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How Good are Modern Auto Engines?

R

rv6ejguy

Well Known Member
Hmmmm. Going through my latest Alternative Engines Volume 3 there are a couple interesting articles from Chrysler and GM power train engineers.

The Dodge Viper engines underwent 500 hour WOT dyno tests running the majority of that between torque peak and power peak rpms. Dodge truck engines undergo a similar 800 hour validation with some part throttle and idle running thrown in.

The GM Vortec 4200 straight six DOHC engine tests were staggering in scope compared to the aircraft world. GM built 800 engines for development and testing. 24 engines went on the dyno and all met their 150,000 mile durability target. 5 of these were run WOT for 300,000 miles (let's conservatively say 5000 hours each) and all passed. GM put 4 million test miles on other vehicles validating this engine design alone. Pretty darn impressive!

Cheap powerplants:

http://www.crateenginedepot.com/sto...8-New-Goodwrench-Engine-89017685--P29C62.aspx

http://www.crateenginedepot.com/sto...ured-Goodwrench-Engine-12491864-P2081C62.aspx

The next guy who thinks a modern auto engine can't hack running in an airplane at 75% for 1000 hours needs his head examined.

Now we just need some PSRUs which are this strong...
 
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From my observations, most of the problems with Auto convertions are either PRSU or problems with substandard installation hardware and plumbing. If people could stick to aviation standards for all the plumbing and wiring, and with the right reduction unit, I'd be more than happy to try one.

I keep on thinking about my little 1.8t VW that can put up 200hp without a problem (300 at the crank peak on stock internals), and wonder why no one has done a Watercooled VW install.
 
rv6ejguy said:
Hmmmm.



The GM Vortec 4200 straight six DOHC engine tests were staggering in scope compared to the aircraft world. GM built 800 engines for development and testing. 24 engines went on the dyno and all met their 150,000 mile durability target. 5 of these were run WOT for 300,000 miles (let's conservatively say 5000 hours each) and all passed. GM put 4 million test miles on other vehicles validating this engine design alone. Pretty darn impressive!


The next guy who thinks a modern auto engine can't hack running in an airplane at 75% for 1000 hours needs his head examined.

Now we just need some PSRUs which are this strong...
Click to expand...

WOT.....OK, how much load (horsepower percentage) was placed on these engines while at WOT? If I just floor the engine in my car while in neutral, little HP (work) is produced. Do you know the test parameters and do you think that any of these engines could stand up to driving an aircraft propeller
(through a PRSU) while running at WOT for all these hours?
 
OK, But...

rv6ejguy said:
Hmmmm. Going through my latest Alternative Engines Volume 3 there are a couple interesting articles from Chrysler and GM power train engineers.

The Dodge Viper engines underwent 500 hour WOT dyno tests running the majority of that between torque peak and power peak rpms. Dodge truck engines undergo a similar 800 hour validation with some part throttle and idle running thrown in.

The GM Vortec 4200 straight six DOHC engine tests were staggering in scope compared to the aircraft world. GM built 800 engines for development and testing. 24 engines went on the dyno and all met their 150,000 mile durability target. 5 of these were run WOT for 300,000 miles (let's conservatively say 5000 hours each) and all passed. GM put 4 million test miles on other vehicles validating this engine design alone. Pretty darn impressive!


The next guy who thinks a modern auto engine can't hack running in an airplane at 75% for 1000 hours needs his head examined.

Now we just need some PSRUs which are this strong...
Click to expand...

Ross, it is all in the numbers. I agree that modern automotive engines and systems are absolutely amazing. But the issue here is making it work in an airplane and the numbers are against us. General Motors built a little over nine million vehicles last year (and lost the number one spot to Toyota.) 800 engines for testing isn't a big deal when you are going to sell hundreds of thousands of them. If the airplane market was anything close to that size we would have some great products to choose from. The bad news is that the GA market is shrinking.

Selling 9 million units a year would probably cure the PSRU issue, but that ain't gonna happen. So, it is my IO-360 until someone can show me an integrated package (engine, PSRU, cooling system) that passed a test like GM would have thrown at it, 5000 hours should do it. ;)

John Clark
RV8 N18U "Sunshine"
KSBA
 
Guys, I think Ross was pretty clear. The base engines are excellent. Ross is perfectly aware that we're still far from this level of development in a converted aircraft system. As do I.

BTW, I've been buying and selling those auto engines almost 30 years. The last 19 years I've been running my own store and sold them with a warranty. When I say engines have gotten a lot better, I'm not guessing. I have 19 years of financial statements with a "warranty expense" column. Internal engine repairs have become a financial non issue with later models. It wasn't always that way.

