Chev V8 sweetness

[John Clark]

Originally Posted by gmcjetpilot

To go down the freeway in a car takes, what, 35 hp to 90 hp? (depends on vehicle weight, drag and grade) Despite the +300 hp rating, these engines (LS1) are designed to see peak HP ratings only intermittently (as you wind out the gears, not for minutes continuously). The gear box/PSRU is another story. Obviously you can get along pretty good on say 50% of peek HP for these V8's. However that is less HP than the continuous or 75% HP a 540 Lyc can give which weighs less. Frankly a Lyc can fly 100% all day as long as CHT and oil temp are with in limits. A Chevy V8 would not last long at 100% power.

I agree with George, automobile engine horsepower ratings have nothing to continuous operation. If you "hot rodded" a Lycoming or Continental by installing very efficient intake, exhaust, and cam timing you could get some very impressive horsepower, for a few minutes. Using the automotive standard, my IO360 at 5.9 liters 'should' make something around 600 horsepower. My Audi A4 has a 110 cubic inch engine and is rated at 180 horsepower (100 horsepower per liter.) But "normal cruise power" is 14 percent.

For a little insight into auto engine conversions look at marine installations. In a boat they tend to run at higher power settings much of the time. As a result, they have wear issues and failures. The plus in a boat is a simple source of cooling, not available in an airplane.

John Clark
RV8 N18U "Sunshine"
KSBA

[rv6ejguy]

Naw you guys, come on. Don't speculate, educate yourselves. Become a member of SAE, buy the test papers for whatever engine you want to know about and see that modern engines are usually put through a series of dynos tests WOT, power peak rpm of at least 400 hours and some up to 1200 hours. Transmission and shifting tests may go up to 1600 hours WOT from torque to power peak rpm continuously. The often quoted 15 to 30 hp example is lame and illogical.

It just ain't true today anymore what you say. Get the facts, don't work on feelings. I just dismantled my EG33D with an estimated 2100 hours on it. No measurable wear on bearings, crank, cams, valve stems, guides, bores, pistons, ring lands etc. Not even .0001.

It is true that we won't cruise at power peak rpm WOT on any aircraft engine at SL for its whole life. As a professional custom engine builder for 30 years, it is my view that most modern auto engines will last just fine at 75% and say 4000-4500 rpm.

It is true that best fuel specifics are not achieved at super high rpm so we try to gear the engine to operate somewhere around torque peak or below for a decent compromise.

So when you show me some facts about why auto engines don't last under typical aviation conditions, I'll listen. I just don't see major wear or sudden failures on the hundreds of Subaru engines flying with probably in excess of 1/4 million flight hours. Maybe you don't realize the numbers of auto engines flying. Just between Don Parnham's conversions, RAF's and Groen's alone, we are talking over 1000 Subarus. They are working just fine, not throwing rods, breaking cranks or wearing out rings. There are many of these going over 1000 hours being run between 4500-5500 rpm continuously.

That being said, ANY reciprocating engine can fail and do and people die from this every year. I can think of a couple Conti and Lycoming failures in the last 4-5 years which killed people. Minimize your risks, give yourselves some options when you plan your flights.

And no, a Lycoming 360 won't even last a few minutes at 600hp. It is not designed for this and does not rev high enough to even achieve this figure naturally aspirated. It would simply melt down anyway without ADI and spray bar water as it does not have the fin area required to dissipate the heat generated at this hp level. The Conti twin turbo 550 I worked on at Reno this year is hard pressed to make this power at 3200 rpm and 60 inches with reworked heads and cam- and last 8 minutes even with ADI and spray bar water.

[gmcjetpilot]

Originally Posted by rv6ejguy

Become a member of SAE, buy the test papers for whatever engine you want to know about and see that modern engines are usually put through a series of dynos tests WOT, power peak rpm of at least 400 hours and some up to 1200 hours.

I have a lot of respect for SAE and have a PE license. I have read many SAE reports and test, but never on an auto engine. I know SAE is instrumental in making HP specs more standardized. However I am not sure about reliability and longevity standard test. No one advertises an X mile engine. 400 hours I can believe that. I know in my parents or grandparents days if you got 100,000 miles out of your car, it was good. Now we expect twice that or more out of our cars.

It just ain't true today anymore what you say. Get the facts, don't work on feelings. I just dismantled my EG33D with an estimated 2100 hours on it. No measurable wear on bearings, crank, cams, valve stems, guides, bores, pistons, ring lands etc. Not even .0001.

