said:......maybe another emotion would be provoked----terror, fear, nausea, trembling, etc
]/QUOTE]
Yes, and the reason why my XJS has a Chevy 350 in it!
Jess Meyers
Member
chevys
In trying to answer the all alloy 4.3 question, Yes a mount of further length could be done. But in trying to stay with the original philosophy ie.cowl size re-engineering a mount with the proper strength aerodymanic balance there are so many problems that crop up. Our FWF is engineered both from aerodymanic and strength standpoint and the extra cost did not seem to be worth the effort until a totally new plane was developed. Our CG on the RV is right in the middle and it did take a concerted effort to do that. Yes the 350 at 3500 rpm is more than the power for a 10 and yes it would be a development to do it but no more than trying to put another engine in it. The Jag V-12 was usually replaced with a 350 for power and cooling reasons here in the desert, plus the all cast iron 350 was lighter than the al. V-12, we had two we were playing with for the ME 109 project. The engine alone weighed more than the completed plane. The reason we got involved with the auto was the 109 and then it just went from there. The cost of Lyc.s then was only $6000.00 but they were soon gone and it's only up from there. The Late Dr. Harrold kept telling us if done correctly it's just "A liquid cooled V based power plant with an elastometric coupling to the propeller."
In trying to answer the all alloy 4.3 question, Yes a mount of further length could be done. But in trying to stay with the original philosophy ie.cowl size re-engineering a mount with the proper strength aerodymanic balance there are so many problems that crop up. Our FWF is engineered both from aerodymanic and strength standpoint and the extra cost did not seem to be worth the effort until a totally new plane was developed. Our CG on the RV is right in the middle and it did take a concerted effort to do that. Yes the 350 at 3500 rpm is more than the power for a 10 and yes it would be a development to do it but no more than trying to put another engine in it. The Jag V-12 was usually replaced with a 350 for power and cooling reasons here in the desert, plus the all cast iron 350 was lighter than the al. V-12, we had two we were playing with for the ME 109 project. The engine alone weighed more than the completed plane. The reason we got involved with the auto was the 109 and then it just went from there. The cost of Lyc.s then was only $6000.00 but they were soon gone and it's only up from there. The Late Dr. Harrold kept telling us if done correctly it's just "A liquid cooled V based power plant with an elastometric coupling to the propeller."
Jess,
I consider you the elder statesman of the PSRU game, and you've worked with some highly qualified consultants. I'd like to hear your views about gathering torsional test data.
Back when you started, the only practical way to test PSRU's was to fly them and see what fails. You could calculate torsional predictions if so inclined, engineering stiffness and inertia values to minimize vibratory torque values at the resonant intersections. However, verifying the predictions by measuring the results with the running system would have been difficult for a small developer. The problem was (and remains) getting the data off the rotating shaft. In the old days that meant sliprings or analog radio, and both were bulky, noisy, and expensive.
This is 2006. Today you can buy complete off-the-shelf digital data telemetry systems for less than $10K including recording and analysis software and the laptop to record the data. A single channel transmitter is tiny and a wheatstone bridge takes up very little shaft space. Using such a system allows accurate determination of vibratory shaft loads and frequencies, the forces that beat propellers, bearings, shafts, gears and belts until failure.
Torsional engineering began with the steam engine, and today we have all the tools to measure in real time. It is not something you can blow off, because a resonant F1 can easily reach vibratory torques in excess of 100 times mean engine torque. Yet almost all of the current engine conversion companies and PSRU supplies do indeed blow it off. They make no effort to learn fundamental theory, engineer for a specific result, or measure the result. They just run it, hope for the best, and call it "testing". If the prototype lasts awhile, they start selling.
I like engine conversions, and I've done one. I've deadsticked a dead drive (from a vendor), modeled it, designed a better one, and pulled telemetry data. Because I have real data, I could design the next one to be far better than the last. It took a vast amount of educational help from a mentor and a lot of work, but it was done on a homebuilder's budget.
Vendors are business people with for-profit ventures. People's lives and dreams hang on their products. Why hasn't torsional telemetry become an industry standard?
Dan Horton
I consider you the elder statesman of the PSRU game, and you've worked with some highly qualified consultants. I'd like to hear your views about gathering torsional test data.