The guys who really watch engine lifespan are the dealers who self-finance low end bad credit sales. "They quit payin' when it quits running" is axiomatic in the tote-the-note business. Today those guys are routinely buying in the 125-150K mileage range and putting them out on a note for another two years.....and a lot of those customers could break a bowling ball in a rubber room <g>
 
captainron said:
WOT.....OK, how much load (horsepower percentage) was placed on these engines while at WOT? If I just floor the engine in my car while in neutral, little HP (work) is produced. Do you know the test parameters and do you think that any of these engines could stand up to driving an aircraft propeller
(through a PRSU) while running at WOT for all these hours?
Click to expand...

I'm not sure you understand. WOT on a dyno means the engine is producing max power at that loaded rpm. The tests are run between torque peak rpm and power peak rpm- just the kind of use you'd see in an aircraft application. This would equate to this engine running at between 190 and 270 hp (70-100% power).

Since the average speed for most vehicles run through their lifetime is 35 to 40 mph, this equates to around 7500 hours running at typical aircraft power settings with no overhaul.

The engine does not care if it is in the car, on a dyno or in an airplane. I did mention that we need better PSRUs to harness this potential in aircraft. My post was about engines.

My point about the 800 engines used for testing and the amount of time spent testing them dwarfs any similar work done by Lycoming or Continental. This is in rebuttal to the years of hearing nonsense that certified aircraft engines were tested to higher standards than automotive engines and that auto engines would not withstand constant high hp/ rpm use.
 
Exactly

The modern car engine is a superb piece of engineering...I wonder with gas going the way it is if GA period is long for this world..If we want to keep flying we may well be putting Toyota's on the nose..

I mean lets face it, unless GM, Ford get their act together and invent some competitive small cars then there won't be an American car industry either!

Frank
 
rv6ejguy said:
I'm not sure you understand. WOT on a dyno means the engine is producing max power at that loaded rpm. The tests are run between torque peak rpm and power peak rpm- just the kind of use you'd see in an aircraft application. This would equate to this engine running at between 190 and 270 hp (70-100% power).

Since the average speed for most vehicles run through their lifetime is 35 to 40 mph, this equates to around 7500 hours running at typical aircraft power settings with no overhaul.

The engine does not care if it is in the car, on a dyno or in an airplane. I did mention that we need better PSRUs to harness this potential in aircraft. My post was about engines.

My point about the 800 engines used for testing and the amount of time spent testing them dwarfs any similar work done by Lycoming or Continental. This is in rebuttal to the years of hearing nonsense that certified aircraft engines were tested to higher standards than automotive engines and that auto engines would not withstand constant high hp/ rpm use.
Click to expand...

That's all I was asking about what the parameters were. I guess I've seen too many snake-oil sales pitches in my time. People can manipulate anything, especially numbers, to make their product shine in someone's eyes.

Anyone old enough to remember the original Sears Die Hard commercials, where they had a battery frozen inside a solid block of ice, and miraculously it would still start a car? Imagine the power that battery had to be able to start an engine at 32 degrees! They sure sold a lot of batteries, though!

Another favorite was when Bosch spark plugs advertised that their ground electrodes were welded at the exact same point in reference to the thread pattern, and thus would insure that the spark plug electrodes would be in the same optimal alignment in each cylinder head location. Some of us were left wondering how Bosch got all the engine manufacturers to thread their cylinder heads exactly the same way for this "optimal" electrode location. Oh well, I guess Champion and AC just didn't care enough to emulate this wonderful German (or Madison Ave.) breakthrough.
 
I think auto engines are constantly improving, improving power, reliability and efficiency, with clean emissions.

The aircraft engines have long since evolved to turbines and jets, and left the piston powered legacy in the dust- Not to say that they don't do the job just fine, it is just that they are not evolving and probably won't due to comparatively low sales.
 
captainron said:
Anyone old enough to remember the original Sears Die Hard commercials, where they had a battery frozen inside a solid block of ice, and miraculously it would still start a car? Imagine the power that battery had to be able to start an engine at 32 degrees! They sure sold a lot of batteries, though!
Click to expand...
Ron,

I do remember those commercials and growing up in Northern Michigan at the time, I can tell you those Die Hards would start an engine down to about -30. Of course, you only had about one try to get it started at those temps. At +20*F, no problem at all.
 
The 24hr of LeMans was this weekend. That's a good torture test for engines - lots of WOT running, changing ambient conditions, engine is packaged in narrow bodywork, not in an open air dyno. Much like putting one in an airplane. These engines still fail, sometimes spectacularly. Puegot clearly had the fastest car this year, but it didn't win. Why? Undersized radiators for one - they spent time in the pit box, cleaning the radiators out. Audi went with a slower but more robust car and won (again). Note that Diesels have won LeMans 3 years in a row now.

If GM can make 5 engines run perfectly on a dyno, well, good for them. I don't care how well it runs in a dyno or a test cell. I want to see it put in service, where the cooling isn't installed perfectly, or some manufacturing flaw isn't detected (do you really think they randomly picked 5 engines off the assembly line and tested those five without any inspection or rework?), where someone uses bad gas that's too low in octane .... you get the idea.

