FooF

question:

will an engine (we're going to say a prelude) that is redlined a few times a day last just as long as an engine that is redlined only a few times a month?

with a honda, i am saying yes it will. we are having this debate because i think hes a total ***** with his prelude.

let me rephrase- (since ppl are having a hard time understanding this else where).

we're not talking driving at redline. we're talking shifting.

sfphinkterMC

why does it matter........drive the car as u like it and dispose of it or rebuild it when its done

BryanS2k

It will last as long as it runs. Meaning any engine will last as long as it doesn't happen to float a valve revving up. Will the valve springs be the same at 15k after being revved to redline everyday compared to a cars valve springs which are never revved to redline? No. Do you expect your car shocks to have the some resistance after going over a bumpy road all its life? I would think not. Much like other things in life valve springs wear out. Weather they wear to a point that they allow a valve to float and contact the piston is another story. The higher in rpm on a daily basis you go the more mileage you put on your valve springs, understand? It's all a chance game. You want to go fast you take that chance. Maybe your friend doesn't want to take that chance. Smart guy if you ask me. Not everyone is a racing/speed freak. Give him a break.

Bryan

CoralDoc

The answer is no.

The more you stress any mechanical device, the shorter its lifetime. However, there are so many variables involved in the life of an engine (any engine) that it's impossible to predict the relative impact of one change (e.g. revving high more often) when comparing two engines. This is because there are variations in build quality and other differences in driver operation than just revving high more frequently.

But all else being equal, the engine that is being shifted at higher revs more often will have a shorter life.

marcucci

Agreed with coraldoc. And engine's life is a function of a lot of things, one of them is RPMs. An engine run at a higher average RPM will last less, since it has seen more revolutions and thus wear. The type of driving is obviously a factor, since running an engine under no load or light load is obviously easier on components than a heavy load.

The H22 in the Prelude is a well-designed motor, you can bounce the thing off of the rev limiter all day long and not expect any problems with it. The motor is good for 200k miles or more under normal driving, I'd expect a good 100k of race miles out of it (assuming proper maintenence) w/o any trouble. Mine saw 35k miles of racing w/o any trouble, and I know of one that's now a track whore that has had similar results.

MY answer to your question, though, is that you might want to worry about your own car. Let your friend do what he wants!

cdelena

[QUOTE]Originally posted by marcucci
[B].. .An engine run at a higher average RPM will last less, since it has seen more revolutions and thus wear.

Triple-H

The answer to any mechanical question is often not an absolute,
we all know the saying "s**t happens".

From my own experience with an internally stock '90 CRX-Si 1.6 16 valve motor with a chip, header, freeflow air intake and a 2.5" low restriction exhaust, I have the following FACTS. The engine red is 6,500, for more than 9 years and about 25 driving schools I have shifted at 7,000 rpms. In addition at there are a few corners where the car has been driven for 10 seconds plus at this constant level. I have never bounced the revs up to that point and I have never missed a shift and forced the revs up there or beyond. The 7,000 rpm shifts have always been an even load, even acceleration up to that point. The car has had a valve adjustment every spring and at 90,000 miles the engine is still strong and compression tests reveals amazingly even pressure in each of the cylinders. The car has always been run with synthetic oil and lots of oil filter changes.

I love Hondas!

marcucci

What would you consider to be optimum?! I would consider "less than optimum" or lugging to be down below the 2000RPM mark for all but WOT. I agree that lugging is bad, but didn't even think it would be an issue. Maybe if someone mistakenly tried to keep RPMs below 2000 in order to increase the life of the motor...

FooF

well yea its obvious that an engine will have more wear, that's not disputed. but will the life be noticeably different? i duno, in hindsight 2-3 times a day is kind of a lot, i shoulda said 2-3 a week. this is kinda similar to the vtec too much thread bleh. thanks for input

Gernby

That's kind of silly. Of course an engine's life is going to be shortened if you increase the wear on it. However, I really don't think that most engines wind up dying of old age. I think that most engines die prematurely due to other circumstances (flooding, broken timing belts, rotten oil seals, car crashes, etc.).

I think it's like a smoker dying in a plane crash. Smoking only shortens a persons life, if they don't get killed by something else first.