Stupid engine question.

[Capt.Crash'n'Burn]

I've noticed a handfull of automotive engines that have been adapted for aircraft use (Porsche, VW, Corvair) and given the high cost of your typical Lycoming or Continental engine, why hasn't this been done more?

If you took a SBC, 4" bore and stroked it to 3.875 (395cid) put on some aluminum heads and a turbo, built it to make peak HP @ 3600 and geared it to the prop 1:1.33, it should make about 350 HP. Yes, it would be a little heavier than a typical aircraft engine, but at a fraction of the price.

Here comes the part where you accuse me of smoking low-grade crack cocaine. ;-)

 

[N801BH]

Been there,,, done that... Got the tee shirt.:wink2:

And, I fly it several times a week.

 

[Capt.Crash'n'Burn]

Been there,,, done that... Got the tee shirt.:wink2:

And, I fly it several times a week.

Is that a Winsor SB in your plane there? What are the specs on it?

Now, if you were willing to spend a little more money, imagine an all aluminum 632 BBC with twin turbos!!

 

[sba55]

Been discussed over and over again. There's lots of reasons why it won't work.

It's failed every time it's been tried, too...

 

[Capt.Crash'n'Burn]

Been discussed over and over again. There's lots of reasons why it won't work.

It's failed every time it's been tried, too...

So N801BH's plane has been photoshoped??

 

[Henning]

I've noticed a handfull of automotive engines that have been adapted for aircraft use (Porsche, VW, Corvair) and given the high cost of your typical Lycoming or Continental engine, why hasn't this been done more?

If you took a SBC, 4" bore and stroked it to 3.875 (395cid) put on some aluminum heads and a turbo, built it to make peak HP @ 3600 and geared it to the prop 1:1.33, it should make about 350 HP. Yes, it would be a little heavier than a typical aircraft engine, but at a fraction of the price.

Here comes the part where you accuse me of smoking low-grade crack cocaine. ;-)

Best configuration I've come up with for a SBC is 4 1/8 bore with a 3 1/4 stroke crank running a 6.3" rod length. You end up with a fat, flat torque band you won't believe. Adding rod length (reducing rod angle) is worth waaay more than increasing stroke. The drop in BSFC is pretty amazing. Thing is, it'll cost me the same to build it for an aircraft (Crower Ultralight billet crank and titanium rods, Cosworth pistons, aluminium block and heads, Isky roller cam and valvetrain kit, turbo's for altitude, fuel injection the reduction drive so I can run 4600 WFO, 4200 HP cruise 3600 cruise and 3200 econo cruise potentially using a Lenco section for the redrive that I can shift into direct drive) as an aircraft engine (though I get more HP, figure 500, and lower cost overhauls) in the 350-400hp range, plus, given the cooling system, I'll still be heavier. The advantage is though that I can hook up an NOS system spraying nitromethane for when I want to "shift into boogie".

 

[Trapper John]

Here comes the part where you accuse me of smoking low-grade crack cocaine. ;-)

No, but you have to consider durability and reliability. And that's where the auto conversions come up short.

 

[Dr. O]

TANSTASFL..

The parts and labor for a totally reliable SB/BB Chevy type motor of 350-500 hp cost as much as a new Lycosaurus.. Search on offshore marine engines, mexican road race engines, etc... About the only advantage is that a field overhaul can be done for a lot less than aircraft...

The guy that can build his own engine has an advantage in labor cost, but not in parts cost... And there is still the issue of can the typical experimental guy build an engine that can be started up and run for 2000 hours at that power level? Only a few can...

denny-o

 

[COFlyBoy]

No, but you have to consider durability and reliability. And that's where the auto conversions come up short.

Yeah, that's where the problem is. You either have to attach a prop to a crank that wasn't designed for it, or you have to design a re-drive which eats into the savings. The other issue is a small block Chevy was made to continuously handle what 75 HP. Asking it to put out 200 HP continuous (assuming 300 max) is a big order.

I've read about several crank failures in the converted corvair engines at the first main bearing due to gyroscopic forces. I took a look at the first main bearing from an O-540. That sucker is huge. It is 4 to 5 inches long, compared to 1.5 inches on a corvair engine. Plus on the Lycoming, the crank has a larger diameter.

I would be willing to fly behind an auto engine if it was converted well, but I don't think they are going to provide the spectacular savings that everyone hopes for.

