Aircraft engines are supposed to be simple..

I think I recall doing the math on my consumption in the old Conti engine. I was getting right at .45 - .46 BSFC. I did a number of runs, and cacl'd the time, fuel real close. Considering the Prius does something like .40 or slightly lower, I think my old lump isn't doing too bad. Not sure what modern stuff would do, but getting lower than what I'm doing is prolly gonna require direct injection, variable valve timing, diff ignition map, and more compression. All things that are contraindicated for reliability.
 
dyno is not what it is using on the road. Car engines use 25-35% power at 55mph. Dyno is a false loading system. The math isn't hard but this will help


A Toyota 4Runner is not a small, aerodynamic car. Besides, who dives 55 MPH? Not me, except when I slow down for school zones of course. ;)

Maybe a better example though would be my 2002 Chevy truck with a 4.8 L engine. It was one of my company trucks when I was still building auto parts stores all over God's creation. And it would pull my 16' bullet nosed trailer, loaded with construction supplies and equipment, back and forth to jobs from OH to GA to TX to SD and all points in between. That tuck rarely saw overdrive on the highway and was regularly driven over the smokey mountains 'twixt Nashville and Chattanooga doing 75 MPH screaming in second gear.

It is approaching 200k miles and at least a third of that has been with the trailer behind it. The engine has no issues whatsoever (nor does the tranny)...great engine, great truck. I have newer vehicles but it's still my preferred daily driver and it still regularly pulls trailers. Now from farm to farm loaded with a skidsteer or a tractor or some such.
 
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I think I recall doing the math on my consumption in the old Conti engine. I was getting right at .45 - .46 BSFC. I did a number of runs, and cacl'd the time, fuel real close. Considering the Prius does something like .40 or slightly lower, I think my old lump isn't doing too bad. Not sure what modern stuff would do, but getting lower than what I'm doing is prolly gonna require direct injection, variable valve timing, diff ignition map, and more compression. All things that are contraindicated for reliability.

If someone made a Lycoming/Continental cylinder with a better combustion chamber then you'd get most of the efficiency benefit that a new car does.
 
...Maybe a better example though would be my 2002 Chevy truck...
a better example would be a light truck engine installed in an i/o boat. Your typical ski boat will run a duty cycle on the engine a lot closer to an airplane than to a car. Put the car engine in a boat and it will need some kind of attention between 1-2K hours. Just like an aircraft engine.
 
Maybe a better example though would be my 2002 Chevy truck with a 4.8 L engine.
It is approaching 200k miles

Chevy S-10 with 4.3 V-6. 231,000 and change and nothing but a water pump replacement. OTOH, after fifteen Michigan winters the body was self-destructing so I sold it.

Today's automotive engines are truly reliable.
 
a better example would be a light truck engine installed in an i/o boat. Your typical ski boat will run a duty cycle on the engine a lot closer to an airplane than to a car. Put the car engine in a boat and it will need some kind of attention between 1-2K hours. Just like an aircraft engine.

But that engine in a boat would be running a lot more than 2300 RPM though and producing a lot more power per CI than my O-470. And that brings us back to my original point.
 
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That automotive engine also weighs about 2x per ci.
 
But that engine in a boat would be running a lot more than 2300 RPM though and producing a lot more power per CI than my O-470. And that brings us back to my original point.

Again, it only does so through the benefit of gear reduction. You'd be amazed at the size of a direct drive marine engine to make 300hp, they are 6' tall monsters with 9" diameter pistons.
 
Again, it only does so through the benefit of gear reduction. You'd be amazed at the size of a direct drive marine engine to make 300hp, they are 6' tall monsters with 9" diameter pistons.

Diesel I assume? Last forever?
 
Diesel I assume? Last forever?

Some, they came in both, and some in multifuel design. Most of them reside in museum pieces these days although there are a couple out there I know in operation, big single and two cylinder engines.
 
Chevy S-10 with 4.3 V-6. 231,000 and change and nothing but a water pump replacement. OTOH, after fifteen Michigan winters the body was self-destructing so I sold it.

Today's automotive engines are truly reliable.

A sample size of 1.

That engine almost needs a head gasket as a tune up item.
 
Aggie Mike is a good one to ask about which automotive engines are good and which ones aren't. I seem to recall talking to him last year at Gaston's and telling him how bulletproof my 4.8L chevy is and him responding that he can't give those engines away because no one ever needs them.

