Auto Engines Aren't Designed to Take Full Power for More Than a Few Minutes...

Discussion in 'Ford' started by rv6ejguy, Jun 28, 2014.

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  1. Jun 28, 2014 #1

    rv6ejguy

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    I've heard something like this for 10 years on aircraft forums from people with no knowledge of automotive engines or modern engineering and validation procedures. If that's your uninformed opinion, watch this whole video: https://www.youtube.com/watch?v=8tEqwXrqzH4

    This sums things up pretty well.

    Anyone here think a Lycoming would survive these tests? Remember this engine puts out over 100hp/Liter specific output, that's the same as a 600hp Lycoming O-360.
     
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  2. Jun 28, 2014 #2

    Topaz

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    I'm a Toyota guy ('02 Tacoma V6 4WD, because I off-road a lot) but, even accounting for marketing FUD, that was danged impressive. Thanks for sharing it. I've seen several members here with very successful V6/V8 auto conversions running on their airplane. Can't argue with success, really.

    Unfortunately, this is the Internet. Mythos and outright fallacies seem to carry the full weight of truth here, often more than the actual truth. I've been fighting the "VW airplane conversions are only good for 40hp" myth for years now, despite the fact that the 65hp VW was pretty much the go-to auto-conversion airplane motor for decades. Can't argue with success there, either, although I've certainly seen plenty try. Much as I hope I'm wrong, I'm sure the next "expert" is right around the corner, ready to "straighten us all out."

    There is a place for auto-conversions. There's a place for certified aircraft engines. Both require serious consideration to install in a homebuilt, albeit for different reasons. What one person chooses for their airplane isn't necessarily the right choice for someone else. So I cannot, for the life of me, understand why everyone gets their undies in such a twist on this subject.
     
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  3. Jun 28, 2014 #3

    BBerson

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    They said 150,000 miles "simulated" on the dyno. What does simulated mean?
    Is that 3000 actual hours on the dyno? (150,000/50mph = 3000hours)
     
  4. Jun 28, 2014 #4

    rv6ejguy

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    No, since the engines spend most of their time at WOT between torque peak and power peak rpm, I'd guess in this case about 1200-1500 hours on the dyno. The cold tests are brutal. Also note that they just keep running the same test loop on the dyno, day after day, including the full power one for one hour with the turbo glowing away the whole time. My guess is this one engine was being beat on the dyno for at least 6 weeks straight. The NASCAR test was pretty much 5000-5700 rpm for 24 hours straight at full boost- 300-360 hp continuously.

    I've been a big fan of turbo engines for 35 years. Atmo engines just can't match the power and torque numbers of smaller turbo engines. I've never had a turbo failure in all that time, including 13 years of building and racing multiple road racing engines.
     
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  5. Jun 28, 2014 #5

    BBerson

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    Any engine can run full power continuous if the cooling system can keep up.
    Apparently this truck has a stock cooling system designed for continuous full power.
    That wasn't always the case.
    My '95 truck could come either with or without an optional heavy duty cooling radiator for towing trailers.
     
  6. Jun 28, 2014 #6

    TFF

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    Add a 72 lbs high inertia dumb bell on the end of the crankshaft; then do all that.
    It is not horsepower that is the limit, it is how the horsepower is required to be delivered. Ferrari on the late 40's and Honda in the late 50's went to small cylinder short stroke engines because they saw a materials limit for big cylinder displacement.

    The point of view depends on where you start. If we had an engine contest for 2000hr TBO and the only two rules were the engine had to be direct drive and it had to turn a 78" three blade Hartzell constant speed prop, Lycoming or Continental will win. Change the rules to bolt on to Sean Tuckers biplane; Lycoming is going to win. Plenty of rules can be made to give advantage to car engines like engine must turn 6000 rpm for TBO where clearly the architecture would be having a IO360 chunking a rod. Lycoming and Continental were car engine builders before WW2 and had plenty of car experience. Everyone tries to do something different you have Ralph Watson - Lycoming Special or Tucker killing Franklin engines so they could only make car engines out of the airplane engines. Engineering is not the solution to problems; it is money. Money will pay for the engineering to fix any problem. If it was easy Porsche would not have bought up all the airplane engines they made. Making a one off or even a 100 off custom auto conversion is great for an intellectual toy, but can you turn out 100,000 engines and bet the farm on that with only as is auto conversions? Probably better than 90% made making to TBO with no problems, minus owner induced stupidity. Who says a Lycoming is porky horsepower Ralph Watson - Lycoming Special There is tons of fodder on both sides. Just like the Tesla car, you can beat convention with a bunch of hard work and lots of money. That is the only thing that it takes.

