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The Lycosaurus is actually a crocodile.

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Captain Avgas

Well Known Member
I am re-printing this posting of mine from the depths of an Eggenfelner thread to the General Discussions area at the prompting of several readers. They believe it might be worthwhile reading for those contemplating the purchase of an engine.

The oft quoted argument that auto engines are more advanced than Lycomings is totally misleading. And it is the one single argument that most encourages experimental builders (and mechanically illiterate non gear heads in particular) to instal auto engines.

In reality the zenith of the piston engine was WW2 when literally billions of dollars were thrown at engine development and massive research and development was undertaken by all the major protagonists.

Virtually every "innovative" development that appeared in auto engines decades later appeared on aircraft piston engines during WW2. I refer to multiple valves per cylinder, turbo charging, super charging, intercoolers, over head camshafts, etc etc etc.

The reason that the Lycoming doesn't have these features is purely because it doesn't need them. The Lycoming is not a dinosaur...it is a crocodile. It is perfectly adapted technologically for it's environment.

The Lycoming is not outdated because it does not have four valves per cylinder. It doesn't NEED four valves per cylinder. At a steady 2300 to 2700 RPM four valves per cylinder will not improve performance....it would simply introduce a greater parts count and increase risk of failure for no gain.

The same can be said of complex engine management systems based on the integrated circuit which runs your electronic fuel injection system on your car. Do I want, or NEED these things on my Lycoming at a steady 2400RPM...no way. What I want is a simple, mechanical fuel injection system and a dual ignition system with intrinsic redundancy (which implies 2 plugs per cylinder). Does a car engine give you this ?

There are now 3 major competitive players in the Lycoming/Lyclone market and they are all struggling to find any way to make any truly significant technical improvement to the basic engine.

The Lycoming is not an outdated product....it is a VERY REFINED product, and nothing else on the market in the horsepower range offers anything like the power to weight ratio or reliability (not to mention ease of maintenance).
__________________
 
Captain Avgas said:
The Lycoming is not a dinosaur...it is a crocodile. It is perfectly adapted technologically for it's environment.
Click to expand...

Excellent Post!

When choosing an engine for your experimental project, you want one that has survived, adapted, is easy to maintain.

Most builders don't think of re-sale when they are building, which is very short sighted. There are tons of RV's bought & sold every year, and the market is growing. Aircraft with "alternative engines" just don't sell as well. The money you think you are saving up front by installing an alternative engine will be lost (and then some) when it comes time to sell.
 
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Capt A-
You made a few excellent points regarding the Lycomming strengths (that it is well suited to its current task) and ignored a few of its weaknesses that (I believe) contradicts your premise. If anything, the lack of engine development drives airframe designs.

You mentioned that the design is "well adapted"... because of the extreme costs involved in changing a certified design, adaptations (improvements?) are in fact rare. The biggest downside (my opinion) is that the engines have very low production numbers compared to the alternatives, which makes them and their replacement parts obscenely overpriced for what is delivered, and drives legal costs per unit through the roof.

An engine is simply an engine- they all produce some work per btu input. For aircraft, the power to weight, reliability, ease of use, and cost are all important things to consider when comparing; the nameplate is not.

The design (big pistons, long throw, air cooling) equates to vibration and high internal stress levels that force either heavy part designs or foster breakage that get much worse as power levels increase. On the other hand, slow operating speeds sometimes help cruise fuel economy when all else is equal.

Do better engines exist- probably... but how do we know? They seldom get a chance to show their stuff for whatever reason, when they go against the inertia of established reasoning.
 
Ooh goody!! ANOTHER Trad/Alt argument! How many times do we need to go back and forth on this?:rolleyes:

Great post Bob...but I think this is going to turn in to another one of those threads...

We all know I've been on both sides of the fence with engines...always entertaining! :)
 
Jabiru?

cjensen said:
Ooh goody!! ANOTHER Trad/Alt argument! How many times do we need to go back and forth on this?:rolleyes:

Great post Bob...but I think this is going to turn in to another one of those threads...