Back when you started, the only practical way to test PSRU's was to fly them and see what fails. You could calculate torsional predictions if so inclined, engineering stiffness and inertia values to minimize vibratory torque values at the resonant intersections. However, verifying the predictions by measuring the results with the running system would have been difficult for a small developer. The problem was (and remains) getting the data off the rotating shaft. In the old days that meant sliprings or analog radio, and both were bulky, noisy, and expensive.
This is 2006. Today you can buy complete off-the-shelf digital data telemetry systems for less than $10K including recording and analysis software and the laptop to record the data. A single channel transmitter is tiny and a wheatstone bridge takes up very little shaft space. Using such a system allows accurate determination of vibratory shaft loads and frequencies, the forces that beat propellers, bearings, shafts, gears and belts until failure.
Torsional engineering began with the steam engine, and today we have all the tools to measure in real time. It is not something you can blow off, because a resonant F1 can easily reach vibratory torques in excess of 100 times mean engine torque. Yet almost all of the current engine conversion companies and PSRU supplies do indeed blow it off. They make no effort to learn fundamental theory, engineer for a specific result, or measure the result. They just run it, hope for the best, and call it "testing". If the prototype lasts awhile, they start selling.
I like engine conversions, and I've done one. I've deadsticked a dead drive (from a vendor), modeled it, designed a better one, and pulled telemetry data. Because I have real data, I could design the next one to be far better than the last. It took a vast amount of educational help from a mentor and a lot of work, but it was done on a homebuilder's budget.
Vendors are business people with for-profit ventures. People's lives and dreams hang on their products. Why hasn't torsional telemetry become an industry standard?
Dan Horton
PowerSport did a full TV study on their drive. Eggenfellner also evaluated theirs in conjunction with MT I believe. Jess' drives have accumulated thousands of hours in flight as has Eggenfellner, RAF, RWS etc. No better way to validate than that. NSI uses a Sprague clutch. Marcotte has modified their drive bushing mounting system and use a stiffer bushing than earlier versions to move TV outside the normal rpm ranges. Belt systems are prone to TV problems just like any other drive system as proven by the extensive work done by Don Hessenaur.
I agree that most other drive companies have not tested TVs however it must be understood that this is only valid within the range of prop MIs tested on a specific engine type. As soon as a customer installs a lighter or heavier prop or uses the drive on an untested engine, problems can surface. Rotax specifies a range of prop masses suitable for their drives which is the best route in my view.
I agree that most other drive companies have not tested TVs however it must be understood that this is only valid within the range of prop MIs tested on a specific engine type. As soon as a customer installs a lighter or heavier prop or uses the drive on an untested engine, problems can surface. Rotax specifies a range of prop masses suitable for their drives which is the best route in my view.
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gmcjetpilot
Well Known Member
Simple by design
I am not disputing anything you said just pointing out analytical analysis of a belted drive is straight forward. Clearly measuring stress, strain and vibration is worthy of any device that goes on an aircraft, belted drive or not. Just in my opinion, of all the PSRU's, the belted system is pretty stright forward and has less unknowns that a gear drive, which makes me more comfortable with it, even with out measurement or torsional response than other drives. Cheers
PS: I got a quote e-mailed back from V8seabee.com, for a LS1, reduction unit for a RV-10, just under $40,0000, plus another $11,000 for a MT prop. It was several weeks to get the quote. It was pretty sparse on info. Unfortuantely I can't find it on my computer right now. Not sure quite what you get since the quote was not super clear, but it was for the LS1 or LS6 for more money of course. The stock cowl will work; they say they are working on a new reduction drive that is shorter to maintain the use of the stock RV cowl. Any way, engine mount or not, $40K! Again you could go with a new IO540 for way less, which is what I would do. The weight claims are sketchy, and not sure what weights they where comparing, may be a GSIO-480. I assume there is no radiator, exhaust or true installation kit since these are options listed on their site and the quote did not specify it. So for just the engine and reduction, nothing else, $40K? Wow. I don't want to hear about people complaining about Lycoming prices any more. They look like a bargain when you hear about the alternative prices.