I think we had that conversation...
 
A sample size of 1.

That engine almost needs a head gasket as a tune up item.

2002 Chevy Impala 3.4L with 226,000 miles second owner (Dad bought it new)

Original transmission, never been repaired. 65,000ish mile fluid changes with filter, never serviced by a dealer.

Engine:

Set of spark plugs. (I broke wire doing these so it got a whole new set)
One minor vacuum leak
One water pump
One upper intake manifold gasket
Two belts
All new radiator hoses a while ago

One cheap car to drive. Would it pass California emissions? I doubt it.

Air conditioning works ok, never been serviced.

I've put two darn Delphi fuel pumps in the bloody thing now. Those aren't cheap. New fuel filters each time.
 
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If I had $1 for every time someone said "works great never broke" and I inspected it and found 50 things wrong, I wouldn't have any trouble financing the flying.

My parents just gave me their Camry, as my mom decided to stop driving. You guessed it. 2002 model, 105,000 miles, "never broke, great condition" except the air conditioner kicks off occasionally (probably leaking/low), the coolant isn't under enough pressure, the belt looks like factory original, the idle is rough (factory original spark plugs, probably), it leaks oil and power steering fluid, the suspension in VERY soft (unsafe in mountains), one lug nut is missing, the brakes fade in and out, the tires were all very low (easily fixed), and tire wear suggests a bad tie rod end. They were unaware of all of that except the oil leak 'cause it dripped on the garage floor. And I still haven't inspected engine internals. The spark plug replacement will include a leak down test.

If it won't pass CA emissions, it's not in working order. It's STUPID easy to pass CA emissions, mind-numbingly so in an OBD-II vehicle.
 
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:yeahthat:

There are lots of things wrong with most vehicles on the road. The owners just don't think they're worth fixing unless they're stuck on the side of the road.
 
Neither could Porsche.

It wasn't that porsche or toyota couldn't.....they didn't....... because they were not interested. The numbers were not there so they didn't bother. I've driven toyota trucks and cars for twenty years including lexus. Excellent vechicles, well thought out, drive and function beautifully. Very few problems, will run on and on.
 
It wasn't that porsche or toyota couldn't.....they didn't....... because they were not interested.
Porche must have been interested, since they developed a commercial version of one of its auto engines, and put it on the market as a Mooney engine option.

http://en.wikipedia.org/wiki/Porsche_PFM_3200

Toyota tried for years to package one of its auto engines for aviation (Scaled Composites built the test plane) but eventually decided against it. Kinda indicates they were interested, too.

http://stargazer2006.online.fr/aircraft/pages/lima.htm

Ron Wanttaja
 
Which is exactly what I said. They both looked into it, took a shot at it, realized it was a bad investment and moved on. Either company certainly has the wherewithal to engineer and build excellent aircraft engines if the numbers are right. The porsche engine was originally an aircraft engine which was then used in the VW. In the automobile field they've done exceptionally well. The light aircraft market is a dead item. It's why everyone is flying something fifty- sixty years old and pretending they are just great.
 
It wasn't that porsche or toyota couldn't.....they didn't....... because they were not interested. The numbers were not there so they didn't bother. I've driven toyota trucks and cars for twenty years including lexus. Excellent vechicles, well thought out, drive and function beautifully. Very few problems, will run on and on.

No, I was there when the Toyota project was going on, I talked to them a lot. They were really trying. They had a Revlon Red Aztec with their engine on one side, the IO-540 on the other side. They could never make the fuel specifics the Lycoming did. You just can't beat the efficiency of a large diameter piston operating near detonation.

The Porsche Mooney was delivered to customers with the Porsche engine, there were a couple other planes the PFM (Porsche Flug Motor) and the PFM was not Porsche's first foray into aviation engines as they had also built a small motor that was around 65hp IIRC. Reportedly Porsche had over $75MM in the PFM program and walked away from it.

Just like every plane is compromise in features to optimize for a function, same holds true for engines. Driving constant speed/load propellers requires different dimensions to optimize that constant acceleration/deceleration diving wheels. If you want to maximize your burn below 3400rpm, you really want to have a 5" or bigger diameter piston to take advantage of the burn time. Personally I still prefer the big pistons with a gear and let them turn up to 3400rpm. The GTSIO-520 is actually very well optimized for driving an aircraft. The lower speed engines are handicapped below 2700rpm against detonation at over .5hp/CI. It can be managed, but you have to use some caution.