That is impressive. I find that incredible and a testament to not only the desgin but you skill in installation, operation and maintence. I love Subies. I had a 1982 4 door GL Subaru for 12 years. I got it used in 1984. I still regret trading it in. How you even you measure one TEN thousands of an inch is amazing; let's call it zero wear. I just have one question, WHY THE HECK DID YOU TEAR IT DOWN? So with 0.0001 wear in 2100 hours, and say max wear is 0.005, TBO should be 10,500 hours!

It is true that we won't cruise at power peak rpm WOT on any aircraft engine at SL for its whole life. As a professional custom engine builder for 30 years, it is my view that most modern auto engines will last just fine at 75% and say 4000-4500 rpm.

Probably true, but talking to a guy who works For GM on their test track, they blow motors all the time when they intentionally abuse them. No man made thing is perfect or indestructible.

It is true that best fuel specifics are not achieved at super high rpm so we try to gear the engine to operate somewhere around torque peak or below for a decent compromise.

Right on.

I just don't see major wear or sudden failures on the hundreds of Subaru engines flying with probably in excess of 1/4 million flight hours. Maybe you don't realize the numbers of auto engines flying.

I do understand and the fleet has been growing. I think you are mixing failure with wear. Not with standing your 2100 hours as good as new, its wear that I am talking about.

Just between Don Parnham's conversions, RAF's and Groen's alone, we are talking over 1000 Subaru's. They are working just fine, not throwing rods, breaking cranks or wearing out rings. There are many of these going over 1000 hours being run between 4500-5500 rpm continuously.

I think you are sensitive about possible catastrophic failure. I am not saying that. In fact with a "transmission" properly designed to isolate the crank from harmonics a car engine in a car or plane should be what we all expect, reliable.

That being said, ANY reciprocating engine can fail and do and people die from this every year. I can think of a couple Conti and Lycoming failures in the last 4-5 years which killed people. Minimize your risks, give yourselves some options when you plan your flights.

That is true. However since data is hard to come by and statistics impossible to calculate or draw conclusions. I find most most alternative engine loss of power/failures/issues have more to do with anything but the CORE ENGINE mechanics (like electronics or belts). Also in general more people run out of fuel by a huge factor over cranks, rods or valve trains failure. Same with Lycs, engines "blowing up real good" are rare. However the Lyc does have the advantage of FARM TRACTOR technology for its ancillary systems, mechanical carb, FI, mags, fuel pump and so on. Alt engines usually have belts, water pumps and need electonics to work. All these can be reliable but just from a statistcal stand point, "If it ain't there to fail it can't fail".

And no, a Lycoming 360 won't even last a few minutes at 600hp. It is not designed for this and does not rev high enough to even achieve this figure naturally aspirated. It would simply melt down anyway without ADI and spray bar water as it does not have the fin area required to dissipate the heat generated at this hp level. The Cont twin turbo 550 I worked on at Reno this year is hard pressed to make this power at 3200 rpm and 60 inches with reworked heads and cam- and last 8 minutes even with ADI and spray bar water.

I hear you, but your are trying to compare apples and oranges. They are both round and sweet, but some people like apple juice and others oranges.

To make HP you need either displacement and/or RPM. The LYC is a 4 cylinder with twice to displacement per BORE than most car engines. The Lyc is an aircraft specific design, air-cooled engine, directly driving a prop at relatively LOW RPM, a torque motor if you will.

There is no way the 360 Lyc can ever make 600 HP EVER, since its Red line RPM is 2,700 rpm's. Over 10% of 2,700 rpm Lyc recommends a tear down. Now I know many racers run +3,200 rpm. That rpm limit does not make a Lyc bad, since over 2,700 rpm prop efficiency goes down. It is just a special purpose direct drive, low RPM aircraft engine.

It's like comparing a COX 0.049 cu-in model airplane engine that turns 15,000 rpm to a ships diesel engine, max turns 102 rpm and 109,000 hp! LINK They both are good and neither can do the job of the other. The application is different. Auto engines are designed or optimized for cars. Airplane engines are optimized for planes. That is a fair statement. I will grant you the auto-engine makes a better plane engine than a plane engine makes a car engine. However the above diesel and 0.278 lbs per hp per hour is good, but only for the largest ships on the sea.