We all know I've been on both sides of the fence with engines...always entertaining! :)
Click to expand...

LOL :D

Hey... while we're stirring the Trad/Alt pots...

I saw on the Jabiru website that they have 5100's in stock now... but no other details. 170/180 hp (depending on which spec you read), 8 cyl. smoothness, lighter installed weight than a Lyco...

But of course... new and unproven... but when has that ever stopped us?!

Which pot does that one go it? :p

DJ
 
darwinian comment...

It's not a crocodile. It's a shark, or a mosquito. Both have been around for about 150 million years without changes (not needed to survive)...:D
 
As time goes on, I think we are seeing that the gear reduction unit is a bigger problem than a complex, high-reving engine. Not only are the Subaru's having PSRU problems, Todd says his Chevy gearbox is going back for work.

Question: Does anybody know of an experimental gearbox with 1000 hrs on it?
 
So, does this mean we have to stop calling them "Lycosaurus", and start using "Lycodile"-----or even better, "Lycodyle"????:rolleyes:
 
Keep it coming

I for one appreciate the banter. I am on the fence Lycodile (clone) Vs Egg.

I trust the opinions of those on this post and hope it can continue.
 
Bugsy said:
I for one appreciate the banter. I am on the fence Lycodile (clone) Vs Egg.

I trust the opinions of those on this post and hope it can continue.
Click to expand...

Trust me, it will continue...it's just been rehashed so many times, with the same things being said over and over again...

Don't get me wrong, I used to participate in these threads regularly, and it is fun...but it's all been discussed in the past threads.

;):)
 
I think the reason people look for alternatives to Lyco is because the engine doesn't look like it's worth five figures.

Lyco: stone-axe simple with manual controls, 1-2 hours to install, >$20K new.

Auto: new engines have more processing power than the Apollo capsules and are so automated that any fool can safely operate one (as is demonstrated on our highways every day), 2-3 *days* to install. ~$6K new.

Basically, it's that people don't like to spend terrifying amounts of money on simple things.
 
Coinneach said:
I think the reason people look for alternatives to Lyco is because the engine doesn't look like it's worth five figures.

Lyco: stone-axe simple with manual controls, 1-2 hours to install, >$20K new.

Auto: new engines have more processing power than the Apollo capsules and are so automated that any fool can safely operate one (as is demonstrated on our highways every day), 2-3 *days* to install. ~$6K new.

Basically, it's that people don't like to spend terrifying amounts of money on simple things.
Click to expand...

If you look at all the legit auto conversions you will see that they are equal or more expensive than a Lycoming when you add cooling system, Propeller and computer. I fly a friend's Glasstar with the NSI Subaru and Whirlwind electric prop. It is very smooth running and has good power but I still don't trust the gearbox. When he was all done he could have had a new Lyclone and Hartzell prop for less money. The only advantage he has over the Lyc is that the prop will go into beta mode and since this airplane is on amphib floats it makes docking really easy. As for me I like the Lycoming on my 7. Don
 
yakdriver said:
If you look at all the legit auto conversions you will see that they are equal or more expensive than a Lycoming when you add cooling system, Propeller and computer.
Click to expand...

I should have been more clear: I wasn't talking about auto conversions, I was talking about airplane engines vs car (as in, not flying) engines. Since the latter are what most people are familiar with, that's where the sticker shock comes in.
 
Coinneach said:
I think the reason people look for alternatives to Lyco is because the engine doesn't look like it's worth five figures.

Basically, it's that people don't like to spend terrifying amounts of money on simple things.
Click to expand...

This pretty well sums it up however equally true is that complete, well developed packages, ready to run the prop are not cheaper these days- only the engine is, due to mass production.

If Lyco experimental clones were $10K, there would be almost no market for alternatives.

It's just a ton of work to get an auto engine conversion working well in an aircraft and you have to charge for your time if you are in that business. What starts out cheap as a long block easily approaches or exceeds that $20K tag for a Lyclone for commercial vendors. Only DIYers can save any hard cash and this is usually not without plenty of time spent working out issues.