Modern auto engines are good. Ross has mentioned the GM Vortec 4200, someone else the WV/Audi 1.8l and 2.0l turbos ... all good engines. Are they more reliable than Lyclones when installed in aircraft? Dunno, I haven't seen any data that suggests that they are or aren't.

Anyway, yes, the engine may be great, but it's the system that needs to work. This is where the Lycosarus shines - it's simple with respect to its systems. No PSRU. No EI. No water cooling system. No timing advance. No variable valve timing. The engine is most of the system.

Once someone makes an engine and system that works and is shown to be equally or more reliable, it will sell. How many units it sells is a question of how reliable and expensive the system is. If it doesn't work - or worse, it quits working - it doesn't matter howmuch better it should be. Just ask Puegot.

TODR
 
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4 million test miles before release of product plus they put the engine in an off road race truck and won numerous events then they do the Death Valley trailer towing validation then the cold weather tests and cold weather chamber tests I've described elsewhere previously. That's the real world testing part to add to the dyno validation. Tested well indeed- far exceeding the scope of certified aircraft engine testing.

Dyno testing is always a first step in engine development. No sense in putting an engine in a vehicle if the engine does not last on the dyno first.

All the other parts you mention except the PSRU (not GM developed unfortunately) have been proven, tested and validated along with the engine in the most extreme environments engineers can throw at them.

We're awaiting more news on a new PSRU being developed in the NW for 250+ hp engines. It will be properly designed and testing using modern methods.
 
the_other_dougreeves said:
... or some manufacturing flaw isn't detected (do you really think they randomly picked 5 engines off the assembly line and tested those five without any inspection or rework?), where someone uses bad gas that's too low in octane .... you get the idea.
Click to expand...

Of the 800 test engines that Ross quotes earlier, the vast majority are there only to test production processes. They are known as 'off-tool, off process' engines or 'production validation' engines. Most of the effort goes into making sure that the engines that come off the end of the production line will meet the required durability specs - they are not selected or hand-fettled at all.

Some of these tests include 200-odd hours at full power and others are shock cooling tests where the engine is run to max temperature and then flooded with sub-zero coolant before returning to max power again. It makes the 'shock-cooling' that pilots rave about seem comical! In any case the engines must be fully functional and meet specifications at the end of the test. i.e. it they don't just stagger to the finishing line.

The manufacturing and materials technology that is in modern automotive engines is stuff that current piston aero engine manufacturers don't even dream about!

Oh, and active knock control notwithstanding, 'bad gas' (excuse me!) is tested too - I know one major manufacturer tests its ignition calibration by offsetting the timing well past the knock limit and attempting to run for extended periods of time - 10s of minutes without failure - I can't remember the test specification exactly now.
 
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rv6ejguy said:
4 million test miles before release of product plus they put the engine in an off road race truck and won numerous events then they do the Death Valley trailer towing validation then the cold weather tests and cold weather chamber tests I've described elsewhere previously. That's the real world testing part to add to the dyno validation. Tested well indeed- far exceeding the scope of certified aircraft engine testing.
Click to expand...

Here's a "real world" test that probably wasn't included:

1. Run the engine for an hour and shut it down.
2. Let it sit in the vehicle outside for 8 months.
3. Come back and maybe clean some of the bird's nest out of it. (or not)
4. Throw some jumpers across the battery and fire it up.
5. If it starts and sounds "OK", add a couple gallons of fresh gas to revitalize
the old stuff, then go to full power for awhile with maybe a couple of
engine cuts thrown in to refresh the operator's "skills".
6. Shut it down and go home, while making a mental note to maybe change
the oil "next time".
7. Grumble to friends and colleagues that someone should build a "better,
cheaper, higher tech" engine than that old fashioned stuff.
8. Wait a few more months, and repeat.
9. Keep this test going for 20-25 years.
10. Complain bitterly that the engine had to be topped or repaired at only 1200 hours.
 
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the_other_dougreeves said:
The 24hr of LeMans was this weekend. That's a good torture test for engines - lots of WOT running, changing ambient conditions, engine is packaged in narrow bodywork, not in an open air dyno. Much like putting one in an airplane. These engines still fail, sometimes spectacularly. Puegot clearly had the fastest car this year, but it didn't win. Why? Undersized radiators for one - they spent time in the pit box, cleaning the radiators out. Audi went with a slower but more robust car and won (again). Note that Diesels have won LeMans 3 years in a row now.

If GM can make 5 engines run perfectly on a dyno, well, good for them. I don't care how well it runs in a dyno or a test cell. I want to see it put in service, where the cooling isn't installed perfectly, or some manufacturing flaw isn't detected (do you really think they randomly picked 5 engines off the assembly line and tested those five without any inspection or rework?), where someone uses bad gas that's too low in octane .... you get the idea.

Modern auto engines are good. Ross has mentioned the GM Vortec 4200, someone else the WV/Audi 1.8l and 2.0l turbos ... all good engines. Are they more reliable than Lyclones when installed in aircraft? Dunno, I haven't seen any data that suggests that they are or aren't.