If I was going to go for it I think I'd do the Mazda rotary engine. You get an engine that can handle the high continuous power, smooth running all in a small package. And I think even with the cooling system they are comparable in weight to the aircraft engine.

 

[Trapper John]

I would be willing to fly behind an auto engine if it was converted well, but I don't think they are going to provide the spectacular savings that everyone hopes for.

It's possible to make a v-type liquid cooled aircraft engine, just look at the old Allison and Rolls Royce V-12s. But they didn't last 2,000 hours either, in spite of having talented engineering teams. And they weren't cheap, either.

If I was going to go for it I think I'd do the Mazda rotary engine. You get an engine that can handle the high continuous power, smooth running all in a small package. And I think even with the cooling system they are comparable in weight to the aircraft engine.

I saw an RV-4(?) at a fly in with a rotary. Dunno how long that would last, it always seemed the rotary's weak point was the rotor seals.

 

[RMCN172RG]

I saw an RV-4(?) at a fly in with a rotary. Dunno how long that would last, it always seemed the rotary's weak point was the rotor seals.

The original Mazda rotary wouldn't last 30,000 miles. But Mazda would come and replace the engine under warranty. That was in the early 70's when my Dad was working on the Wankel project at the GM Tech Center.

Some things I remember from driving the Mazda between tear downs.

Smooth and quiet at idle.

Sounded like a Jet with the muffler off.

9000 RPM for ~30 seconds before it falls apart. I would have loved to have seen that test.

No room in the car back seat and I was not very big back then.

The little car had plenty of get up and go with just two cylinders.

The three cylinder in a Chevelle SS was quoted as being faster than any Corvette.

I don't think they ever solved the seal / reliability issues and computers on a standard IC just made more sense then the Wankel, Stirling or Steam engines they were playing with back then.

 

[nyoung]

There are quite a few experimentals flying about with anything from half VW engines to huge V8s. So it can definitely be done.

IMHO, there are several reasons the conversions haven't made mainstream success.

1. Cooling systems. Most auto engines are water cooled vs air cooled. Plane design thrives on the KISS principle. Adding a water cooling system adds more weight and creates another failure point.

2. RPM range. Aircraft engines are designed to deliver 75% power around ~2500 RPM. Car engines deliver that same HP much higher up the RPM scale. So gear reduction units are required. Again, more weight, changes in CG, and another failure point.

3. Longevity. Aircraft engines are designed to deliver a continuous 75% for their entire lifetime. Most auto engines would suffer a short lifetime if ran continuously at 75%.

4. Long history of failures in a conservative market. I have followed aviation for about 25 years and have seen a ton of engines (auto conversions, diesels, extremely light turbines) proposed, built, and then fail (either mechanically or economically). This does not play well in the conservative aircraft market. Aircraft designers and pilots are reluctant to move outside their proven technologies/comfort zone. IMHO, that's why so many new 172 and 182s are still sold when their SR20 and SR22 counterparts outperform them in every category.

5. Cost. By the time all the special stuff (including a large profit in a low volume market) is added to an auto engine to make it viable in an airplane, the engines suffer price tag bloat. It may still be cheaper than an equivalent HP Lyc or Cont, but it is far from the $4-5k one might pay for a turnkey SBC.

I've noticed a handfull of automotive engines that have been adapted for aircraft use (Porsche, VW, Corvair) and given the high cost of your typical Lycoming or Continental engine, why hasn't this been done more?

If you took a SBC, 4" bore and stroked it to 3.875 (395cid) put on some aluminum heads and a turbo, built it to make peak HP @ 3600 and geared it to the prop 1:1.33, it should make about 350 HP. Yes, it would be a little heavier than a typical aircraft engine, but at a fraction of the price.

Here comes the part where you accuse me of smoking low-grade crack cocaine. ;-)

 

[Capt. Geoffrey Thorpe]

I've noticed a handfull of automotive engines that have been adapted for aircraft use (Porsche, VW, Corvair) and given the high cost of your typical Lycoming or Continental engine, why hasn't this been done more?

If you took a SBC, 4" bore and stroked it to 3.875 (395cid) put on some aluminum heads and a turbo, built it to make peak HP @ 3600 and geared it to the prop 1:1.33, it should make about 350 HP. Yes, it would be a little heavier than a typical aircraft engine, but at a fraction of the price.