Your points are well taken, each engine is designed to operate for specific applications at specific limits and duty. A Continental at 60 inch boost , will not last. Is that a surprise? However at Reno, what engine's where in the top and winning planes? Lyc? Cont? Falcon? Any car engines in there? If I wanted more power I would get a TIGO-541-D1B or IO-720 (8-cyl) Lyc. 400-450 hp out the box ain't bad. Just more displacement or RPM or both. Still direct dirve and air-cooled, simple and lighter. With a little tweak reliable +500 HP is possible (I am gussing).

[rv6ejguy]

Merely responding to John's post about the 600hp O-360.

I'm fishing for what the skeptics always loosely state as "not taking it". Does this mean a rod out through the side or just bagged out rings in 100 hours? Nobody here ever answers the questions, they just rehash the same misinformation with nary a single fact in evidence.

Again, show me that evidence of high wear rates caused by high rpm or rods outside the case or whatever the allegations are. Plenty of Egg Subes now with 500+ hours, still zero oil consumption, still perfect compression by all accounts I've read. Why should the wear rates be so high? Many of Don Parnham's Sube gyro engines used for training have gone well over 1000 hours along with his drives- over 500 drives with zero failures over 17 years.

Usually when piston engines start to wear, oil consumption goes up, compression goes down and leakdown goes up. Just ain't happening despite the naysayers beliefs. With the superior close tolerances and even temperature control of liquid cooled engines, coupled with far superior lubrication qualities of synthetic oils, wear is very low.

Piston speed and bearing surface speeds are similar (slightly higher) to aircraft engines because of the shorter strokes and smaller crank journals.

SAE is a huge organization these days heavily involved in aerospace industries as well as automotive and numerous other fields. Take a look at their website. This is where development engineers usually publish their papers on new designs, validation and testing methods and results. It is THE source for information on new automotive engine designs and technology.

George, you remain skeptical. Some things are not freely available on the net like Wiki, SAE engine test and development papers are one of them. Gonna have to spend some money to get the straight scoop.

On occasion, engineers are allowed to release details to print or internet journals. Alternative Engines Vols. 1 and 2 have papers from GM powertrain and Chrysler engineers. One of the Sube sites has a copy of the SAE paper on the EJ engine development for example. The info is there should you truly wish to become educated on what modern auto engines are capable of. This is 2007 now, not 1967. Much has changed.

[N941WR]

There are a number of upgrades for auto engines that allow them to run at continuous high power settings. Just ask anyone who has ever rebuilt a marine engine. Some of the auto engines (Chevy, for example) can interchange parts with their marine counterparts. Heck, you can even build up a pair of counter rotating V-8's, if you want.

I, for one, encourage this type of experimentation. Remember, it wasn?t long ago that RV?s were considered basement built death traps.

[gmcjetpilot]

Originally Posted by N941WR

I, for one, encourage this type of experimentation. Remember, it wasn’t long ago that RV’s were considered basement built death traps.

Ha ha ha ha, really? Homebuilts have been around since the 1920's with the Pietenpol Air Camper (and still are). I guess some people think they are still basement built death traps. The Pietenpol, especially the first ones used model-A Ford car engines, which is still the engine favored amongst Pietenpol "purists", are good planes. They are slow low performance planes and the problem gets into high performance. I think auto engines make sense but the performance is not going to be the same. Even a V8 is a blunt thing to hang on the front of a plane, aerodynamic wise, not to mention radiators. In the 1960's BH Pietenpol began to favor converted engines from the Chevy Corvair. (ref wikipedia).

To be fair when Van came out with the RV-3, it was well respected. VanGrunsven won “Best Aerodynamic Detailing” at the 1972 EAA Convention in Oshkosh in 1972 with the public debut of the RV-3. (ref Wikipedia) It followed a long line of other similar proven planes like the Thorpe T-18 and Midget mustang. However your point is experimentation is good, fun and should be encouraged. I agree.

You know, I know and Ross knows the score, but new people may be enticed by a panacea of promises that might not come to fruition for them for many reasons. The NO FREE LUNCH rule applies. If it sounds too good to be true..... Know what you are getting into. Alternative engines are just that, ALTERNATIVES, no better or worse; however that depends on your goals. If experimentation is a goal, the alternative engine is the way to go. If flying is the goal and getting into the air ASAP, stick to the plans.

My negative converse these debates is not anti-alternative engine or meant to stifle experimentation, only educate new-bees to research and get the facts. It's very possible a New-bee will make the next breakthrough in airplanes and engines, teaching us all a thing or three.