     
  7. Jun 28, 2014 #7

    rv6ejguy

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    I have seen you post this concern multiple times on HBA. I've been building performance and road racing engines professionally (Mostly Toyota, Nissan and Subaru) for over 30 years now, some with 5 times the stock hp output (yes 5 times). I've used stock water pumps and unmodified coolant passages on every single one and this has never been a problem. It might be on some engines but I've never seen it, certainly not at any hp level we'd use in aircraft ie less than stock hp.

    The auto OEMs have been running WOT durability testing for many decades now. Water cooled engines have never had an internal issue with heat rejection. If the rad was too small or plugged up with crud, that's not the fault of the engine design. That's like saying my darn Lycoming overheated because the top end was full of birds nests.

    My turbo Subaru conversion is plumbed with 3/4 coolant pipes and it cools just fine in a climb to 15,000 feet at 35 inches and 4500 rpm.
     
    Last edited: Jun 28, 2014
  8. Jun 28, 2014 #8

    rv6ejguy

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    My post was intended to finally debunk these nonsense posts by lay people about auto engine durability. For sure hanging a prop on this engine and doing hard aerobatics with it would be foolish just as trying to do what this engine did with an O-360 would be foolish. A good auto conversion needs a proven redrive to handle the prop loads and match the power to weight ratios of a Lycoming to compete. Not rocket science as some have done it even without the engineering might of Ford behind them but the scientific approach would benefit success here rather than the usual LAR approach often employed.

    I am interested to see how Jeff's P-85 works out with the airboat redrive. If it does, the cost of the whole package suddenly becomes very attractive on a per hp basis. One of these: http://www.crateenginedepot.com/LS3...9244097-new-19258770-19301326-P10590C556.aspx and one of these: http://diamondbackairboats.myshopify.com/collections/gear-boxes-belt-drives/products/ox-box or The Ballistic drive Jeff is trying.
     
    Last edited: Jun 28, 2014
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  9. Jun 28, 2014 #9

    Autodidact

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    @ 0:59 the announcer guy says 10 years in 300 hours, and @ 1:10 the engineer says 10 years and 150,000 miles, it looks to me that they ran it 300 hours. I think this is pretty standard for automotive tests; Rolls-Royce tested their V8 engine back when it replaced the old straight six for three hundred hours at WOFT, too, but at the time it was unprecedented for an auto engine IIRC.

    Oops, sorry, it was 500 hours (for the RR), and that was only at 4,500 rpm (still full throttle) -

    http://www.rrec.org.uk/Cars/Rolls-Royce_Motor_Car_Engines/The_V8_Engine_Birth_&_Beginnings.php
     
    Last edited: Jun 28, 2014
  10. Jun 28, 2014 #10

    BBerson

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    I don't think you took the intent of my comment.
    It wasn't a concern, just a comment. I was talking about the truck radiator not the engine. The engine can reject the heat just fine. My experience with loaded trucks is that the radiators on trucks sometimes are not large enough to handle the heat from full continuous power. I wonder if they use stock radiators on the dyno or extra large radiators?

    You must have me confused with someone else, since I don't recall ever commenting about this. My specialty is air cooled. But I will leave you alone, since my comments do seem to bother you.
    Not sure what the point was for posting this thread.
     
  11. Jun 28, 2014 #11

    rv6ejguy

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    They don't use rads on Dynos, usually a cooling loop.

    I already posted what the purpose of posting this thread was.

    As I said, too small a rad is not an engine problem either in a truck or a plane. We don't have problems cooling airplanes as many of us have demonstrated who are flying liquid cooled aircraft so you are right, it's actually not a concern either way so I wondered why you brought it up.
     
  12. Jun 28, 2014 #12

    stol

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    I live the torture test on EVERY flight....... And so far, I LOVE my Ford......
     
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  13. Jun 28, 2014 #13

    rv6ejguy

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    150,000 miles over 300 hours equates to 500 miles per hour...

    150,000 miles over 1500 hours equates to 100 mph. 3750 rpm splits the difference between torque peak and power peak rpm and gives you about 100 mph in the truck.