Here comes the part where you accuse me of smoking low-grade crack cocaine. ;-)

Been done a lot.

Pietenpol (I'm sure I spelled that wrong) used Ford model T engines - or was it Henderson motorcycle engines? I know both were used in the '20s.

Great Plains (and others) sell VW based engine kits - for their larger engines, they have a unique crank and larger front main bearing. I doubt that there are many actual VW parts in the kit. The big problem with these (as I understand it) is cooling the heads.

Limbach builds engines that are were originally based on the VW design.

Thielert was building certified aircraft engines based on a Mercedes common rail diesel.

Jabiru uses at least some automobile parts in their engines (IIRC they use Chevy pistons).

Rotax sells "snowmobile" engines for aircraft.

Franklin aircraft engines were used in Tucker automobiles.

Lycoming engines were used by Cord, Auburn and Duesenberg.

Pratt and Whitney radial engines were used in tanks.

Just about anything can / has been used on homebuilts.

Hot rodding an engine typically does not improve the expected TBO...

 

[weilke]

1. Cooling systems. Most auto engines are water cooled vs air cooled. Plane design thrives on the KISS principle. Adding a water cooling system adds more weight and creates another failure point.

Rotax 912 engines are liquid cooled and geared, yet they weigh less than a Conti O200.
Yes, it is an additional system, but if I look at my cars, the cooling system has never led to a catastrophic failure. Yes, you may have to replace a leaking pump every once in a while, but that is a failure mode that announces itself with ample warning. If I had to guess, the net effect of liquid cooling on reliability is going to be positive as it does away with some of the catastrophic failures (cylinders coming apart) that plague the air-cooled aviation engines.

For all the reasons stated above, I don't expect automotive conversions to become a factor in general aviation. Yet I am hopeful that someone will develop a larger general aviation engine incorporating the technology advances that make automotive engines as good as they are today.

 

[Dan Thomas]

The Mazda rotary has had cooling issues in aircraft. That engine produces a lot of power in a small package, and so there's a lot of waste heat. The cooling system for the car was designed to handle a low average power output, not full power for five minutes or whatever. And that same issue applies to all auto conversions, even the aircooled ones like the VW that gets real hot and burns its valves.

I put a Soob in a Glastar. I work all day on Lycomings and Continentals. Give me the aircraft engine; it's lighter, much simpler to install, no more expensive once it's all added up, and it can be run at redline or very close to it all day; the auto engine will eventually bite you if you do that to it and so you have to cruise at an RPM well under its max HP RPM and lose a bunch of cruise speed, especially if you use a fixed-pitch prop.

Many, many attempts have been made at auto conversions, and only a few have succeeded to any degree.

Dan

 

[Henning]

Yeah, that's where the problem is. You either have to attach a prop to a crank that wasn't designed for it, or you have to design a re-drive which eats into the savings. The other issue is a small block Chevy was made to continuously handle what 75 HP. Asking it to put out 200 HP continuous (assuming 300 max) is a big order.

Not really. If you're talking about one pulled out of your 1975 Chevy Malibu, yeah, but building a SB Chevy that puts out 325hp continuous for 2000hrs is no great feat. Expensive yes, difficult no. I can put out 1000 hp out of one running it at extremes. The problem with the Wankel is one of efficiency, the BSFCs are high on them. I would use one on nitromethane (the design is very conducive to the long burn times) if I was going for a time to climb record and altitude record setter, but not for a travelling machine.

 

[RMCN172RG]

The is one major problem with todays automotive engines and that is complexity.

Most piston airplane engines need, fuel, air and someone to turn the prop. With just that it will run. Simplicity and reliability.

 

[Henning]

The original Mazda rotary wouldn't last 30,000 miles. But Mazda would come and replace the engine under warranty. That was in the early 70's when my Dad was working on the Wankel project at the GM Tech Center.

Some things I remember from driving the Mazda between tear downs.

Smooth and quiet at idle.

Sounded like a Jet with the muffler off.

9000 RPM for ~30 seconds before it falls apart. I would have loved to have seen that test.

No room in the car back seat and I was not very big back then.

The little car had plenty of get up and go with just two cylinders.

The three cylinder in a Chevelle SS was quoted as being faster than any Corvette.

I don't think they ever solved the seal / reliability issues and computers on a standard IC just made more sense then the Wankel, Stirling or Steam engines they were playing with back then.