For many in this world, this is the essence and the fun of experimental aviation. Bolting a Lyclone onto a powder coated mount from Van's represents no challenge, no interest and no fun to us- kinda like driving a stock, 5L Mustang. Kinda fun but kinda boring too. Really an RV kit with Lyclone power hardly qualifies as experimental, it is as about a sure thing in kit builts as you can get- and that is a good thing for most.

If basic no hassle, bolt it in and fly it is your cup of tea, by all means do so and enjoy that part of aviation. To others who like to dream, design, machine, weld and build their own unique creations, we do these "crazy" things. This is what turns our cranks (pun intended). Until you've done it, you bolt it up guys just can't understand.
 
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Yukon said:
Question: Does anybody know of an experimental gearbox with 1000 hrs on it?
Click to expand...
Not me but John Byrd of Fort Davis, Texas built something interesting. The airplane is Piper Pacer like and has a V Ford or Chevy engine with a belt reduction drive. When I spoke with him about it a few years ago I am pretty sure he said he had over 1,000 hours on the engine/reduction unit. He said he had some trouble early on and ended up adjusting the belt tension.

By the way, John Byrd is remarkable in several ways.
 
I believe the true savings of the auto engine starts with running mogas. We can run mogas with ethanol. I can go to any Autozone or Chevy dealer in the US and get parts for my engine. You don't overhaul your engine, you go out a buy a new one for <$5,000. I have AC and defrost (Probably $5K to $7K cheaper than Lyco based AC). I don't recommend an auto to anyone who doesn't want to experiment. I have enjoyed the education I have gotten. But I don't think any of us are fools for not going Lyco.
Many people say they don't trust auto conversions because of possible failures. I don't trust any engine a 100%.
WARNING:If you don't want to experiment then go buy a Lyco. Don't fall for anybody's "We sell a complete FWF package!" autoconversion pitch. They may sell you the parts and mostly assembled but there is a lot more work to do after you get the parts. I think in 3 to 5 years you will be able to a get a true FWF package but we are not there yet.
 
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For RTRY:

Simple math and physics. It is often said that big pistons, long stroke etc...create heavy parts and high internal stresses.

Stress is caused by inertial force as pistons and other parts are accelerate or slowed. Inertial load or force or in other words the "stresses" increase at the square of speed, but linearly with force. Which means that if you double the mass of the objects you double the force, but if you double the speed or more accurately the rate of acceleration, you quadruple the force.

This why it is true, and has always been true, that lower rpm as a general rule produces the lowest quantum of stress in a reciprocating engine.

About a year ago I looked up the stroke and so forth of the Subies....within a tenth of an inch of the O-320, so with the same distance travelled in each stroke, RPM has a direct comparative relationship to the acceleration forces from pushing and pulling pistons.

Just to correct the previous, factually incorrect post that the benefit of low rpm is better fuel economy at the expense of creating higher stress.

Now, tuning an engine for a very narrow rpm band, and a steady state running environment makes it possible to achieve truly exceptional specific fuel consumption and have very very simply systems. The advancements in engine control for cars deals largely with issues that do not exist in airplanes. We do not have the transitional throttle issues (throttle response), we do not need a 5,000 rpm wide usable power band. Hence no need for variable valve timing, variable intake runners etc. Even with variable ignition, the benefit is not increased power, but rather some reports of increased fuel efficiency in the 5% neighborhood.

A carbed O-320 with mags will beat the best of the alternative engines when speed/fuel are compared. In short they more efficiently convert fuel to moving the airplane. This would be an engine with half the moving parts, and with redundancy in the ignition system, etc.

In addition, the reason that the mechnical systems are desirable is that the failure mode is preferable. Take mags...they mostly fail, if at all, with plenty of advanced warning in terms of gradual drift. A computer generally fails, if it does, as a total failure.

Finally, Lycoming, Continental, Textron, etc...are not incapable of producing a small multivalve high rpm and gearbox. In point of fact those manufacturers are much better at gear reduction than the conversion folks seem to be. It is not a mistake that they haven't gone that route. They are not ignorant, they are not unaware that cheap automotive components are available. They are not unable to manufacture to the same or better tolerances than the car companies (read the mfg specs for a lyc sometime). They have chosen to produce what is necessary for the application and they do a great job of it.