Hey dan that is cool interesting stuff. I used to strain gage stuff back in the day for structural analysis and certification. However I just want to point out the Belted Air Power guys of course use a Belt, which kind of takes the torsional harmonics out of the picture, which is why it's so elegant. Analytically the drive shaft is so stiff it is not critical and the belt is such and effective damper that harmonics are not critical.DanH said:
I am not disputing anything you said just pointing out analytical analysis of a belted drive is straight forward. Clearly measuring stress, strain and vibration is worthy of any device that goes on an aircraft, belted drive or not. Just in my opinion, of all the PSRU's, the belted system is pretty stright forward and has less unknowns that a gear drive, which makes me more comfortable with it, even with out measurement or torsional response than other drives. Cheers
PS: I got a quote e-mailed back from V8seabee.com, for a LS1, reduction unit for a RV-10, just under $40,0000, plus another $11,000 for a MT prop. It was several weeks to get the quote. It was pretty sparse on info. Unfortuantely I can't find it on my computer right now. Not sure quite what you get since the quote was not super clear, but it was for the LS1 or LS6 for more money of course. The stock cowl will work; they say they are working on a new reduction drive that is shorter to maintain the use of the stock RV cowl. Any way, engine mount or not, $40K! Again you could go with a new IO540 for way less, which is what I would do. The weight claims are sketchy, and not sure what weights they where comparing, may be a GSIO-480. I assume there is no radiator, exhaust or true installation kit since these are options listed on their site and the quote did not specify it. So for just the engine and reduction, nothing else, $40K? Wow. I don't want to hear about people complaining about Lycoming prices any more.
They look like a bargain when you hear about the alternative prices.
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<<..... use a Belt, which kind of takes the torsional harmonics out of the picture, which is why it's so elegant. Analytically the drive shaft is so stiff it is not critical and the belt is such and effective damper that harmonics are not critical.>>
I'm sorry George, but the above is quite incorrect in several ways.
I don't wish to enter into a detailed explanation. You're an engineer, so I would rather show you results, data taken from telemetry. The following is from a successful drive following much torsional design work. The previous bad drive could hit nearly 2000 ft-lbs of vibratory torque on a full-throttle pass though the F1 frequency. This one was nowhere near that. BOTH were belt drives.
This is vibratory torque only, not engine torque output, at at 100 RPM increments, steady state throttle. Subject was an I-3 Suzuki. The belt was a Dayco RPP Panther, not the far stiffer Gates PolyChain. The airframe (JN-4C replica) required operation through the critical speed around 1500 RPM (a resonant intersection of system F1 and the gas pressure oscillation frequency), so the prime design goal was to control resonant amplitude. With a different airframe or an engine with more cylinders it may have been practical to push the F1 resonant speed down below idle, or like Rotax simply raise the idle speed requirement. This system used a Lovejoy Centaflex in parallel with a viscous damper. Damping value was not high. Undamped runs were made for comparison; undamped resonance peak was about 180 ft-lbs, so the damper was working nicely. Run #1 in blue, run #2 in green, average in black. BTW, you can see the beginnings of the F2 peak at the full throttle end of the operating range.
Anything that torsionally stiffened the system would push the F1 intersection further up into the operating range. The vibratory amplitudes would be much higher. If the F1 peak fell within a common operating range, drive life would be quite short.
Trust me George, a belt is a connecting element, not a magic wand. In truth, a belt adds frequencies to the mix, quite the opposite of the views expressed in far too many internet forums. That is a discussion for another time. Right now I'd just like to hear what Jess has to say about live measurement.
Dan Horton
I'm sorry George, but the above is quite incorrect in several ways.
I don't wish to enter into a detailed explanation. You're an engineer, so I would rather show you results, data taken from telemetry. The following is from a successful drive following much torsional design work. The previous bad drive could hit nearly 2000 ft-lbs of vibratory torque on a full-throttle pass though the F1 frequency. This one was nowhere near that. BOTH were belt drives.
This is vibratory torque only, not engine torque output, at at 100 RPM increments, steady state throttle. Subject was an I-3 Suzuki. The belt was a Dayco RPP Panther, not the far stiffer Gates PolyChain. The airframe (JN-4C replica) required operation through the critical speed around 1500 RPM (a resonant intersection of system F1 and the gas pressure oscillation frequency), so the prime design goal was to control resonant amplitude. With a different airframe or an engine with more cylinders it may have been practical to push the F1 resonant speed down below idle, or like Rotax simply raise the idle speed requirement. This system used a Lovejoy Centaflex in parallel with a viscous damper. Damping value was not high. Undamped runs were made for comparison; undamped resonance peak was about 180 ft-lbs, so the damper was working nicely. Run #1 in blue, run #2 in green, average in black. BTW, you can see the beginnings of the F2 peak at the full throttle end of the operating range.