2 rotors = 6 cylinders, 3 rotors = 9 cylinders and you equate that with 2 stroke engines, not 4.

 

[Henning]

Rotax 912 engines are liquid cooled and geared, yet they weigh less than a Conti O200.
Yes, it is an additional system, but if I look at my cars, the cooling system has never led to a catastrophic failure. Yes, you may have to replace a leaking pump every once in a while, but that is a failure mode that announces itself with ample warning. If I had to guess, the net effect of liquid cooling on reliability is going to be positive as it does away with some of the catastrophic failures (cylinders coming apart) that plague the air-cooled aviation engines.

For all the reasons stated above, I don't expect automotive conversions to become a factor in general aviation. Yet I am hopeful that someone will develop a larger general aviation engine incorporating the technology advances that make automotive engines as good as they are today.

Ask Continental how liquid cooling worked out. 20 years ago, a bunch of 414s wer retrofitted with the TSIOL liquid cooled engines, see any still around?

 

[RMCN172RG]

2 rotors = 6 cylinders, 3 rotors = 9 cylinders and you equate that with 2 stroke engines, not 4.

So now you're going to get technical and discuss the power phases of the cycle

 

[weilke]

Ask Continental how liquid cooling worked out. 20 years ago, a bunch of 414s wer retrofitted with the TSIOL liquid cooled engines, see any still around?

Continental failing at converting their existing design to liquid cooling is proof that it can't be done ?

 

[Trapper John]

Yet I am hopeful that someone will develop a larger general aviation engine incorporating the technology advances that make automotive engines as good as they are today.

The Lycoming IE2 stuff looks interesting, but I don't have any idea what it costs over a conventional engine and it doesn't look to be retrofittable to existing engines.

 

[weilke]

The Lycoming IE2 stuff looks interesting, but I don't have any idea what it costs over a conventional engine and it doesn't look to be retrofittable to existing engines.

To me, it looks like a conventional Lycoming with some electronic doodads bolted on .

But yes, it's interesting in the sense of some development effort being discernable after 40 years of standstill and regression.

Now if both manufacturers figure out a way to purchase lifters that don't crumble after a while......

 

[Capt.Crash'n'Burn]

Best configuration I've come up with for a SBC is 4 1/8 bore with a 3 1/4 stroke crank running a 6.3" rod length. You end up with a fat, flat torque band you won't believe. Adding rod length (reducing rod angle) is worth waaay more than increasing stroke. The drop in BSFC is pretty amazing.

This is a common myth. Try doing the trig' for the first 15 deg ATDC for different stroke to rod combos and you'll see what I'm saying. There's not much difference.

Thing is, it'll cost me the same to build it for an aircraft (Crower Ultralight billet crank and titanium rods, Cosworth pistons, aluminium block and heads, Isky roller cam and valvetrain kit, turbo's for altitude, fuel injection the reduction drive so I can run 4600 WFO, 4200 HP cruise 3600 cruise and 3200 econo cruise potentially using a Lenco section for the redrive that I can shift into direct drive) as an aircraft engine (though I get more HP, figure 500, and lower cost overhauls) in the 350-400hp range, plus, given the cooling system, I'll still be heavier.

There's no advantage to an ultralight crank in an engine that spends most of its time at a constant RPM. Titanium rods have a MUCH higher failure rate than steel. Why Cosworth Pistons? J&E makes a damn fine product.

The advantage is though that I can hook up an NOS system spraying nitromethane for when I want to "shift into boogie".

"NOS" is Nitrous Oxide, not Nitromethane, 2 different things.

 

[Capt.Crash'n'Burn]

There are quite a few experimentals flying about with anything from half VW engines to huge V8s. So it can definitely be done.

IMHO, there are several reasons the conversions haven't made mainstream success.

1. Cooling systems. Most auto engines are water cooled vs air cooled. Plane design thrives on the KISS principle. Adding a water cooling system adds more weight and creates another failure point.

Cooling was one of the problems I was anticipating. I'll have to talk to N801BH about how he has solved this issue.

2. RPM range. Aircraft engines are designed to deliver 75% power around ~2500 RPM. Car engines deliver that same HP much higher up the RPM scale. So gear reduction units are required. Again, more weight, changes in CG, and another failure point.

3. Longevity. Aircraft engines are designed to deliver a continuous 75% for their entire lifetime. Most auto engines would suffer a short lifetime if ran continuously at 75%.