Thing is there is no new engine science between a 1930s engine and now. The physics of the fuel haven't changed. There have been some metallurgy improvements, and those have found their way to the aircraft industry as well.
We gain efficiency and precision with EFI, but in a mostly steady state environment, that is not that difficult to achieve with current mixture control. It would be nice if they gave me a 4° advance setting I could use when in a low load leaned out cruise, but that's really all the variability I need for efficiency.

Where these systems pay off is in reliability and durability across the industry. With EFI, you know the mixture has always been correct, and if someone was operating for all it's worth, the engine management system can detect and prevent detonation. Engines are always their most efficient at the edge of destruction. It is an edge as well, fine on one side of the cliff, peddling to your death like Wiley Coyote on the other. This is where the electronic management systems gain their great advantage, especially in cars where you are constantly changing load. It can real time manage the engine at the edge for maximum performance and efficiency.

I have nothing against these systems at all, the reliability of the electronic systems now exceeds the reliability of the mechanical. Neither however are failure proof. I don't really see a great efficiency advantage available to a knowledgeable engine operator. I don't think I would have seen a significant difference in my 310.
 
It wasn't that porsche or toyota couldn't.....they didn't....... because they were not interested. The numbers were not there so they didn't bother. I've driven toyota trucks and cars for twenty years including lexus. Excellent vechicles, well thought out, drive and function beautifully. Very few problems, will run on and on.

No one is doubting what they did for autos. Although Toyota/Lexus are about the least exciting vehicles to drive, lol.
 
A sample size of 1.

That engine almost needs a head gasket as a tune up item.

If you think that you either dont know which engine you're talking about, or have only been around ones that were treated really really bad. The 4.3 is one of our favorite motors to put in competition rockcrawlers, because you literally cannot kill them. The engine in the car I'm building right now came out of an ex-competition crawler that was driven by a guy who has a habit of putting the car on it's roof. I once did the math and figured out that motor had run inverted for well over 2 hours cumulatively. His normal procedure was to keep driving the car around on it's side until the lifters ran dry and started to knock. He also once drove it around with such a big air bubble in the cooling system that the temp gauge wasn't registering properly. He couldn't figure out why it would run fine at first, then didn't wanna idle after 20 minutes or so. It was getting so hot the pistons were trying to seize. It's still running strong several years later.

I've put at least 15 of those engines into vehicles that get the living crap kicked out of them every second they are running. I also have a bored/stroked 4.7l version that's pushing 300hp sitting under my bench that came out of our old racer. It regularly got run all day at 230*+ in the desert. I'm putting it in a hot rod.

I seem to recall talking to him last year at Gaston's and telling him how bulletproof my 4.8L chevy is and him responding that he can't give those engines away because no one ever needs them.

The other reason is that the 4.8 is the exact same motor as the 5.3 with a different crank. The back of the block even has 4.8/5.3 cast into it. If someone is gonna buy a new motor, they are gonna go for the bigger one. Makes the 4.8 kinda worthless.

That said, even with how bulletproof both of those motors are in cars, that is exactly the engine I was talking about people trying to get aircraft certified and failing.
 
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If you think that you either dont know which engine you're talking about, or have only been around ones that were treated really really bad. The 4.3 is one of our favorite motors to put in competition rockcrawlers, because you literally cannot kill them. The engine in the car I'm building right now came out of an ex-competition crawler that was driven by a guy who has a habit of putting the car on it's roof. I once did the math and figured out that motor had run inverted for well over 2 hours cumulatively. His normal procedure was to keep driving the car around on it's side until the lifters ran dry and started to knock. He also once drove it around with such a big air bubble in the cooling system that the temp gauge wasn't registering properly. He couldn't figure out why it would run fine at first, then didn't wanna idle after 20 minutes or so. It was getting so hot the pistons were trying to seize. It's still running strong several years later.

I've put at least 15 of those engines into vehicles that get the living crap kicked out of them every second they are running. I also have a bored/stroked 4.7l version that's pushing 300hp sitting under my bench that came out of our old racer. It regularly got run all day at 230*+ in the desert. I'm putting it in a hot rod.