Anything that torsionally stiffened the system would push the F1 intersection further up into the operating range. The vibratory amplitudes would be much higher. If the F1 peak fell within a common operating range, drive life would be quite short.
Trust me George, a belt is a connecting element, not a magic wand. In truth, a belt adds frequencies to the mix, quite the opposite of the views expressed in far too many internet forums. That is a discussion for another time. Right now I'd just like to hear what Jess has to say about live measurement.
Dan Horton
<<PowerSport did a full TV study on their drive.>>
Yes they did, and I for one was tickled to death. However, I wish they would have published the data. As I recall (a chancy thing when you're over 50) all they put on the web would paraphrase as "everything is great".
<<Eggenfellner also evaluated theirs in conjunction with MT I believe.>>
Again, anything published? BTW, I watched a guy remove a trashed Egg gearbox yesterday.
<<NSI uses a Sprague clutch.>>
And as long as you don't operate in the lock/unlock range it lives.
<<Marcotte has modified their drive bushing mounting system and use a stiffer bushing than earlier versions to move TV outside the normal rpm ranges.>>
How does one know it is outside the operating range?
<<...valid within the range of prop MIs tested on a specific engine type. As soon as a customer installs a lighter or heavier prop or uses the drive on an untested engine, problems can surface. Rotax specifies a range of prop masses suitable for their drives which is the best route in my view.>>
Quite true, but as you note it is possible to cover a rather wide range of inertas. Most users seem to be able to accept the idea of an inertia limit, although a few do go off the reservation.
Dan Horton
Yes they did, and I for one was tickled to death. However, I wish they would have published the data. As I recall (a chancy thing when you're over 50) all they put on the web would paraphrase as "everything is great".
<<Eggenfellner also evaluated theirs in conjunction with MT I believe.>>
Again, anything published? BTW, I watched a guy remove a trashed Egg gearbox yesterday.
<<NSI uses a Sprague clutch.>>
And as long as you don't operate in the lock/unlock range it lives.
<<Marcotte has modified their drive bushing mounting system and use a stiffer bushing than earlier versions to move TV outside the normal rpm ranges.>>
How does one know it is outside the operating range?
<<...valid within the range of prop MIs tested on a specific engine type. As soon as a customer installs a lighter or heavier prop or uses the drive on an untested engine, problems can surface. Rotax specifies a range of prop masses suitable for their drives which is the best route in my view.>>
Quite true, but as you note it is possible to cover a rather wide range of inertas. Most users seem to be able to accept the idea of an inertia limit, although a few do go off the reservation.
Dan Horton
I'm not sure why a drive manufacturer like Eggenfellner or PowerSport would publish such data as these are only used on their specific engines and with the props they recommend. For companies like Marcotte and RWS, information on the limits of prop weights/ MIs would be very welcome but as I said before, they simply cannot test all props and engine combos their drives are used on or they'd be selling $10K drives to pay for it all.
RWS uses a very different/ interesting approach in staying out of the bad TV ranges. The Marcotte design would at least allow the user to change drive bushing durometer if testing/instrumentation showed bad TV. Their original bushings were quite low durometer and several users reported TV problems at various rpm ranges with props in the 20-30 pound range (MI unknown) on the commonly fitted 4 cylinder Subarus. The newer bushings have solved the noticeable TV on these for many. Eggenfellner has changed flywheel mass and also introduced a two piece damped flywheel to address some concerns whith their designs.
It is comparitively simple to design a drive for a specific engine/propeller and ensure that there is no bad TV within the operating range through testing. Very much harder to do it for many engine, flywheel and prop combos. Just $$$$ and time. It is not the instrumentation that is expensive these days, it is the purchase, setup and running of many different engines and propellers that is the killer for these small companies.
Dan, I'd also be interested in your thoughts on the Egg drive failure. Was this TV, lubrication, bad heat treating, assembly, machining etc. related?