Anyway, yes, the engine may be great, but it's the system that needs to work. This is where the Lycosarus shines - it's simple with respect to its systems. No PSRU. No EI. No water cooling system. No timing advance. No variable valve timing. The engine is most of the system.

Once someone makes an engine and system that works and is shown to be equally or more reliable, it will sell. How many units it sells is a question of how reliable and expensive the system is. If it doesn't work - or worse, it quits working - it doesn't matter howmuch better it should be. Just ask Puegot.

TODR
Click to expand...

Be careful with assumptions regarding race results- you need to dig into the rules about what are allowed and what are not.

From Wiki encyclopedia
"The Sigma MC74 powered by a Mazda 12A engine was the first engine and team from outside Western Europe
or the US to finish the entire 24 hours of the 24 Hours of Le Mans, in 1974. Mazda is the only team from outside Western Europe or the United States to have won Le Mans outright and the only non-piston engine ever to win Le Mans, which the company accomplished in 1991 with their four-rotor (2,622 cc/160 cu in- actual displacement, rated by FIA formula at 4,708 cc/287 cu in). The following year, a planned rule change at Le Mans made the Mazda 787B ineligible to race anymore. Mazda is also the most reliable finisher at Le Mans (with the exception of Honda, who has entered only three cars in only one year), with 67% of entries finishing.

The Mazda RX-7 has won more IMSA races in its class than any other model of automobile, with its one hundredth victory on September 2, 1990. Following that, the RX-7 won its class in the IMSA 24 Hours of Daytona race ten years in a row, starting in 1982. The RX7 won the IMSA Grand Touring Under Two Liter (GTU) championship each year from 1980 through 1987, inclusive."
 
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rtry9a said:
Be careful with assumptions regarding race results- you need to dig into the rules about what are allowed and what are not.
...
Mazda is also the most reliable finisher at Le Mans [/B](with the exception of Honda, who has entered only three cars in only one year), with 67% of entries finishing.

The Mazda RX-7 has won more IMSA races in its class than any other model of automobile, with its one hundredth victory on September 2, 1990. ...
Click to expand...
The Mazda rotary has proven to be very reliable in the context of motorsport. Sad that they have been booted from LeMans, but they're active elsewhere. Formula Mazda basically runs spec 13B engines that are sealed during rebuild. Engines often last an entire season.

While this is great with respect to motorsport, an entire season of racing in this kind of formula is about, what, about 200 hours of on-track operation? That's not a great TBO for an airplane engine.

TODR
 
My point is simply that the Rotaries love to run at high power levels, and do so economically for long periods (less efficient at low power levels)- exactly what is needed in aviation. That is a fact often missed in headlines and by the racing community used to seeing only the big names.

Like you said, a race-prepped rotary often is not opened up during the entire season while its piston-powered peers generally carry around spares and are broken down/ overhauled after each race. That great durability, and its light weight, are reasons why the rotary engine has been voted out or penalized in most race categories. The races are mostly rigged by the big money competitors.
 
Naw, I don't buy this stuff. I built and road raced cars for 13 years. My piston engines lasted the whole season without coming apart and we won 7 championships- way more than anyone else in that time period.

Engines had stock rods, blocks, heads, bearings and cranks and were pushing over 200hp/ L specific output in turbocharged form. The long blocks were worth less than $3000 complete and came from the junkyard originally. Yearly rebuilds consisted of a valve reface, mag the crank and rods, new rings and gaskets (about $400-$500). I re-used bearings on my 1407cc engine 4 seasons in a row. We raced some fast Wankels but they were no match for us in hp. I beat one consistently which had a close ratio gearbox (I had stock ratios) and he was in the class above me. Our same class car annihilated all the other Mazdas including the best PP ones.

If people are wearing out piston engines in amateur road racing in less than a season, the wrong people are prepping or driving them.
 
rtry9a said:
Like you said, a race-prepped rotary often is not opened up during the entire season while its piston-powered peers generally carry around spares and are broken down/ overhauled after each race. That great durability, and its light weight, are reasons why the rotary engine has been voted out or penalized in most race categories. The races are mostly rigged by the big money competitors.
Click to expand...
F1 engines are about the highest stressed engines out there short of the Shuttle's main engines. They are designed to last for 2 weekends of qualifying and racing - other engines are used for practice. I sure don't want to fly behind one of those.

Endurance racing engines can be very reliable - within the context of motorsport. The Audi R8's 3.6L twin-turbo V8 made 550 to 600 Hp (The ACO kept shrinking the inlet restrictor) and weighed about 150kg (330lb). The engine never failed in competition (although it did during practice). Audi's standard practice with R8 engines was to build one, put it on the dyno for 8-10 hours, simulating laps at LeMans (i.e., going through rev and load profiles experienced during the laps) and if the engine passed, it got shipped out. What did they cost? If you have to ask....