The belt drive system that N801BH uses looks simple and reliable to me. The longevity of the engine is another issue I'm looking to solve.

4. Long history of failures in a conservative market. I have followed aviation for about 25 years and have seen a ton of engines (auto conversions, diesels, extremely light turbines) proposed, built, and then fail (either mechanically or economically). This does not play well in the conservative aircraft market. Aircraft designers and pilots are reluctant to move outside their proven technologies/comfort zone. IMHO, that's why so many new 172 and 182s are still sold when their SR20 and SR22 counterparts outperform them in every category.

5. Cost. By the time all the special stuff (including a large profit in a low volume market) is added to an auto engine to make it viable in an airplane, the engines suffer price tag bloat. It may still be cheaper than an equivalent HP Lyc or Cont, but it is far from the $4-5k one might pay for a turnkey SBC.

I thing building confidence in an auto engine conversion is key. If you can prove it to be reliable, more people will buy it. The more people that but it, the cheaper it will become.

If this can finally be done, it will ive power to the (airplane) people!!

 

[Henning]

"NOS" is Nitrous Oxide, not Nitromethane, 2 different things.

Nitrous oxide is the oxidizer, the nitromethane is used as the spray/enrichment fuel rather than gasoline since it carries its own oxygen. You can use a lot less nitrous oxide saving you weight per hp in fuel when you get into the upper reaches of atmosphere so you save the weight for your pressure suit when going for a recip engine altitude record. Basically you run a recip engine in rocket mode until it's out of fuel or the prop quits grabbing.

BTW, you use the ultralight crank and titanium rods to save weight. Aircraft are all about saving weight.

 

[Trapper John]

To me, it looks like a conventional Lycoming with some electronic doodads bolted on .

I guess it depends on how much faith you put into their spec/promo sheet. They talk about a completely redesigned accessory case, but ya, you'd pretty much do that anyway if you planned to eliminate the mags...I really doubt the bottom end, the cylinders or the valvetrain are changed substantially, if even at all. Theoretically, if you manage each cylinder, you could boost the compression ratio, but I bet they are hedging, since they don't know what 100LL replacement we're going to end up with.

But yes, it's interesting in the sense of some development effort being discernable after 40 years of standstill and regression.

I think it's good to see some progress. But the handwriting is on the wall - 100LL is going away, so either come up with a way to deal with less forgiving fuels, or go under. Good for Lycoming; I don't know what Continental is doing about that.

Now if both manufacturers figure out a way to purchase lifters that don't crumble after a while......

I find that troubling. Bad lifters, bad cranks and bad cylinders might be tolerable if we were living on the bleeding edge, like Formula One cars, but this is hardly new stuff. It's not like engines are flying off the shelves, there's plenty of time to get it right.

And what makes it worse is Continental's and Lycoming's marketing message over the last 15 or so years that, "You don't care about your wife and kids unless you get a factory zero-timed engine, or at the least a factory overhauled one", while they quietly buy up all the big name overhaulers. A zero-timed engine can have a 3rd run crank and case, just like a field overhaul can. They're just doing that song and dance because the new aircraft engine sales part of the business is in the dumper and they need to boost their share of a declining market. 30 years ago, no one batted an eye at a good field overhaul from a reputable shop, but now the common wisdom is to completely discount the value of a field overhaul from the asking price of an aircraft for sale. Hmmmmm...

 

[N801BH]

Cooling was one of the problems I was anticipating. I'll have to talk to N801BH about how he has solved this issue.



The belt drive system that N801BH uses looks simple and reliable to me. The longevity of the engine is another issue I'm looking to solve.



I thing building confidence in an auto engine conversion is key. If you can prove it to be reliable, more people will buy it. The more people that but it, the cheaper it will become.

If this can finally be done, it will ive power to the (airplane) people!!

My Zenith 801 STOL was a CHALLANGE to cool. Most planes fly at fairly high airspeeds and the pressure from that incoming air is better managed to route through various coolers for shedding heat. Try that with an airframe that cruises at less then 100 mph, stalls at less then 35 mph, and for difficult tuning, it is able to climb at 3000FPM@ 45 mph while the motor is making 300+ HP. Just try to cool that scenerio.

Longevity of the motor is my least worry.. I will go through my usual rant I preach about once a year.

Auto engines in a car do live a conservative life, I will admit to that.