If you want to experiment great. If the perception of smoothness is worth the additional risk, fuel burn, and speed penalty great.

If you want the most simple, tailored to an airplane package which delivers the best available fuel/speed results, and the most widely supported aircraft engine installation for an RV...the answer is the engine the plane was designed for, and the engine which was designed for a plane.
 
n5lp said:
Not me but John Byrd of Fort Davis, Texas built something interesting. The airplane is Piper Pacer like and has a V Ford or Chevy engine with a belt reduction drive. When I spoke with him about it a few years ago I am pretty sure he said he had over 1,000 hours on the engine/reduction unit. He said he had some trouble early on and ended up adjusting the belt tension.

By the way, John Byrd is remarkable in several ways.
Click to expand...

Some RFI belt drives have many thousands of hours on them according to Don Parnham, having been used for gyro training but I think John was asking about experimental gear PSRUs. I'm thinking only a handful have run 1000+ hours without overhaul to date. It takes most of us a very long time to get 1000 hours on an RV. Alt engined drives have not been too popular until about 5-8 years ago so unless people are flying 150- 200 hours a year, I doubt if we'll see too many with a 1000 hours on anytime soon.

Certainly the Ross, NSI, Crossflow and Egg Gen 1 and 2 have had a number of problems. We're hoping that the latest EPI, MPS, Autoflight, Marcotte, RWS, SPG2 and a couple of new ones about to test prove more reliable in the long run.
 
Bud Warren at "Gear Driven" has a PSRU, I think he has about 800 hours on it. I compared the gears he was using in that unit for the 800 hours against new gears he had in stock, absolutely no wear. I have watched the unit run on a test stand, it is very smooth, set up for constant speed prop generally using Chevrolet engines. If I were going to go alternative (which I'm not), I would really have to consider his gear drive. Rumor has it, that he's going to have a firewall forward demo setup at Sun N Fun for an RV10. Bud's at KCXO in Conroe, TX. He's a really nice guy, and his PSRU is impressive. Maybe next time for me.

I have friends that use Subaru's, it way over my head and would just about insure failure for me in my project. I just can't get over the price of the EGG, NSI & other packages, particularly in regard to resale, however, I do understand 350 ci Chevy's. To each their own, those guys are truly pioneers.
 
Absolutely you don't need 4 valve, quad cam engines with VVT, variable intact tract etc. to power our RVs. That is just what we have to work with in lightweight auto designs other than the LS engines like Todd is using. I actually prefer the slightly older generation engines like the EJ22 and EG33 which have shorter strokes and less junk on them for aviation use.

The Lyclone is as simple as you can make it for the intended application and it does the job well. Just doesn't satisfy the needs and wants of all builders.

There always seems to be tremendous interest in these threads and I often wonder why if nobody is flying non-Lyclones? What some of us are doing must just be a whole lot more interesting I'm thinking than a thread on O-360 carb heat. Or maybe it's just the entertainment value?:rolleyes::)

We like the attention anyway.:cool:;)
 
rv6ejguy said:
Absolutely you don't need 4 valve, quad cam engines with VVT, variable intact tract etc. to power our RVs. That is just what we have to work with in lightweight auto designs other than the LS engines like Todd is using. I actually prefer the slightly older generation engines like the EJ22 and EG33 which have shorter strokes and less junk on them for aviation use.

The Lyclone is as simple as you can make it for the intended application and it does the job well. Just doesn't satisfy the needs and wants of all builders.

There always seems to be tremendous interest in these threads and I often wonder why if nobody is flying non-Lyclones? What some of us are doing must just be a whole lot more interesting I'm thinking than a thread on O-360 carb heat. Or maybe it's just the entertainment value?:rolleyes::)

We like the attention anyway.:cool:;)
Click to expand...