The 13Bs that are used in Formula Mazda are stock - no race prep is allowed. Engines are sealed at overhaul and must remain sealed.

TODR
 
rv6ejguy said:
Naw, I don't buy this stuff. I built and road raced cars for 13 years. My piston engines lasted the whole season without coming apart and we won 7 championships- way more than anyone else in that time period.

Engines had stock rods, blocks, heads, bearings and cranks and were pushing over 200hp/ L specific output in turbocharged form. The long blocks were worth less than $3000 complete and came from the junkyard originally. Yearly rebuilds consisted of a valve reface, mag the crank and rods, new rings and gaskets (about $400-$500). I re-used bearings on my 1407cc engine 4 seasons in a row. We raced some fast Wankels but they were no match for us in hp. I beat one consistently which had a close ratio gearbox (I had stock ratios) and he was in the class above me. Our same class car annihilated all the other Mazdas including the best PP ones.

If people are wearing out piston engines in amateur road racing in less than a season, the wrong people are prepping or driving them.
Click to expand...

You consider the Daytona and LeMans 24 hour races "amateur road racing"? I think there is a slight difference in our frames of reference,:)

There is no doubt that a prepped reciprocating engine can be built to withstand the considerable internal stresses inherent when the pistons and con rods constantly work against themselves- IF you throw enough money and exotic materials at the problem and expect "frequent" breakdowns. The problem is far worse at high rpms often seen during races. Rotary and turbine engines are very different in that regard, and their durability records reflect that difference.
 
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rtry9a said:
You consider the Daytona and LeMans 24 hour races "amateur road racing"? I think there is a slight difference in our frames of reference,:)

There is no doubt that a prepped reciprocating engine can be built to withstand the considerable internal stresses inherent when the pistons and con rods constantly work against themselves- IF you throw enough money and exotic materials at the problem and expect "frequent" breakdowns. The problem is far worse at high rpms often seen during races. Rotary and turbine engines are very different in that regard, and their durability records reflect that difference.
Click to expand...

I consider SCCA regional and club racing amateur racing and this is the type I was involved in. I don't consider Daytona or LeMans amateur racing.

Wankels had an admirable record racing years ago but are overshadowed today by modern 4 valve piston engines in almost every form of racing- amateur or professional. How many LeMans races have Wankels won in the last decade? Zero. All been piston engines with those pesky reciprocating parts. If Wankels were so superior, they'd be in much more widespread use as the patents have long ago expired. My experience in 13 years of engine building (over 200 engines) and road racing myself was zero rod failures on the engines under my program and this was all with stock rods at rpms as much as 2000 rpm over factory redlines.

Today with multitudes of superior aftermarket rods available, even higher safety margins are available at low cost. Despite your perceptions about piston engines, rod failure is pretty much a non-issue these days. GM's durability tests at high rpm for thousands of hours clearly prove that on production engines.

As one more data point, A friend endurance raced a 4AGE powered Showroom Stock MR2 for about 8 years in Canada and the NW US. The engine accumulated almost 25,000 km of RACE miles, shifting at 7500 rpm. He only changed the timing belt once in that time and never touched the engine.
 
Ross,
The point made was that the Wankels were outlawed at Lemans in 1975 after they won convincingly in 1974. It is sorta difficult to log wins when they are either outlawed or penalized unfairly in most racing classes. IMSA is the exception, and there Mazda has pretty much dominated. Ive always held that the wankel is a much better aircraft motor than automotive, with the possible exception of automotive racing where the engine has to perform under full load for long periods of time and light weight is a virtue.

A minor point- SCAA racing is more about handling than power is it not?

Wankels have never been particularly great at producing low end torque -there the recips ARE the better choice (road driving); the rotary shines at full power (in aircraft apps), particularly in the realm where the recips drop in performance. Im far from negative about reciprocating engines- they have come a long way thru the ages. But they are what they are, the physics of mass and motion do not lie. I value your frequent contributions; Subaru/Egg is my second choice largely from your recommendation and experience.

A quick question: Did you ever look at the Mitsubishi DSM motor? I overhauled one once and was very impressed with the design of the aluminum head- too bad it had an iron block.
 
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rtry9a said:
Ross,
The point made was that the Wankels were outlawed at Lemans in 1975 after they won convincingly in 1974. It is sorta difficult to log wins when they are either outlawed or penalized unfairly in most racing classes.
Click to expand...

EXACTLY.

IIRC, the wankel was penalized by multiplying the displacement by 1.5 or something-------made them run against cars with half again more displacement----and they still won most of the events they were allowed to run in.

Same with the Indy turbine car-----anyone remember that???

http://www.turbinecowboy.com/carstrucksmotorcycles/1967IndyTurbine/photoalbum_view

One of the big pluses touted for racing is that so many technical advances happen in competition.

However, when the competition is outlawed, sure does stifle growth.
 
rv6ejguy said:
I consider SCCA regional and club racing amateur racing and this is the type I was involved in. I don't consider Daytona or LeMans amateur racing.

