How Good are Modern Auto Engines?
 

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/stor...5--P29C62.aspx

http://www.crateenginedepot.com/stor...-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...

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.

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...
 

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>

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

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.

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.