The point is the subject is WAY MORE than how rock solid and cool the core of the engine is. Like everything in aircraft design there are interrelated trade-offs and one thing can affect everything. It's the total package not one thing out of context. The context is propelling a plane through the air with least weight, drag, max performance, min cost to buy, ease of installation, maintence and fuel econ. There are trade offs and it depends on the trade offs you want to make. I never said alternative engines are dangerous, however just by going in a path less travelled or making a major mod to an existing airframe the designer did not envision, you may be exposed to discovered risk. It's common sense. With a RV and Lyc the "experimentation" has been done. It's a know quantity. That appeals to some, others not so much.

[JHines]

...My auto conversion will be a Chev 500+ cu. in. big block, aluminum block and heads, 1 carburetor, magneto ignition. I'll run it direct drive (published data says close to 300HP @2750 RPM). Isolating the crank from the prop? Maybe I'll just bolt up a non-lockup torque converter in a salvaged Aluminum Powerglide bellhousing, and put an SAE prop flange and a big ol' thrust bearing on other end. 2 for the price of one new O-320.

[jonbakerok]

I just noticed that you guys were discussing Bud Warren's geared reduction unit. I thought you might be interested in knowing that the demo plane crashed last Thursday on the way to our EAA chapter meeting to make a presentation about auto conversions.

He and two passengers got out of the plane without injury but the plane burned and was a total loss. From what I heard, he noticed high oil temps on climb out in time to make the crash survivable, but other than that we don't know the cause of the failure. In any case, I would think it might affect the availability of the PSRU in the short term.

[rv6ejguy]

Originally Posted by jonbakerok

I just noticed that you guys were discussing Bud Warren's geared reduction unit. I thought you might be interested in knowing that the demo plane crashed last Thursday on the way to our EAA chapter meeting to make a presentation about auto conversions.

He and two passengers got out of the plane without injury but the plane burned and was a total loss. From what I heard, he noticed high oil temps on climb out in time to make the crash survivable, but other than that we don't know the cause of the failure. In any case, I would think it might affect the availability of the PSRU in the short term.

Yes, shame to see Bud down but glad everyone was ok. I'll await the investigation results before saying anything.

One thing I will say, once a conversion accumulates 250 hours, I'm interested. At 500, I'm thinking pretty good, at 1000 I'm impressed, at 2000 I'm sold.

One offs are a drop in the bucket as far as proven flight time goes of the full system package but they may mean something as far as the core engine or redrive type reliability goes cumulatively. I said to one other Subaru enthusiast who was reading a bit more into his perfect reliability at 230 hours than I thought was valid, that his 230 hours and my 200 hours and someone elses 340 hours were small blips and relatively meaningless in the big scheme. When we all get 1000 or 2000 hours, then we can crow about it more.

I do see 1/4 million Sube flight hours with relatively few core failures as validation of the basic suitability of these engines for aviation use. Drives, fuel and cooling system designs are less well validated to date but making progress as information is shared. There are some good and bad designs out there flying. We'll learn from the failures and improve the designs.

I hope Bud continues to develop and fly his parts.

[gmcjetpilot]

Originally Posted by JHines

...My auto conversion will be a Chev 500+ cu. in. big block, aluminum block and heads, 1 carburetor, magneto ignition. I'll run it direct drive (published data says close to 300HP @2750 RPM). Isolating the crank from the prop? Maybe I'll just bolt up a non-lockup torque converter in a salvaged Aluminum Powerglide bellhousing, and put an SAE prop flange and a big ol' thrust bearing on other end. 2 for the price of one new O-320.

That is cool using the power glide and torque converter, YEA! I like that. Hydraulic coupling is awesome. The power glide is bullet proof.

Stupid questions:

Will you use the gearing two fwd gears in flight (takeoff/climb & cruise)?
(you will need at least one gear ratio other than 1:1 right)

Will the transmission case or tail-housing take prop loads?

The power glide will give a nice aerodynamic nose but how about CG and weight? (long assembly for a plane)

"put an SAE prop flange and a big ol' thrust bearing on other end"
(Don't forget about gyroscopic loads which are large.)

Have you considered a separate prop hub/bearing supported by airframe driven with a short drive shaft? (ie no load on transmission)

Has any one done this before?

Post pictures, please. George

PS sorry to hear about the Wheeler but no injuries makes me happy. Hope they can figure out what went wrong to improve the breed.