Wankels had an admirable record racing years ago but are overshadowed today by modern 4 valve piston engines in almost every form of racing- amateur or professional. How many LeMans races have Wankels won in the last decade? Zero. All been piston engines with those pesky reciprocating parts. If Wankels were so superior, they'd be in much more widespread use as the patents have long ago expired.
Click to expand...
The ACO changed the rules on restrictors for rotary engines to essentially make them less competitive after Mazda won LeMans is 1991. In all fairness, it's hard to make competition adjustments to the rotary based on displacement due to its nature. Maybe if a French company made the rotary, the ACO would change the rules back ....

I think Mazda would like the have the rotary return to LeMans, but they are choosing to go forward with their 4-cyl designed with AER. They are successfully racing rotaries in GT cars (e.g., Grand-Am).

On the aviation front, Rotaties are being used in applications where weight and size are critical, e.g., UAVs and self-launching motorgliders. I don't know if they can be competitive with pistons (particularly diesels) on other GA applications where weight and size are less critical and fuel efficiency is more important.

TODR
 
Typically any engine design which wins a lot starts facing weight, altered equivalence factors or inlet/ rev restrictions. One could say the same has afflicted gasoline engines in endurance racing recently. This is a part of racing.

Success may depend more on lobbying or sandbagging to delay rule changes.

The rotary was typically factored at 2X swept volume for years in IMSA and SCCA and that worked well. They traded many wins with Nissan Z cars and their L series engines.

The FIA factored turbos at 1.4 times many years ago. As technology progressed, this had to be changed as turbos dominated everywhere they were allowed and just continued to do so despite factor changes. Finally they were simply outlawed in most forms of racing. The whiners are typically the losers who lacked the vision to develop something different.

I generally agree, Wankels make a better race engine than passenger car engine. On the track, I respected them but never feared them.

I think this whole thread has strayed somewhat. If it makes the Wankel guys happy- yes Wankels are very reliable too and always have been.:)
 
Because they are BANNED

rv6ejguy said:
Wankels had an admirable record racing years ago but are overshadowed today by modern 4 valve piston engines in almost every form of racing- amateur or professional. How many LeMans races have Wankels won in the last decade? Zero. All been piston engines with those pesky reciprocating parts. If Wankels were so superior, they'd be in much more widespread use as the patents have long ago expired. My experience in 13 years of engine building (over 200 engines) and road racing myself was zero rod failures on the engines under my program and this was all with stock rods at rpms as much as 2000 rpm over factory redlines.
Click to expand...

Ross,
I very much concurr with your views on modern piston engines. However I must point out the fact that after Mazda won the Le Mans 24 hour outright in 1991 the rotary engine was banned from future prototype racing. That is why you haven't heard about them lately. There is a great deal of effort made to mannuipulate the rules to various advantage, which is why we have DIESELS winning lately. There are several conversion engines that are attractive both piston and rotary. I have long maintained the rotary makes a better aircraft engine than car engine! The biggest need is for a quality PSRU for a reasonable price. I am supprised that some of the aftermarket transmission designers haven't taken a crack at it. Liability scares off most I'm sure.
Bill Jepson
 
The only competitive roadracing class where the rotary was competitive for a whole season without rebuild were classes that were spec mazda, like formula star mazda.

In formula atlantic, or csports racing (often super Vee Ralts with a body) they are not competitive with the relatively old tech cosworths and 4AGE engines without frequent rebuilds....this is just the nautre of racing.

The swept volume rules sure seemed fair to me, but the reality is that the fuel economy rules have eliminated the rotary where they would otherwise be allowed.
 
rather off topic

Jconard said:
The only competitive roadracing class where the rotary was competitive for a whole season without rebuild were classes that were spec mazda, like formula star mazda.

In formula atlantic, or csports racing (often super Vee Ralts with a body) they are not competitive with the relatively old tech cosworths and 4AGE engines without frequent rebuilds....this is just the nautre of racing.

The swept volume rules sure seemed fair to me, but the reality is that the fuel economy rules have eliminated the rotary where they would otherwise be allowed.
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The current RX-8s have been very successful in racing, but they have been adding weight for "pairity" for the whole season. When something is different and successful it often is killed by rules changes. The indy turbines are a classic example. The first car had some advantages and would have won if a transmission bearing hadn't failed at 495 mile point. The inlet area was cut in half for the next year. Lotus built a VERY innovative chassis for a smaller turbine that was only competitive because of the CHASSIS. They didn't win but the next year inlet areas were reduced to the point that a turbine wouldn't even run. Effectively a ban. Racing is a rules game. Doesn't mean a engine isn't a good one, just that it "fits" the current rules package. We need to keep our focus. That is, is the engine a good one for our use, in an airplane. Rotaries, Subarus, Chevy, Ford, Lycoming I don't care if the package is well engineered. By the way I have never see a rotary Formula C, or C sports racer. When I was building them rotaries weren't allowed period.
Bill Jepson
 
Bill,

I said that the idea of a rotary going a season without a rebuild in a competitive class was B.S. The sedan racing RX-8s are factory backed with handfulls of spare engines in the trailer.

