ENGINE BREAKING UP AND MISSING BETWEEN 5000-6000 RPM

[Humdingah]

Originally Posted by finall

a) Kewl! Since very soon you will blow up your engine because you are running it up to 6K rpm. Chevy v8's are just not designed for it. Please post pics when you do!


b) Could be a computer safety cutoff feature of some sort, to keep leadfoots from doing a) above.

So you're telling me a modern Gen III or IV small block V8 cannot be revved to 6,000 rpm? What's the redline on the new Vettes...6.5 or 7K? I'd have no problem spinning one to 6,000 rpm now and then...apparently you're well-versed in modern engine design. I've got the shift points on my Lightning, with a supercharged 5.4L and just about the longest stroke on a production motor, at 5,800 rpm with no issues.

You'll run into valve float issues long before you 'blow up an angine'.

And there is no computer safety cutoff feature that does what is described...they'll have a built-in rev limiter but nothing that will cause an engine to break-up throughout the rev range to protect against spinning to a 'stratospheric' 6,000 rpm.

[MVR 155]

Originally Posted by Humdingah

So you're telling me a modern Gen III or IV small block V8 cannot be revved to 6,000 rpm? What's the redline on the new Vettes...6.5 or 7K? I'd have no problem spinning one to 6,000 rpm now and then...apparently you're well-versed in modern engine design. I've got the shift points on my Lightning, with a supercharged 5.4L and just about the longest stroke on a production motor, at 5,800 rpm with no issues.

You'll run into valve float issues long before you 'blow up an angine'.

And there is no computer safety cutoff feature that does what is described...they'll have a built-in rev limiter but nothing that will cause an engine to break-up throughout the rev range to protect against spinning to a 'stratospheric' 6,000 rpm.

No problem spinning any of the LS-X engines to up near 7K on stock parts, the limiter on my Z06 is set at 6900 rpm. Now will the truck make power over 6K.... most likely not but that is due to tuning peramaters and camshaft profile.

[H2BRUTE]

Well, after taking the car in to check out why it was missing at high rpm's they diagnosed it as the REV LIMITER, which I never heard of..Guess it's something like a governor in the old days preventing you from going too fast or in this case revving the motor too high..Guess that's a good thing. Anyhow, it is running like a champ..Guess I won't be revving it up on idle that high with the exhaust cutouts open. BRUTE ps Thanks for all your comments..I learned a ltot from this little episode..

[pdsq99f4]

Did you have a professional tuner tune your H2 or is the program just the canned program that comes with the supercharger kit? Sounds like you need some fine tuning because a stock H2 can rev to close to 6K without a problem.

[H2BRUTE]

The program that was installed is from Magnacharger. From what I gather, (per the shop that did the install) they put the rev limiter at 6K so you never over rev the motor. That is the way they make sure your Hummer lasts for 100K miles or more. BRUTE