I read it for the amusement factor. And because Cap'n Avgas used the word "crocodile". :D I have a boring Superior IO-360 parallel valve engine sitting in a box, waiting to be installed on my -7, so that tells you where I'm at (but it is equipped with dual Lightspeeds, so I'm not totally old-school). OTOH, my neighbor has a -7 with a an H6 Egg. He just finished the gen3 gearbox install. The installation looks cool, and it sounds fabulous. Does that count for anything?

I swapped a slightly warmed-over injected 5.0 engine for the tired 302 in my early Bronco several years ago. Current level of experimentation is with distributorless ignition (though based on Ford parts). Still working the bugs out, tuning-wise. Ironically it's mostly that project which steered me towards a lyclone- two engine toys would be too much.


For many in this world, this is the essence and the fun of experimental aviation. Bolting a Lyclone onto a powder coated mount from Van's represents no challenge, no interest and no fun to us- kinda like driving a stock, 5L Mustang. Kinda fun but kinda boring too. Really an RV kit with Lyclone power hardly qualifies as experimental, it is as about a sure thing in kit builts as you can get- and that is a good thing for most.

If basic no hassle, bolt it in and fly it is your cup of tea, by all means do so and enjoy that part of aviation. To others who like to dream, design, machine, weld and build their own unique creations, we do these "crazy" things. This is what turns our cranks (pun intended). Until you've done it, you bolt it up guys just can't understand.
Click to expand...

I guess that describes me pretty well, except for the understanding part. I get it, even if I'm not doing it. I applaud the inveterate tinkerers among us.
 
Crocoming/Lycogator

Something that no-one seems to have picked up on in Bob's original posting - the fact is that none of the technical innovations, such as 4-valve heads, overhead cams, supercharging etc came out of WW2. Sure, they were all employed as a result of the conflict, but the technologies had been out there since the 1920's at least.

AJS motorcycles : hemi head in 1920, OHC in 1930, supercharged in 1936
Norton motorcyles : OHC in 1927
Indian introduced it's 8-valve twin and 4-valve single racers in 1911 (the 1905 models featured a twistgrip throttle, invented by non other than aviation pioneer, Glenn Curtis )
Harley-Davidson : 8-valve twins in 1916
Cyclone : OHC v-twin in 1913
BMW : OHC twins in 1936, DOHC with supercharger in 1939 - they also had mechanical fuel injection in the 1930's
Moto-Guzzi : DOHC, 4-valve single in 1920

I could go on and on and bore everyone, but I think you get my drift.

Cheers

Martin in Oz
 
Harvey said:
Something that no-one seems to have picked up on in Bob's original posting - the fact is that none of the technical innovations, such as 4-valve heads, overhead cams, supercharging etc came out of WW2.
Martin in Oz
Click to expand...

Dear Martin me ol' ozzie mate, I never said they did. Read my post.
 
Harvey said:
Something that no-one seems to have picked up on in Bob's original posting - the fact is that none of the technical innovations, such as 4-valve heads, overhead cams, supercharging etc came out of WW2. Sure, they were all employed as a result of the conflict, but the technologies had been out there since the 1920's at least.

AJS motorcycles : hemi head in 1920, OHC in 1930, supercharged in 1936
Norton motorcyles : OHC in 1927
Indian introduced it's 8-valve twin and 4-valve single racers in 1911 (the 1905 models featured a twistgrip throttle, invented by non other than aviation pioneer, Glenn Curtis )
Harley-Davidson : 8-valve twins in 1916
Cyclone : OHC v-twin in 1913
BMW : OHC twins in 1936, DOHC with supercharger in 1939 - they also had mechanical fuel injection in the 1930's
Moto-Guzzi : DOHC, 4-valve single in 1920

I could go on and on and bore everyone, but I think you get my drift.

Cheers

Martin in Oz
Click to expand...