The other reason is that the 4.8 is the exact same motor as the 5.3 with a different crank. The back of the block even has 4.8/5.3 cast into it. If someone is gonna buy a new motor, they are gonna go for the bigger one. Makes the 4.8 kinda worthless.

That said, even with how bulletproof both of those motors are in cars, that is exactly the engine I was talking about people trying to get aircraft certified and failing.

I agree with just about everything you said... Except the last line..

The only person to actively push for the 4.3 V-6 GM motor in a plane was Jess Meyers at Belted Air in Las Vegas.... His market was for experimentals and NOT for certified planes.....

Maybe you can enlighten me on who else was going to develop the 4.3 for certified aircraft use?:dunno::dunno:.....:confused:
 
I agree with just about everything you said... Except the last line..

The only person to actively push for the 4.3 V-6 GM motor in a plane was Jess Meyers at Belted Air in Las Vegas.... His market was for experimentals and NOT for certified planes.....

Maybe you can enlighten me on who else was going to develop the 4.3 for certified aircraft use?:dunno::dunno:.....:confused:

Was it the 4.3 or 3.8 (basically the same 350 Buick with 2 cylinders lopped off, using different crank shafts) that they were using in Indy cars?
 
Was it the 4.3 or 3.8 (basically the same 350 Buick with 2 cylinders lopped off, using different crank shafts) that they were using in Indy cars?


The 3.8's were Buicks version of a racing engine.. It was used in the NASCAR "Busch' series for years and John Menard got it highly developed for Indy car racing.... It was successful there too.. Till the sanctioning body outlawed it...
 
The 3.8's were Buicks version of a racing engine.. It was used in the NASCAR "Busch' series for years and John Menard got it highly developed for Indy car racing.... It was successful there too.. Till the sanctioning body outlawed it...

Did they use the offset pin crank or the unbalanced?
 
The 5.3 is a very good motor overall, although not without its weak spots. The earlier ones has valve seals that were a weaker design, and the early lifters seemed to have issues. It works great for the trucks and for light towing. It definitely is a bit underpowered towing my boat, but it does the job.

In an airplane? It'd be a bit of an anchor out of the box. Aluminum block and heads would get the weight down, but you'd still have issues getting total system weight down to airplane engine levels, especially with the gearbox.
 
I agree with just about everything you said... Except the last line..

The only person to actively push for the 4.3 V-6 GM motor in a plane was Jess Meyers at Belted Air in Las Vegas.... His market was for experimentals and NOT for certified planes.....

Maybe you can enlighten me on who else was going to develop the 4.3 for certified aircraft use?:dunno::dunno:.....:confused:

When I said "both of those engines" I was referring to the 2 engines I had been talking about in the previous paragraph, the 5.3, and 4.8, which are both iron block variants of the LS series motor which quite a few people have tried putting in aircraft.

As for the 4.3 and 3.8, they are completely different animals. The 4.3 is essentially an old school 350 minus 2 cylinders. The 3.8 is completely different. it's a 60* V not 90* for starters.
 
When I said "both of those engines" I was referring to the 2 engines I had been talking about in the previous paragraph, the 5.3, and 4.8, which are both iron block variants of the LS series motor which quite a few people have tried putting in aircraft.

As for the 4.3 and 3.8, they are completely different animals. The 4.3 is essentially an old school 350 minus 2 cylinders. The 3.8 is completely different. it's a 60* V not 90* for starters.

That depends on which 3.8 you're talking about. The original was a 90° block which is why they made the split pin crank for some, and let the others shake. They both started from the V-8 Buick. Of the early GM V-6s, the only one that was 60° was the 2800.
 
When I said "both of those engines" I was referring to the 2 engines I had been talking about in the previous paragraph, the 5.3, and 4.8, which are both iron block variants of the LS series motor which quite a few people have tried putting in aircraft.

As for the 4.3 and 3.8, they are completely different animals. The 4.3 is essentially an old school 350 minus 2 cylinders. The 3.8 is completely different. it's a 60* V not 90* for starters.

HUH......

https://www.google.com/search?q=Joh...penske-mercedes-pc23-stockblocks.html;500;429
search
 
No one is doubting what they did for autos. Although Toyota/Lexus are about the least exciting vehicles to drive, lol.

