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  #11  
Old 11-19-2019, 05:28 PM
Turbo69bird Turbo69bird is offline
 
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Quote:
Originally Posted by rv6ejguy View Post
There are a number of turboed Lycomings and Contis, mostly on Reno racers running crazy levels of boost.

Turbos can be rigidly mounted to the exhaust ports with very thick tubing but watch the thermal expansion at the junction of the pipes while handling the mechanical and vibrational loadings. Other method is to fix the turbo to the engine with a stout mount and use slip joints or bellows to handle the thermal expansion in the piping. This is lighter and more reliable in the long term.

You don't need a blow off valve on an airplane- or car for that matter. More weight and another thing to go wrong.

For RVs with their low Vne, boosted engines don't make a lot of sense for most cross country work at altitude and cooling in the climb on a hot day could be challenging.

The blow off valve keeps the turbo from building pressure in the intake column and forcing the turbo to spin backwards without it when the throttle blades close it will spin backwards this is from 100,000 rpm and then people will say ďturbos aren't reliable I keep breaking mine.Ē lol. Thatís why they came out with fat shaft turbos it was bandaid for people not running BOVs of course you shut the butterflies a lot less in an airplane than in a car. This is for blow through applications of course , draw through is what blew up so many performance boats in the 70s and gave turbos a really bad name.
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  #12  
Old 11-19-2019, 05:31 PM
Turbo69bird Turbo69bird is offline
 
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Originally Posted by Flying EMT View Post
My helicopter has a IO360 turboed up to 210 hp so itís possible to turbo a lycoming. I thing the main problems would be fitting it in the cowl and getting rid of the heat. In the long run, I think it would only be beneficial for the planes that live at high altitudes. Ben
I have some good friends over by you w turbos cars you probably see them tearing up the streets in LI ones a 4cyl Pontiac making 800 hp half a Pontiac V8 in a GTO cool car. Out of the Shirley area. Another Th ET 455 v8 in port Jeff area.
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Special Thanks to Fred Stucklen


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  #13  
Old 11-19-2019, 08:20 PM
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rv6ejguy rv6ejguy is offline
 
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Originally Posted by Turbo69bird View Post
The blow off valve keeps the turbo from building pressure in the intake column and forcing the turbo to spin backwards without it when the throttle blades close it will spin backwards this is from 100,000 rpm and then people will say “turbos aren't reliable I keep breaking mine.” lol. That’s why they came out with fat shaft turbos it was bandaid for people not running BOVs of course you shut the butterflies a lot less in an airplane than in a car. This is for blow through applications of course , draw through is what blew up so many performance boats in the 70s and gave turbos a really bad name.
I've built turbocharged road race, street and aircraft engines professionally for 40 years. Never used a blow off valve on one of them and never had a turbo failure on one of them either. None of the IMSA turbo engines from that great era used them to my knowledge...

I've assisted several Reno Sport Class winners running turbo engines- no BOVs there either, running over 90 inches.

You may notice in my signature that I've been flying a turbocharged RV for over 16 years- no blow off valve, original turbo.
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Turbo Subaru EJ22, SDS EFI, Marcotte M-300, IVO, Shorai- RV6A C-GVZX flying from CYBW since 2003- 436.1 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi2.htm



Last edited by rv6ejguy : 11-20-2019 at 06:51 AM.
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  #14  
Old 11-19-2019, 08:57 PM
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F1Boss F1Boss is offline
 
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Default The saying goes..

Quote:
Originally Posted by Paddy View Post
More cylinders...
ďThere is no replacement for displacement.Ē

FWIW the 550-N series Continental (found in the Cirrus series) has at min 310HP at max 325 in the stock configuration . Also has 100 more lbs/ft of torque when compared with a stock 260HP 540. Torque is what makes your airplane go.

4 crank counterweights in the 550 leads to a very smooth ride too.

Installed weight is about 10lbs more than the Lyc. Fuel specifics are quite a bit better too.

Just sayiní...
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  #15  
Old 11-20-2019, 12:30 AM
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rv8ch rv8ch is offline
 
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Default What will you do with the power?

Quote:
Originally Posted by Turbo69bird View Post
...Anything you know of that will make more Hp for the experimental community is good to post.

I'm amazed that there's not more experimenting posted with experimentals in this area.
Jeff, just curious, what will you do with that extra power in an RV? Is it for better climb? Flying much faster than VNE? Bragging rights? Racing? Towing a trailer?
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  #16  
Old 11-20-2019, 06:50 AM
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rv6ejguy rv6ejguy is offline
 
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Quote:
Originally Posted by F1Boss View Post
ďThere is no replacement for displacement.Ē

FWIW the 550-N series Continental (found in the Cirrus series) has at min 310HP at max 325 in the stock configuration . Also has 100 more lbs/ft of torque when compared with a stock 260HP 540. Torque is what makes your airplane go.