And then there's the Rolls Royce R that flew in 1931 with 4 valves, overhead cams, etc. and developed almost 2800HP. And let us not forget the sleeve valve engines of Bristol and Napier. Or for that matter the dual crankshaft 12 piston 6 cylinder 2 stroke diesels from Junkers. Blah, blah, blah. Immensely cool stuff. When I visit the Air & Space museum addition at Dulles and look at the engines I sometimes have to remember to breathe :eek:
For anyone who is interested in the history of aero engine development, "The High-Speed Internal Combustion Engine" by Sir Harry Ricardo is a must-read.
 
I keep waiting for someone to come out with an "Airplane" engine conversion. I want to replace the 52 hp 4 cyl 1.6L NA diesel in my 81 VW pickup with a 40 hp 1 cyl Lyc. (one jug off an O-320) :D
 
CNEJR said:
Bud Warren at "Gear Driven" has a PSRU, I think he has about 800 hours on it. I compared the gears he was using in that unit for the 800 hours against new gears he had in stock, absolutely no wear. I have watched the unit run on a test stand, it is very smooth, set up for constant speed prop generally using Chevrolet engines. If I were going to go alternative (which I'm not), I would really have to consider his gear drive. Rumor has it, that he's going to have a firewall forward demo setup at Sun N Fun for an RV10. Bud's at KCXO in Conroe, TX. He's a really nice guy, and his PSRU is impressive. Maybe next time for me.

I have friends that use Subaru's, it way over my head and would just about insure failure for me in my project. I just can't get over the price of the EGG, NSI & other packages, particularly in regard to resale, however, I do understand 350 ci Chevy's. To each their own, those guys are truly pioneers.
Click to expand...

Bud Warren update:

http://ntsb.gov/ntsb/brief.asp?ev_id=20071106X01740&key=1
 
Yukon said:
Bud Warren update:

http://ntsb.gov/ntsb/brief.asp?ev_id=20071106X01740&key=1
Click to expand...

3 Uninjured.
...
"In a written statement, the pilot/owner stated that a steel-braided fuel line/hose ruptured and subsequently sprayed fuel on the exhaust and ignition wires, which caused intense heat that burned a hole thru the airplane's firewall."

Wow, that could have been much worse. Any idea what brand of braided fuel line he would've been using?
 
Don't you love the Experimental Catagory?

rv6ejguy said:
The Lyclone is as simple as you can make it for the intended application and it does the job well. Just doesn't satisfy the needs and wants of all builders.
Click to expand...

That is why the Experimentals catagory is great. Everybody can do what they want "for educational purposes"

Coinneach said:
Lyco: stone-axe simple with manual controls, 1-2 hours to install, >$20K new.

Auto: new engines have more processing power than the Apollo capsules and are so automated that any fool can safely operate one (as is demonstrated on our highways every day), 2-3 *days* to install. ~$6K new.

Basically, it's that people don't like to spend terrifying amounts of money on simple things.
Click to expand...

These are the prices because these are what people are willing to spend. Supply and Demand. The auto companies would charge you $20K/engine if they knew they could get it and still keep market share. People are willing to spend $20K+ for a Lycoming (and clone) for lots of reasons, both real and perceived.
 
Why Subaru? Rymes with LSU

Is smoother than Lycoming due to smaller cylinders, 7 main bearings, less displacement.

Doesn't drip oil due to better clearances and block doesn't expand/contract as much.

The Subaru has a great heater and defroster combo for cold weather climes.

Can use either 93 auto fuel vs 100 leaded. Obviously a real advantage overseas where 100 leaded is very expensive or unavailable.

No mixture control, ECM determines proper mixture.

Easier hot starts, with fuel returned to tank the hot starts are easier.

Lycoming makes a great product. Their the leader and using an Alternative/Subaru is not for everyone. I guess that's why we are building an Experimental airplane, to experiment and recreat.

One thing we can all agree one, the number one college team...LSU

Thank goodness the BCS is so endowed with intelligence to pick the perfect teams to play for the NC.

RV 7A H-6
Finishing or almost finished.
Lafayette Louisiana
 
Gearbox ???

Yukon,
I am receiving the Gen 3 this week according to Jan. He shipped the early part of the week.