You drive what you think is exciting to Florida and return. I'll drive the lexus. It is a fantastic, well thought out automobile, quiet, good pickup, corners very well. Our third one since 2000. ES 350. For" excitement " I drive a cayman but I sure ain't driving it to Naples Florida and back. No joy. My last American car was a 92 , 5.0 mustang. It was poorly built and a joke on a back road. Read mr. Hondas and his company's life story. Or the history of Toyota, who porsche called in to help them with quality problems. To think either could not design a light aircraft engine is absurd. It's a dead market. Done!
 
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I've not made it to my destination in the car more times than I've had aviation engine problems. Let's see:

Engine failure due to failed alternator (and running down the battery) x2.
Coolant failure issues x3.
Failure of the distributor
Frozen fuel line.
Fuel pump failure.

and while it's technically not the engine, I've had a couple of clutch/transmission failures over the decades.
 
You drive what you think is exciting to Florida and return. I'll drive the lexus. It is a fantastic, well thought out automobile, quiet, good pickup, corners very well. Our third one since 2000. ES 350. For" excitement " I drive a cayman but I sure ain't driving it to Naples Florida and back. No joy. My last American car was a 92 , 5.0 mustang. It was poorly built and a joke on a back road. Read mr. Hondas and his company's life story. Or the history of Toyota, who porsche called in to help them with quality problems. To think either could not design a light aircraft engine is absurd. It's a dead market. Done!

It was not a dead market issue, the market was just starting to pick up again and they were looking at making a whole plane. They could not get the fuel efficiency with the small pistons to meet spec.
 
That depends on which 3.8 you're talking about. The original was a 90° block which is why they made the split pin crank for some, and let the others shake. They both started from the V-8 Buick. Of the early GM V-6s, the only one that was 60° was the 2800.

Ectually, the 60deg V6 was punched out to 3.4L with a few other sizes in between. I had a 3.4L V6 in my Pontiac Aztruck SUV. I'm sure it was a 60deg block because it has a problem with the pushrod and intake seals and I had to do a top end clean up on it.

I think you're also thinking of the 3.8 90deg block that was mated to the later bell housing pattern it got from the 60deg block spread. It's a weirdo engine. Used in some Cads? Or Olds? Gosh I can't recall.
 
You drive what you think is exciting to Florida and return. I'll drive the lexus. It is a fantastic, well thought out automobile, quiet, good pickup, corners very well. Our third one since 2000. ES 350. For" excitement " I drive a cayman but I sure ain't driving it to Naples Florida and back. No joy. My last American car was a 92 , 5.0 mustang. It was poorly built and a joke on a back road. Read mr. Hondas and his company's life story. Or the history of Toyota, who porsche called in to help them with quality problems. To think either could not design a light aircraft engine is absurd. It's a dead market. Done!

I didn't say it wasn't a decent car, I said it was boring. Just about everything Toyota/Lexus makes is yawn-inspiring as far as design is concerned. They don't want to be too edgy or it might upset grandma, :lol:. Same could be said about buying a Buick. Just because you haven't owned any modern American vehicles isn't as much a statement about their quality as it says about your willingness to give them a chance. Trucks are a bit of a different story, but my 3 Ford F-150's ('90, '98, '08) have been virtually flawless and required nothing but routine maintenance.
 
For what it's worth, I still believe the best option is the diesel-ignition engines. If they can create an engine that achieves 300-350lbs dry weight w/accessories, makes 200-300HP, burns kerosene, and makes TBO's around 2,500 hours or so it'd be a great option for small GA aircraft. Easily sold in non-US countries and uses fuel that is cheaper than AvGas just about everywhere.

I realize that some of these engines exist or are in certification stages (DeltaHawk, etc), but I think the biggest hurdle (outside of initial purchase cost) would be allowing conversions to existing aircraft.
 
For what it's worth, I still believe the best option is the diesel-ignition engines. If they can create an engine that achieves 300-350lbs dry weight w/accessories, makes 200-300HP, burns kerosene, and makes TBO's around 2,500 hours or so it'd be a great option for small GA aircraft. Easily sold in non-US countries and uses fuel that is cheaper than AvGas just about everywhere.

I realize that some of these engines exist or are in certification stages (DeltaHawk, etc), but I think the biggest hurdle (outside of initial purchase cost) would be allowing conversions to existing aircraft.

No one will buy them for retrofit though until they come out with a 350-400 HP unit that the commercial operators can use. You've been able to put a Diesel in a 182 for over a decade, there may be a hand full done.
 
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