Actually the rotary made inroads into national C Sports racing when the Ralt RT-5 of super vee fame became cheap enough that a few folks bolted a rotary in and a sports racer body on and went racing. Steep learning curve on gearing and reliability. Even though outputs in line with a cosworth or 4AGE are avilable, it is not a very usable engine in all but the hands of the masters. I bellieve the Barfields are the ones, but they have been no cheaper, and no more reliable in racing than the piston engines they replace.

Rotary is a neat engine...let's see what Mistral can actually do with it.
 
GM Not likely a good option

rv6ejguy said:
The GM Vortec 4200 straight six DOHC engine tests were staggering in scope compared to the aircraft world. GM built 800 engines for development and testing. 24 engines went on the dyno and all met their 150,000 mile durability target. 5 of these were run WOT for 300,000 miles (let's conservatively say 5000 hours each) and all passed. GM put 4 million test miles on other vehicles validating this engine design alone. Pretty darn impressive!



Im a little late in the thread, however just wanted to point out that GM's 4200 inline is the worst engine I have ever had the pleasure of driving, and I certainly would not fly behind it. The first engine in our Envoy let go at 17000 km with no warning whatsoever, and the engine in it now, I am afraid to go onto the highway it rattles so bad. The problem with the engine has something to do with the cylinder sleeves breaking away from the forged block. The thing that bothers me is that GM knows there is a problem with this engine (i do believe there are bulletins on it) but yet they advertise the hours and durability above. How many engines did not make the test that we do not hear about?
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jrvssgl said:
rv6ejguy said:
The GM Vortec 4200 straight six DOHC engine tests were staggering in scope compared to the aircraft world. GM built 800 engines for development and testing. 24 engines went on the dyno and all met their 150,000 mile durability target. 5 of these were run WOT for 300,000 miles (let's conservatively say 5000 hours each) and all passed. GM put 4 million test miles on other vehicles validating this engine design alone. Pretty darn impressive!



Im a little late in the thread, however just wanted to point out that GM's 4200 inline is the worst engine I have ever had the pleasure of driving, and I certainly would not fly behind it. The first engine in our Envoy let go at 17000 km with no warning whatsoever, and the engine in it now, I am afraid to go onto the highway it rattles so bad. The problem with the engine has something to do with the cylinder sleeves breaking away from the forged block. The thing that bothers me is that GM knows there is a problem with this engine (i do believe there are bulletins on it) but yet they advertise the hours and durability above. How many engines did not make the test that we do not hear about?
Click to expand...

Always interesting to hear from those using an engine. Thanks for your input. According to the article, all test engines passed the long term, high power validation. I know that GM did not use the proven cast in place method for the sleeves and they bore these in place to 1.5mm wall thickness which nobody else does. Sounds like there might be a process control problem here.

I was not thinking of using this engine in an aircraft, just interested in the development and testing. I'll stick with my Subarus.
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jrvssgl said:
I'm a little late in the thread, however just wanted to point out that GM's 4200 inline is the worst engine I have ever had the pleasure of driving, and I certainly would not fly behind it. The first engine in our Envoy let go at 17000 km with no warning whatsoever, and the engine in it now, I am afraid to go onto the highway it rattles so bad. The problem with the engine has something to do with the cylinder sleeves breaking away from the forged block. The thing that bothers me is that GM knows there is a problem with this engine (i do believe there are bulletins on it) but yet they advertise the hours and durability above. How many engines did not make the test that we do not hear about?
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Are we talking here about a inline GM 4.2L 6 or the V6 4.2L Vortec? Can you guys enlighten me about what years and vehicles used a GM inline 6cyl 4.2L engine? Has it been suggested as the basis for an aircraft conversion engine?

FWIW on the road I drive both a Subaru STi and I've got a 2001 Chevy Blazer with the 4.2L Vortec V6 engine. The Chevy's got about 90K miles now and is absolutely reliable. That's my experience. I'll probably put a new version of this Vortec V6 in my RV-9A (using the Belted Air Power redrive & firewall forward package) when I get to that point.

Dan
RV-9A empenage
Chicago
 
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They are two different engines entirely. The Inline 4.2 was installed in GM Envoys and Chevy Trailblazers since 2002. I haven't heard if it has been suggested that it could be converted to an airplane or not, it looks awfully big for a six cylinder, I would imagine that someone somewhere will try it though.
 
Interestingly the 4.2 Vortec inline garnered Ward's best engine kudos for 2 or 3 years if I remember. I couldn't find any widespread complaints about its reliability on the net at least.