I weighed flying with my Gen 2 gearbox but I am glad I waited to replace it in my garage. The hangar I am going to is about 35 minutes from my house so I want to have all the loose ends covered. I don't want to haul all my tools around in my car and I know once I get there, I will need something from my house.

The weather here is good and I want to take advantage of it.

RV 7A H-6
Lafayette La.
State motto: If you want to get rid of something, tell everyone it is good to eat and out of season.
 
Good!

ARIZONA STATE MOTTO: It's warm here, so send us all your old people who can't drive.
 
My personal favorite aircraft engine of all time...

Lars said:
And then there's the Rolls Royce R that flew in 1931 with 4 valves, overhead cams, etc. and developed almost 2800HP. And let us not forget the sleeve valve engines of Bristol and Napier. Or for that matter the dual crankshaft 12 piston 6 cylinder 2 stroke diesels from Junkers. Blah, blah, blah. Immensely cool stuff. When I visit the Air & Space museum addition at Dulles and look at the engines I sometimes have to remember to breathe :eek:
For anyone who is interested in the history of aero engine development, "The High-Speed Internal Combustion Engine" by Sir Harry Ricardo is a must-read.
Click to expand...

... and it's a Lycoming!

http://www.prime-mover.org/Engines/Images/lycXR7755.jpg
http://www.prime-mover.org/Engines/Images/xr7755b.jpg
http://www.prime-mover.org/Engines/Images/xr7755a.jpg

7755 cubic inches, 36 cylinders, 5000+ horsepower under test run in 1944, dual sets of camshaft lobes: one set for takeoff power, the other for economy cruise.

Fuel burn 580 gallons/hr at takeoff power.

Oh, and BTW, it's got a prop gearbox since it has coaxial output shafts for counter-rotating props.

I bet its TBO would've been terribly short.

Lots more fascinating engines at http://www.prime-mover.org/Engines/Pictures.html
 
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Cool!

TSwezey said:
I believe the true savings of the auto engine starts with running mogas. We can run mogas with ethanol. I can go to any Autozone or Chevy dealer in the US and get parts for my engine. .
Click to expand...

Cus if you can run mogas with ethanol then so can my Lycoming. Any Lycoming at least if its equipped with an AFP fuel injection system can run the same fuel you can!.....
There is at least one poster that runs 87 mogas in a standard 8.5:1 lyclone...I run 92 just cus I want an inreased saftey margin.

The ethanol argument has nothing to do with the motor itself, its about what happens with dissolved water and will it come out of solution at altitude?

If its a vapour lock argument then simply run two electric pumps (wingroots preferably) on a fuel injected motor and the Lyc is exactly the same as the soob as far as fuel is concerned.

I do agree you can't buy part at Autozone though, Now what about cooling drag? Is that a real issue or not and if so what does that cost in miles per gallon?

If the "true savings" start with the fuel then well 90% of the argument has gone away because there are no savings..

The real savings (if any) are in parts cost.

Do Soobs fly -ve G?....

Frank
IO360
 
Neal@F14 said:
... and it's a Lycoming!

http://www.prime-mover.org/Engines/Images/lycXR7755.jpg
http://www.prime-mover.org/Engines/Images/xr7755b.jpg
http://www.prime-mover.org/Engines/Images/xr7755a.jpg

7755 cubic inches, 36 cylinders, 5000+ horsepower under test run in 1944, dual sets of camshaft lobes: one set for takeoff power, the other for economy cruise.

Fuel burn 580 gallons/hr at takeoff power.

Oh, and BTW, it's got a prop gearbox since it has coaxial output shafts for counter-rotating props.

I bet its TBO would've been terribly short.

Lots more fascinating engines at http://www.prime-mover.org/Engines/Pictures.html
Click to expand...

You forgot to add----------------Liquid Cooled!!!

Neat website, thanks for the link.
 
Let's not for get it never went into production and never incorporated into an operational aircraft.....I'm thinking there were major issues.

Also, counter-rotating props on piston aircraft proved impossible.
 
Yukon said:
Let's not for get it never went into production and never incorporated into an operational aircraft.....I'm thinking there were major issues.

