Engine failure questions

[ADL]

Hello,
I'm trying to learn about engines and performance levels. I think I'm just starting to get to a point where I need to be smarter about making "safe" horsepower and torque.

What exactly causes an engine to fail ("blow up")? I try to read all I can here on the forums and I understand (kind of) that heat, psi, rpms, etc.. contribute to an engine failure.
From reading, it seems there are "rule of thumb" limits for make/model/year cars and engines (stock) such as "700whp is limit for GT500 5.4L stock internals" (I'm not stating this as fact. Just an example statement).

Obviously, I'm not an engineer. But it seems like there would be some good engineering data and formulas that would make pretty good estimations on engines/component's failure points.

I know folks on this forum have a lot of knowledge and experience. Thanks for any info/comments.

 

[Booky]

Hello,
I'm trying to learn about engines and performance levels. I think I'm just starting to get to a point where I need to be smarter about making "safe" horsepower and torque.

What exactly causes an engine to fail ("blow up")? I try to read all I can here on the forums and I understand (kind of) that heat, psi, rpms, etc.. contribute to an engine failure.
From reading, it seems there are "rule of thumb" limits for make/model/year cars and engines (stock) such as "700whp is limit for GT500 5.4L stock internals" (I'm not stating this as fact. Just an example statement).

Obviously, I'm not an engineer. But it seems like there would be some good engineering data and formulas that would make pretty good estimations on engines/component's failure points.

I know folks on this forum have a lot of knowledge and experience. Thanks for any info/comments.

If you run good fuel and a slightly conservative custom dyno tune from an experienced tuner, you should be pretty safe.

JMO

 

[GT500RedStripe]

1. Avoid is over-spinning.
2. Have a great tuner
3. Good fuel.

I made 842 on stock motor with no issues.

 

[nxhappy]

lots and lots of factors. a good tune is needed. aka somebody that knows what the hell they are doing. IATs need to be low. so a dual fan HE, large IC tank, and 170 Tstat are a MUST if you have any aftermarket parts. Also, fuel is a huge issue. If you are in a state where only 91 octane is available, you cannot push the car as "hard" ...aka high boost or advanced timing. Unless of course you have meth or use torco. The higher the octane the better. This is because the motor is less prone to "pre ignition" or "knock". It's really not this simple but the best thing you can do is talk to your tuner. Rule of thumb: pump gas you want to stay 18 pounds or less on the boost. keep the timing conservative. you start going crazy on the timing, you risk the motor. Also target AFR should be 11.0-11.7 . If you are over 12.0 air to fuel ratio your motor is lean (on a boosted motor). also- do NOT rev this motor too high. keep you shifts around 6200 or less. You take it over 6500 you are rolling the dice. bottom line ....listen to your tuner, get someone that works with GT500s, and use high octane if possible.

 

[1 Alibi 2]

Tune, rpm's, fuel.

 

[GT Premi]

^^What they said. From what I've been reading over the years, with a good tune, good fuel and spark delivery, and conservative revs, a stock GT500 engine can handle 1000HP all day. That said, I don't know if there's a such thing as a "bad" tune on these engines. They can certainly take one hell of a beating and keep on ticking. Of all the years I've been "into" the GT500, I can count on two fingers the instances of a blown engine, and one of those was because of a faulty, secondhand, aftermarket fuel injector. (And even that one was still drivable after it "blew.")

 

[stkjock]

crank shaft harmonics causing oil pump gears to break.

don't bounce off the limiter and then feather the gas hard

 

[MattR]

crank shaft harmonics causing oil pump gears to break.

don't bounce off the limiter and then feather the gas hard

I see this in a lot of threads, yet guys use the WOT boxes to launch. Isn't that the same thing?

 

[ShelbyGT5HUN]

The biggest factor is THE DRIVER. Don't beat on it, all things have a finite life.

The more you use it / abuse it, you will wear / stretch parts, and they will fail. All engines have a set lifespan. Metal stretches and fatigues over time, and then one day, just go BOOM. Drive like a jack ass, all the time, especially in the heat, you better be on good terms with your machine shop.