A V-8 in a U-haul, Ryder or any other rental truck lives a hellish life.

1-They are typically undersized for the application.
2-The receive practically NO maintainance.
3-99% of the time they are run wide open, all day long, up hill and down, by people who will go out in the morning, start them up. They don't allow for proper warm up, overload the truck and hit the interstate highway while floorboarding the throttle all day and night, never check the oil level, water level or for that matter tire pressures.

That sir is a hellish existance in my mind... And for some strange reason these same motors are able to go 100's of thousands of miles..
Why??



Now you really want a rough life, look at marine motors. Same engine as in cars, V-8 Fords and Chevy's.

1-Usually run by complete idiots with more money then sense.
2-They sit on the trailer all winter, not properly winterized. Taken to the lake, ocean, river, etc on the first nice day of the year. Dumped off the trailer, fired up and run wide open all day.
3- On days when the water is rough the boat will leap in the air allowing the motor to rev way beyond its designed goal, then slam back into the water loading the motor to an unbelievable strain. Minute after minute, hour after hour, day after day, month after month, year after year.
4- Put away at the end of the season with little to no maintainance.

And surprisingly they last,, year after year.

I am all ears for someone to explain how they can survive that ....

Ps. I am already biased on using auto engines so your reasoning and facts will be highly debated.

Fire away guys and gals.

As a side note... crash and burn. Look at my website and on the second page it gives a link to 2 videos. One is 30 seconds long and altho the video sucks the sound of the V-8 is KOOL !!!!.

The other video is 25 minutes and will explain how the whole plane works, including my cooling system.

Ben
www.haaspowerair.com

 

[Trapper John]

A V-8 in a U-haul, Ryder or any other rental truck lives a hellish life.

1-They are typically undersized for the application.
2-The receive practically NO maintainance.
3-99% of the time they are run wide open, all day long, up hill and down, by people who will go out in the morning, start them up. They don't allow for proper warm up, overload the truck and hit the interstate highway while floorboarding the throttle all day and night, never check the oil level, water level or for that matter tire pressures.

Baloney. 100% power is foot to the floor, and that just ain't happening. I've driven plenty of Ryder's with DT466's and you don't spend even 5% of the time WOT.

If you think you've got the Next Big Thing, good for you, but let's see test cell charts with your wonder-motor swinging a club prop for 2000 hours.

 

[N801BH]

Baloney. 100% power is foot to the floor, and that just ain't happening. I've driven plenty of Ryder's with DT466's and you don't spend even 5% of the time WOT.

If you think you've got the Next Big Thing, good for you, but let's see test cell charts with your wonder-motor swinging a club prop for 2000 hours.

Nice try at changing the specs.

A DT466 International is a inline 6 cyl diesel.. Not a V-8 gas motor ,,so you get no points for that post. t

 

[bigred177]

Let's just throw a Cummins diesel on the front and not have to worry about gear reduction or maintenance for 20 years

 

[Capt.Crash'n'Burn]

Let's just throw a Cummins diesel on the front and not have to worry about gear reduction or maintenance for 20 years

I see someone is channeling the spirit of Hugo Junkers!!!

 

[Henning]

Now you really want a rough life, look at marine motors. Same engine as in cars, V-8 Fords and Chevy's.

1-Usually run by complete idiots with more money then sense.
2-They sit on the trailer all winter, not properly winterized. Taken to the lake, ocean, river, etc on the first nice day of the year. Dumped off the trailer, fired up and run wide open all day.
3- On days when the water is rough the boat will leap in the air allowing the motor to rev way beyond its designed goal, then slam back into the water loading the motor to an unbelievable strain. Minute after minute, hour after hour, day after day, month after month, year after year.
4- Put away at the end of the season with little to no maintainance.

And surprisingly they last,, year after year.

I am all ears for someone to explain how they can survive that ....

The answer is "They don't" not when treated as you describe. How do I know? I used to tow them in by the droves. When treated and maintained properly they last about the same as aircraft engines when operated at the same conservative HP/CI output ratios (ie: 225-275hp 350 ci, 330hp 454 ci0 and they are operated pretty much the same 65%-75% cruise settings. The guys who have the 900hp 496s and are flogging them, they blow up multiple times in a season.