Also, counter-rotating props on piston aircraft proved impossible.
Click to expand...

Not quite impossible: the Avro Shackleton flew with contra rotating props on its Rolls Royce Griffon engines throughout its service life. Which is not to say they were without issues...
 
The latter versions

of the Spitfire had them too.

Can you imagine 2350HP on that little shopping cart trolley wheel at the back!

Frank
 
Sure the Shackelton had counterrotating props. Here is an accounting of the propulsion system I found on Google:

All marks suffered from using the Griffon engines — thirsty for fuel and oil, noisy and temperamental with high-maintenance needs. In 1961 MR.2's engines needed top overhauls every 400 hours and went through a spate of ejecting spark plugs from their cylinderheads. It was not unusual to see an engine changed every day in a unit of 6 aircraft. They were constantly on the cusp of being replaced, but even the potentially beneficial Napier Nomad re-engine didn't quite happen.

The need to replace the Shackleton was first raised in the early 1960s. The arrival of the Hawker-Siddeley Nimrod in 1969 was the end for the Shackleton in most roles but it continued as the main SAR aircraft until 1972. The intention to retire the aircraft was then thwarted by the need for AEW coverage in the North Sea and northern Atlantic following the retirement of the Fairey Gannet. With a new design not due until the late 1970s the existing AN/APS-20 radar was installed in Mk. IIs as an interim measure, the AEW.2, from 1972. The disastrous Nimrod AEW replacement programme dragged on and on and the eventual successor to the Shackleton did not arrive until the RAF finally abandoned the Nimrod AEW and purchased the E-3 Sentry in 1991.

A total of 185 Shackletons were built from 1951 to 1958: around twelve are still believed to be intact, with one still flying. One of the South African aircraft was lost in the 1960s when it flew into the side of the Stetynsberg, a mountain near Worcester in the Cape Province, during very bad weather at night.

Although the joke has been applied to several aircraft, the Shackleton has been described as "a hundred thousand rivets flying in loose formation"[1]

Shackelton, Nimrod, Comet........I rest my case.
 
Yukon said:
Sure the Shackelton had counterrotating props. Here is an accounting of the propulsion system I found on Google:

All marks suffered from using the Griffon engines ? thirsty for fuel and oil, noisy and temperamental with high-maintenance needs. In 1961 MR.2's engines needed top overhauls every 400 hours and went through a spate of ejecting spark plugs from their cylinderheads. It was not unusual to see an engine changed every day in a unit of 6 aircraft. They were constantly on the cusp of being replaced, but even the potentially beneficial Napier Nomad re-engine didn't quite happen.

The need to replace the Shackleton was first raised in the early 1960s. The arrival of the Hawker-Siddeley Nimrod in 1969 was the end for the Shackleton in most roles but it continued as the main SAR aircraft until 1972. The intention to retire the aircraft was then thwarted by the need for AEW coverage in the North Sea and northern Atlantic following the retirement of the Fairey Gannet. With a new design not due until the late 1970s the existing AN/APS-20 radar was installed in Mk. IIs as an interim measure, the AEW.2, from 1972. The disastrous Nimrod AEW replacement programme dragged on and on and the eventual successor to the Shackleton did not arrive until the RAF finally abandoned the Nimrod AEW and purchased the E-3 Sentry in 1991.

A total of 185 Shackletons were built from 1951 to 1958: around twelve are still believed to be intact, with one still flying. One of the South African aircraft was lost in the 1960s when it flew into the side of the Stetynsberg, a mountain near Worcester in the Cape Province, during very bad weather at night.

Although the joke has been applied to several aircraft, the Shackleton has been described as "a hundred thousand rivets flying in loose formation"[1]

Shackelton, Nimrod, Comet........I rest my case.
Click to expand...

Hence my terse comment about issues :cool:

That said, watching "Precious Metal" at Reno is always cool. It may not be competitive in the unlimited gold class, but there's nothing else that sounds like it does. Every year I tell myself I don't need to see the "races" again, but then September rolls around and I find myself planning the next trip over the hill...
 
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