RWS uses a very different/ interesting approach in staying out of the bad TV ranges. The Marcotte design would at least allow the user to change drive bushing durometer if testing/instrumentation showed bad TV. Their original bushings were quite low durometer and several users reported TV problems at various rpm ranges with props in the 20-30 pound range (MI unknown) on the commonly fitted 4 cylinder Subarus. The newer bushings have solved the noticeable TV on these for many. Eggenfellner has changed flywheel mass and also introduced a two piece damped flywheel to address some concerns whith their designs.
It is comparitively simple to design a drive for a specific engine/propeller and ensure that there is no bad TV within the operating range through testing. Very much harder to do it for many engine, flywheel and prop combos. Just $$$$ and time. It is not the instrumentation that is expensive these days, it is the purchase, setup and running of many different engines and propellers that is the killer for these small companies.
Dan, I'd also be interested in your thoughts on the Egg drive failure. Was this TV, lubrication, bad heat treating, assembly, machining etc. related?
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Re the Egg box: The propshaft had moved forward, extending from the case perhaps an additional 1/4". I don't know why, as I know nothing about the internal construction of the gearbox.
In addition, I observed a small quantity of fine, shiny metalic debris on the face of the pilot bearing seal when I looked into the splined hole in the center of the flywheel assembly. The owner did not remove the flywheel while I was there, so I have no idea if the metalic debris actually indicated a problem. I understand there is some sort of spring-based soft element in the flywheel center.
The owner said this was the second failure for this gearbox.
Dan
In addition, I observed a small quantity of fine, shiny metalic debris on the face of the pilot bearing seal when I looked into the splined hole in the center of the flywheel assembly. The owner did not remove the flywheel while I was there, so I have no idea if the metalic debris actually indicated a problem. I understand there is some sort of spring-based soft element in the flywheel center.
The owner said this was the second failure for this gearbox.
Dan
Rotary10-RV
Well Known Member
DanH said:
There are a multitude of reasons why a gearbox can fail, torsional vibration is only one. That said I wanted to state flat-out that a belt drive DOES NOT eliminate torsional vibration problems. A very interesting paper/article on TV was written by one of the guys that did the drive for the BD-5. They had it all, belt, drive shaft, 2-cycle engine rubber mounted. There were several interesting failure modes. One caused a stub drive shaft to be thrown thru a wall from the test bench. Google BD-5 and tortional vibration and you'll be able to find the paper. It should be required reading for anyone designing a drive.
BTW Failures of Eggenfellner gearboxes have been VERY rare. IF your aquantaince has burned 2 I would be trying to find out what he is doing differently.
Bill Jepson
gmcjetpilot
Well Known Member
Always room for learning
What I assumed was Belted power did size components and do basic hand calculations accounting for torsional stiffness. That can be done by simple hand crank calcs. Now a days there is advanced FEM, finite element analysis, to design for vibration response. With that said actual measurements should be done to validate the analysis, at least once.
Take care.
The BD-5 had other issues back in the day, one being the LONG drive shaft, begging for harmonics. The Belted Air Power System is quite stout, compact and simple, a brut force approach if you will. You are right, you can't look at it and say, it's belted so its fine. I'm making some assumptions about the BAP unit in particular (not all belt drives). I could be wrong. We'll see what Jess says.
I see how my comments can be interpreted as there are never any problems with belt drives and torsional vibration, which is not true of course. I was saying, IMHO, severe vibration problems are unlikely with a heavy duty compact design like the Belted Air Power unit. I could be wrong. As DanH said you don't know until you measure it. I don't know the power pulse of a V6 and the stiffness of the belt, but it seems that it would be easy to calculate with simple analysis the natural frequencies and potential for harmonics. I agree with you all, testing is needed and calcs and assumptions can be off.
Hey Dan don't be sorry, I am always learning new stuff. I only got a quick study of your comments, but I'll look into it and get back to you. I do understand that you can have harmonics even with a belt in there. I did make some assumptions based on inspection of the Belted Air power Unit, which may not be correct. My assumption is the shafts, belt, bearing supports and frame are so stiff (overkill), with some belt damping, it would not be torsion ally critical. Like you say you don't know unless you measure it. I can't argue with that. I was not making a statement about any drive using a belt. I agree it is not a magic wand, just one part.DanH said:
What I assumed was Belted power did size components and do basic hand calculations accounting for torsional stiffness. That can be done by simple hand crank calcs. Now a days there is advanced FEM, finite element analysis, to design for vibration response. With that said actual measurements should be done to validate the analysis, at least once.