4 crank counterweights in the 550 leads to a very smooth ride too.

Installed weight is about 10lbs more than the Lyc. Fuel specifics are quite a bit better too.

Just sayiní...
Hp is the determining factor in quantifying aircraft performance however. The extra 60 hp will be noticeable in climb performance mainly. Only worth a few percent in top speed.
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Ross Farnham, Calgary, Alberta
Turbo Subaru EJ22, SDS EFI, Marcotte M-300, IVO, Shorai- RV6A C-GVZX flying from CYBW since 2003- 436.1 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi2.htm


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  #17  
Old 11-20-2019, 11:00 AM
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skylor skylor is offline
 
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Default Torque

Quote:
Originally Posted by F1Boss View Post
“There is no replacement for displacement.”

Torque is what makes your airplane go.
Mark, Mark, Mark,

Torque alone doesn't make anything go! Torque is a measurement of force only and is but one component required to motivate something. To actually move something, we need to do "work" which is defined as force x distance. And doing that "work" in a finite amount of time requires "power" which is amount of work performed in specific amount of time or work/time. For example, a car's brake can apply force or "torque" to the wheel(s) of a car parked on a hill to keep it from rolling, but it certainly can apply torque while rotating the wheel (work) and it definitely can't rotate the wheel very fast...

Let's try a little though experiment:

Imagine a person with a long torque wrench, say like this 3/4" drive 600 ft-lb model Torque Wrench

With this torque wrench, we can apply up to 600 ft-lbs of torque to something...maybe even a prop hub. How much torque did you say that IO-550-N makes at 2700 RPM and 310 HP?*

OK, so said person (or people) can use that wrench to apply torque to our airplane's prop hub, but to make the plane move we actually have to turn that prop, i.e. do work on it. Of course, even though our torque wrench person is capable of applying a lot of torque with that torque wrench, he's probably going to get tired after trying to turn our propeller more than a few revolutions (doing all that "work") but more importantly, he probably can't turn it very fast while applying all that torque, certainly not 2700 RPM. I.E. he can't make much power.

So you see, torque is not what makes airplanes go!

*So the IO-550-N making 310 hp at 2700 RPM is producing 603 ft-lbs of torque. How much power do we get with 603 ft-lbs of torque at only 2000 RPM? About 230. Is the plane going to go as fast with that same torque at 2000 RPM? Thus, as I said, it's actually power that makes our airplanes go fast.

Skylor

p.s. Horsepower = Torque*RPM/5252. Torque is our measurement of force, "revolution" is our measurement of distance (work) and "per minute" is our "over time". Power = work over time (work/time). The 5252 is simply a unit conversion factor of 550*60/Pi. Part of the reason that it's believed that "torque" is what makes things go is because aircraft engine output figures are very often compared at the same RPM (2700) and thus the torque values of engines of different power are directly comparable...but torque without a measurement of speed (RPM) does not tell us anything about the capability of an engine and how fast it can make an airplane go.

Last edited by skylor : 11-20-2019 at 11:19 AM.
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  #18  
Old 11-20-2019, 01:02 PM
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rvisnext rvisnext is offline
 
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Location: WA
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Default $$$

Quote:
Originally Posted by skylor View Post
Mark, Mark, Mark,

Torque alone doesn't make anything go! Torque is a measurement of force only and is but one component required to motivate something. To actually move something, we need to do "work" which is defined as force x distance. And doing that "work" in a finite amount of time requires "power" which is amount of work performed in specific amount of time or work/time. For example, a car's brake can apply force or "torque" to the wheel(s) of a car parked on a hill to keep it from rolling, but it certainly can apply torque while rotating the wheel (work) and it definitely can't rotate the wheel very fast...

Let's try a little though experiment:

Imagine a person with a long torque wrench, say like this 3/4" drive 600 ft-lb model Torque Wrench

With this torque wrench, we can apply up to 600 ft-lbs of torque to something...maybe even a prop hub. How much torque did you say that IO-550-N makes at 2700 RPM and 310 HP?*

OK, so said person (or people) can use that wrench to apply torque to our airplane's prop hub, but to make the plane move we actually have to turn that prop, i.e. do work on it. Of course, even though our torque wrench person is capable of applying a lot of torque with that torque wrench, he's probably going to get tired after trying to turn our propeller more than a few revolutions (doing all that "work") but more importantly, he probably can't turn it very fast while applying all that torque, certainly not 2700 RPM. I.E. he can't make much power.

So you see, torque is not what makes airplanes go!

*So the IO-550-N making 310 hp at 2700 RPM is producing 603 ft-lbs of torque. How much power do we get with 603 ft-lbs of torque at only 2000 RPM? About 230. Is the plane going to go as fast with that same torque at 2000 RPM? Thus, as I said, it's actually power that makes our airplanes go fast.