As for the old U Hauls, they had tiny 2 barrel carbs and a governor under them. Unless you pulled the side cover off of the governor and shoved a bottle cap in there, it never saw a developed WOT situation. Those were 330 ci engines developing 150hp. That's less than 1/2hp/ci, that's a continuous duty rating for any engine I have ever seen. In flight school & rental use, a 172 will run over 4000 hrs on its Lycosaurus O-320. The new trucks are either diesels or governed through their chip sets.

 

[Trapper John]

Nice try at changing the specs.

A DT466 International is a inline 6 cyl diesel.. Not a V-8 gas motor ,,so you get no points for that post. t

And it's the most common engine in the rental truck fleet.

BFD. You didn't specify gas. Go rent a U-Haul with a Ford 6.9 Powerstroke. Same deal but smaller truck, no foot to the floor.

What about your test cell reports? No points for you!

 

[Capt.Crash'n'Burn]

Nitrous oxide is the oxidizer, the nitromethane is used as the spray/enrichment fuel rather than gasoline since it carries its own oxygen. You can use a lot less nitrous oxide saving you weight per hp in fuel when you get into the upper reaches of atmosphere so you save the weight for your pressure suit when going for a recip engine altitude record. Basically you run a recip engine in rocket mode until it's out of fuel or the prop quits grabbing.

That sounds like a very good way to burn pistons. How much experience do you have with nitro??

BTW, you use the ultralight crank and titanium rods to save weight. Aircraft are all about saving weight.

The difference between a standard weight crank, and an ultralight is barely 10 pounds. The difference between steel rods and Ti rods is a couple of pounds and a couple thousand dollars.

 

[Henning]

That sounds like a very good way to burn pistons. How much experience do you have with nitro??

A few years of F/A. If you limit the amount of fuel to the same HP value as gasoline, it's not much harder on the pistons, more so on the valves and turbos because it'll still be burning on the way out, but again, if you limit the fuel to the same horsepower, it won't be a significant factor. The real trick will be cooling in the thin atmosphere.

The difference between a standard weight crank, and an ultralight is barely 10 pounds. The difference between steel rods and Ti rods is a couple of pounds and a couple thousand dollars.

That's 12 lbs, that's significant considering the CG arm it's at, unless you're talking a canard aircraft, it's equivalent to over 20lbs + drag on either. If you want an altitude record, that can be significant.

 

[nyoung]

A nearly infinite supply of lake water to cool the engine does a ton of good for these engines.

PS. My ski boat with a 350 Mercruiser still starts/runs/pulls like it did 20 years ago.

Now you really want a rough life, look at marine motors. Same engine as in cars, V-8 Fords and Chevy's.
<snip>
And surprisingly they last,, year after year.
I am all ears for someone to explain how they can survive that ....
www.haaspowerair.com

 

[weilke]

I think it's good to see some progress. But the handwriting is on the wall - 100LL is going away, so either come up with a way to deal with less forgiving fuels, or go under. Good for Lycoming; I don't know what Continental is doing about that.

Conti just came to an agreement with the makers of the SMA diesel engine to license their technology. Don't know how far they will take that before quitely abandoning it.....

30 years ago, no one batted an eye at a good field overhaul from a reputable shop, but now the common wisdom is to completely discount the value of a field overhaul from the asking price of an aircraft for sale. Hmmmmm...

I don't think that this is the case. People may discount a service limits overhaul from 'Bob' over at the grass-strip but any of the known shops has the same effect on price, a factory 'new' engine will command a premium (most of the time those are upgrades at the same time).

 

[Capt.Crash'n'Burn]

Conti just came to an agreement with the makers of the SMA diesel engine to license their technology. Don't know how far they will take that before quitely abandoning it.....




I don't think that this is the case. People may discount a service limits overhaul from 'Bob' over at the grass-strip but any of the known shops has the same effect on price, a factory 'new' engine will command a premium (most of the time those are upgrades at the same time).

These points brought up by Trapper John are the whole reason that I started this thread, If Lycoming manages to achieve a monopoly on gas piston engines, then converted auto engines become somewhat of a necessity. especially for the homebuilt market. Given the availability of all aluminum, large displacement auto engines, it just becomes a matter of developing good radiators and radiator cowlings.

Lycoming and Continental have become stagnant, and it's time for the industry to move forward. I don't see anyone else offering alternatives.

 

[Henning]

The future is not in automotive gasoline engines though, the future is with diesels. BTW, you can already buy a certified BB Chevy propulsion package from Trace, you will have to develop the STC for the instalation though.