Might be used in a warbird replica but being a straight six, it's a bit heavy. Probably would not fit even in a -10 without some serious cowling mods
 
jrvssgl said:
They are two different engines entirely. The Inline 4.2 was installed in GM Envoys and Chevy Trailblazers since 2002. I haven't heard if it has been suggested that it could be converted to an airplane or not, it looks awfully big for a six cylinder, I would imagine that someone somewhere will try it though.
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The Olds Bravada and GMC Envoy each had the engine - I had one of each for a time. The Bravada had big problems with the ECU in that it shut the engine down twice in the first 5000 miles, once on I-55 near Chicago. GM finally took the vehicle back and I ended up with the Envoy. It did not quit at all in 100,000 miles.

The engine is very smooth and had good power but I just felt it was heavy. The best thing about it was it provided for a short turn radius - I think it was 34 or 35 feet. The V engine models need 42 feet to turn around.

It might work in an airplane but would require a huge amoung of development work.
 
I think the LS series are the real reliable and lightweight engines that are suitable for flying. If you don't need that amount of power I would go with a sube or maybe a honda.
 
I've heard a few reports from some guys using LS crate engines for desert off road racing that they've experienced a a couple seizures. Seems some pistons fitted on the tight side of the clearance scale are a bit too tight for high rpm, high load, high coolant temp abuse. Just something to be aware of. The basics on the LS are very sound.
 
rv6ejguy said:
I've heard a few reports from some guys using LS crate engines for desert off road racing that they've experienced a a couple seizures. Seems some pistons fitted on the tight side of the clearance scale are a bit too tight for high rpm, high load, high coolant temp abuse. Just something to be aware of. The basics on the LS are very sound.
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From what I have experienced so far from running my engine(10 minutes max at a time) is the oil temp has never gotten past 100 degrees, the psru temp hasn't gotten above 110 degrees, I certainly won't need to run it at high RPM to get plenty of power to take off and I need a lot of amperage to get the thing started. Hopefully we will never see stresses like the desert off road engines face!
 
rv6ejguy said:
We're awaiting more news on a new PSRU being developed in the NW for 250+ hp engines. It will be properly designed and testing using modern methods.
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Hey Ross, you mentioned this on the phone, but I forgot to write down which engines it works with. Is this going to be a v8 setup or subaru? If subaru are all of the mounting patterns the same or is the new 3.6l engine different?
 
I wish you naysayers and doubters would please be quiet around our engine and drive, as when we fly 1200 miles from home I would hate it to think it can't make it home. When set up with a proper drive they don't know if they are in a field turning a water pump, or in a boat pulling up to 5 skiers, or in a plane where they think they are in heaven, because as they go up the MAP and load goes down. As for myself and others we are going to continue to enjoy the "ride" flight as ever before.
Jess
 
Driven a Focus lately?

frankh said:
I mean lets face it, unless GM, Ford get their act together and invent some competitive small cars then there won't be an American car industry either.
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And if the American people don't recognize when GM and Ford DO build a competitive small car and continue to be enamoured with Toyota and Honda based off of decade-old prejudices, that American car industry will never have a chance.;)

Roger
-9A slow QB
 
I Have and I'm Rarely Impressed

I think some of the newer American cars have great engines but don't cut it on the rest of the car. Too much bean counting and cost cutting on the chassis, suspension, materials and fit.

I'm sorry to say that most American designed models still fall well short of most Japanese models in long term use. Resale value 5 or 10 or 15 years down the road is usually a good indicator of overall quality. There are only a handful of American vehicles recommended by Consumer Reports based on feedback from consumers who have lived with them.

One good thing is that American cars are WAY better than they were 10-20 years ago. That fact unfortunately is not helping GM at the moment. I hope they can rebound from their serious woes today to show us what they can really do.:) Get that Chevy Volt to market ASAP before the Japanese beat you to it.
 
rrd1_99 said:
And if the American people don't recognize when GM and Ford DO build a competitive small car and continue to be enamoured with Toyota and Honda based off of decade-old prejudices, that American car industry will never have a chance.;)

Roger
-9A slow QB
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This is true, but I'm sorry to say, we who hold these prejudices payed dearly for the priveledge.

I broke in my driver's license in the early 80's when most of the cars in our price range were mid 70 vintage.

For years, I thought it was normal for an automobile to cost 150 or so a month in maintenance and repair.

Then I bought a Toyota and learned first-hand that it is possible to drive a car daily for 14 years and rack up a total repair/ maint. expenditure of less than 2500 bucks.

After I wore that car out, I purchased a Chevy S-10 (under the mistaken impression that quality had found it's way to our shores) and was immediately retuned to the world of 100 dollar a month repair costs.

I'd fly a Subaru, but NEVER a GM or FORD automotive engine. EVER.

Just my opinion, so YMMV of course.
 
I'd gladly fly one...

Mr. Mikey said:
I'd fly a Subaru, but NEVER a GM or FORD automotive engine. EVER.

Just my opinion, so YMMV of course.
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.....either Ford or Chevy. It's the gearbox that's questionable. However, it seems that there's some light at the end of the tunnel.

Regards,
 
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