    I think they are talking about heat and start cycles and accelerated wear compared to normal use. The 150,000 miles is unclear in hours but 300 hours is only 13 days on the dyno 24 hours a day. They mentioned weeks at some point. Not clear for sure but I think most people who watch this video will have new respect on how tough modern auto engines are.
     
  14. Jun 28, 2014 #14

    Autodidact

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    Well, 13 days is two weeks.. But aside from that (I don't think an hour figure is really all that relevant since you could run at a low load and make it last 10,000 hours), I'm in general agreement with you; if the engineers can figure out a way to stress the engine on the dyno to an equivalent of 150,000 miles in 300 hours, then I believe them. Even older slide rule designs would run for two or three hours at close to 2hp/ci in NASCAR with non-roller lifters. Some engines are better than others, some installations are better than others; too many variables to say that this engine will always work and that engine never will.
     
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  15. Jun 28, 2014 #15

    henryk

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    =? \SUZUKI base?\
     
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  16. Jun 28, 2014 #16

    Vipor_GG

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    I've heard the same for years, but I guess no one ever told the engines I abused that they couldn't take it. :D
     
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  17. Jun 28, 2014 #17

    rv6ejguy

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    I read through my old Contact book, Volume 3 this morning. There are multiple articles from GM and Dodge engine development engineers there describing the validation testing new engine designs go through. Just a few quotes;

    Dodge Viper engine, related to valve durability tests- "we got results that easily passed our 500 hour dyno test"

    Dodge Viper engine- "The traditional Chrysler endurance cycle for trucks has been 800 hours...we discarded all the specified light duty and idle test modes and got it down to a 500 hour cycle. It's pretty much a WOT test between peak torque and peak power... We set our targets at passing three 500 hour durability tests, a general 500 hour test, an ECE test (European emissions) and a 100 hour test traditionally done for the exhaust manifold durability"

    GM 4200 Dohc engine- "...five of those were kept on the dyno, running wide open until they hit 300,000 miles"

    GM 3100/ 3400- Covers 80 separate validation tests including Corporate Engine Durability Test of 200 hours, CD-9 test 200 hours, field test 200,000 miles, proving grounds test 50,000 miles...

    A lot of auto engine dyno testing revolves around cyclic testing between TP and PP rpms to simulate actual use and test transmission durability as well. The dyno can be programmed to load the engine and simulate the shifts. One GM test was 1600 hours WOT with the transmission attached, programmed to go up through all the gears, then back down and start over with simulated vehicle mass load on the brake (dyno).

    https://www.youtube.com/watch?v=JSDjzmXFdHc

    https://www.youtube.com/watch?v=LvVK6neQ4q4

    You can see something similar here on an F1 engine where a specific track profile is programmed into the dyno to load the engine: https://www.youtube.com/watch?v=J-62SiWKJzM


    Here you can see the intake/ injector spray on a V10 https://www.youtube.com/watch?v=nX2L-kS7ZL8
     
    Last edited: Jun 28, 2014
  18. Jun 28, 2014 #18

    autoreply

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    Rotax is rumored to be far in development of a 200-300 hp engine, likely V6/V8, PSRU, water-cooled. Not sure whether that's revival of what they shelved or a new design..
     
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  19. Jun 28, 2014 #19

    Vigilant1

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    Yep, there's no doubt that the modern auto engines are reliable (I haven't had any true engine-related problem in my daily drivers for decades--it's the stuff that hangs on them tht has failed: ECUs, power steering pumps, etc). I keep hoping that smaller engines (approx 100-120 HP) will come out that will be great for airplane use, but development seems to be concentrating on improved fuel efficiency (not strictly due to market forces, but due to government mandates), at the expense of greater complexity (variable valve timing, computerized ignitions, etc). This makes good sense for a car, especially as the electronics, servos, sensors, etc get more reliable. But for an airplane, it can be a problem. Ross, all this could be good for you and those in your line of work, building airplane-specific black boxes that make these well-engineered but purpose-built engines suitable for airplanes. And then there's the PSRU thing . . . .
     
  20. Jun 28, 2014 #20

    Kingfisher

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    This I agree is not a true statement. Where I come from there are long stretches of freeway were you can drive as fast as your car can go. I only had a small engine and top speed of 160 km/h or 100mph. So I often drove for many hours with the pedal on or near the floor, and would average at 110 to 120 for the free way part of the drive, just to get where I needed to go. In fact the recommended speed on the freeway in said country is 130km/h, there are even signs for that.

    The point is that even small car engines are designed for these kind of high power settings, probably even more so than V8 engines.
     
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