Take care.
Torsional vibration threw the shaft off? The shaft on the Belted Air Power is supported at both ends and throwing the shaft is hard to envision; I'll also get back to you when I read the article. There's had to be a LOT more going on to throw a shaft off, more than just the belt drive. I suspect it was a light duty design that did not have proper supports.Rotary10-RV said:
The BD-5 had other issues back in the day, one being the LONG drive shaft, begging for harmonics. The Belted Air Power System is quite stout, compact and simple, a brut force approach if you will. You are right, you can't look at it and say, it's belted so its fine. I'm making some assumptions about the BAP unit in particular (not all belt drives). I could be wrong. We'll see what Jess says.
I see how my comments can be interpreted as there are never any problems with belt drives and torsional vibration, which is not true of course. I was saying, IMHO, severe vibration problems are unlikely with a heavy duty compact design like the Belted Air Power unit. I could be wrong. As DanH said you don't know until you measure it. I don't know the power pulse of a V6 and the stiffness of the belt, but it seems that it would be easy to calculate with simple analysis the natural frequencies and potential for harmonics. I agree with you all, testing is needed and calcs and assumptions can be off.
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TV Articles
Here are links to the work done by Don Hessenaur I mentioned a few days ago: http://www.prime-mover.org/engines/Torsional/
Also links to one by Keith Spreuer who is now flying his EG33 powered Cozy. Keith is an engineer and has some useful equations for estimating MI for propellers.
Plus one by Bill Husa on redrives from Sport Aviation.
Happy reading.
Here are links to the work done by Don Hessenaur I mentioned a few days ago: http://www.prime-mover.org/engines/Torsional/
Also links to one by Keith Spreuer who is now flying his EG33 powered Cozy. Keith is an engineer and has some useful equations for estimating MI for propellers.
Plus one by Bill Husa on redrives from Sport Aviation.
Happy reading.
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<<I'm not sure why a drive manufacturer like Eggenfellner or PowerSport would publish such data as these are only used on their specific engines and with the props they recommend.>>
Did a market survey of sorts a few years ago, as I was kicking around the idea of buying a telemetry rig. The question (to paraphrase) was "What would you be willing to pay for a torsional telemetry report on your engine/redrive combination?". The majority of respondents felt it was worth $1000. I think a $1000 premium would be a pretty good incentive if I were a redrive manufacturer.
The expensive firewall forwand package vendors might consider "conquest" customers, folks who currently stick with conventional engines because they don't accept offhand assurances. I'm satisfied that my new IO-390 will be happy paired with a 74" Hartzell BA because (1) the Lycoming engineers know precisely why they put pendulum absorbers on the crank, and (2) the Hartzell guys did telemetry. Neither shared the actual data with me, but I'm OK with that. I am SURE they have real stress values. I am not sure the conversion vendors have any measured values. Want my money? Show me.
Remember, I like auto conversions. I just think folks are accepting a woefully low level of real engineering, and it is holding back progress.
Dan Horton
Did a market survey of sorts a few years ago, as I was kicking around the idea of buying a telemetry rig. The question (to paraphrase) was "What would you be willing to pay for a torsional telemetry report on your engine/redrive combination?". The majority of respondents felt it was worth $1000. I think a $1000 premium would be a pretty good incentive if I were a redrive manufacturer.
The expensive firewall forwand package vendors might consider "conquest" customers, folks who currently stick with conventional engines because they don't accept offhand assurances. I'm satisfied that my new IO-390 will be happy paired with a 74" Hartzell BA because (1) the Lycoming engineers know precisely why they put pendulum absorbers on the crank, and (2) the Hartzell guys did telemetry. Neither shared the actual data with me, but I'm OK with that. I am SURE they have real stress values. I am not sure the conversion vendors have any measured values. Want my money? Show me.
Remember, I like auto conversions. I just think folks are accepting a woefully low level of real engineering, and it is holding back progress.
Dan Horton