Skylor

p.s. Horsepower = Torque*RPM/5252. Torque is our measurement of force, "revolution" is our measurement of distance (work) and "per minute" is our "over time". Power = work over time (work/time). The 5252 is simply a unit conversion factor of 550*60/Pi. Part of the reason that it's believed that "torque" is what makes things go is because aircraft engine output figures are very often compared at the same RPM (2700) and thus the torque values of engines of different power are directly comparable...but torque without a measurement of speed (RPM) does not tell us anything about the capability of an engine and how fast it can make an airplane go.
Iím sorry but I have to respectfully disagree with both of you, what makes airplanes go is money, lots of money. -Neil
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  #19  
Old 11-20-2019, 01:09 PM
Turbo69bird Turbo69bird is offline
 
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[quote=rv6ejguy;1387438]I've built turbocharged road race, street and aircraft engines professionally for 40 years. Never used a blow off valve on one of them and never had a turbo failure on one of them either. None of the IMSA turbo engines from that great era used them to my knowledge...

I've assisted several Reno Sport Class winners running turbo engines- no BOVs there either, running over 90 inches.

You may notice in my signature that I've been flying a turbocharged RV for over 16 years-


So first off Iím happy to meet another turbo guy on here especially one flying a turbo RV. I would really like To see pictures of the set up and how you accomplished that.

I raced cars since 1987 been involved with drag racing, performance boats, atv racing and some Road racing mostly GT1.
Turbos are awesome and Iíve taught guys all over the world about them, My turbo set ups are in Australia, New Zealand uk, most everywhere.
I made my own headers in China for turbocharging Pontiacs so that guys could afford the systems here during a bleak economy. And helped size race turbos come up w cam grinds etc, for people since 2004. I think every car in should have turbo and a big one at that. Lol. I make 1000 hp on. A stock block , stock cast crank, iron heads.
and cruise at 17mpg with a 3.73 gear and the car stays cool as ice when out of boost. It far surpasses the naturally aspirated set ups Iíve run. I put 160 track passes a year on my engine for many years running 9 sec passes and drive it on the street and itís got 9 years on it without even a spark plug change. So I lam
A big fan of turbos. And I appreciate everything youíve done with turbos as well. Maybe I can learn something , I do still learn things every day about just about everything, that Iíve done for years. New ideas new ways and new products come up daily
And when you stop learning is when your in trouble . I never have a my way is the only way attitude towards anything

so Iíll ask you some questions.

Where does the fan blow the air when the butterflies close?

Does the turbo continue to spin freely without a blow off valve, and if so how?

Doesnít that air itís blowing continue to blow and build up and eventually spin the turbo backwards?

Not saying it canít be done, but
Just because someone has done something it doesnít make it the best way to do it.
Can you get away without it, possibly Thatís a different question.

Lots of guys used draw through systems too but thatís what almost killed the turbo industry. Only the popularity of blow through turbos ion tractor trailers vs superchargers. And the resurgence of cars (mustangs specifically) n the early 90s like racin Jason betwardas mustang revived the turbo movement.


Id like To see a bunch of turbo RVs flying around, that would be great Iíd especially like to see a low budget set up put together thatís safe and reliable.
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Special Thanks to Fred Stucklen


While I'm not a builder if I happen to give advice , I will not be responsible for damage to equipment, your ego, parts, world wide power outages, spontaneously generated black holes, planetary disruptions, or personal injury that may result from the use of this advice.
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  #20  
Old 11-20-2019, 01:13 PM
Turbo69bird Turbo69bird is offline
 
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Quote:
Originally Posted by rv8ch View Post
Jeff, just curious, what will you do with that extra power in an RV? Is it for better climb? Flying much faster than VNE? Bragging rights? Racing? Towing a trailer?
Well for me it would be better climb out personally. My RV is far faster than I need and I’m kind of a
Slow flyer anyway. (Getting old I guess)
I just like HP on tap. Doesn’t mean I’d need to use it. It’s mainly just that you don’t see any aftermarket parts much I understand it’s because of the certified nature of most airplanes but there’s a huge aftermarket potential here for experimentals. Checked out SDS site and that is exactly what I’m
Taking about.
He’s in the right track here there’s LOTS of potential in the aftermarket not being realized here. Maybe because the RV is so good to start with but for guys w earlier built RVs w 150 160 hp engines there’s got to be some bolt on parts that could make some more HP torque. Different ratio rocker arms maybe ? Just getting the conversation going really.
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Special Thanks to Fred Stucklen


While I'm not a builder if I happen to give advice , I will not be responsible for damage to equipment, your ego, parts, world wide power outages, spontaneously generated black holes, planetary disruptions, or personal injury that may result from the use of this advice.

Last edited by Turbo69bird : 11-20-2019 at 01:24 PM.
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