So far no one has experienced a stock lifter failure due to high rpm's. I was informed about one today. The heads had the extra heavy valve springs designed to take the motor above 8000 rpm's. One hundred miles on the motor and a single lifter failed @ 8000 rpm's.

 

What kind of damage did it cause?

 

It appears to be just the lifter. The motor gives off a ticking sound. Probably the cost of one lifter and about eight hours of labor. It could have been alot worse.

 

ouch... i'm not sure why the fascination/insistance on going to 8K etc...7K-ish is fine for me... I guess it depends on the size of the turbos you're using as you end up shifting your power band around. The larger the turbos, the more lag and so your power band moves from 4.5K onwards...

 

sharkster,

I have never understood taking lifters that come factory rated at 6800 rpm's to 8000 or anywhere close. You take the stock rods to 7500/7600 rpm's enough times and you will bend them. It seems that Porsche has about a 8-10% safety factor in their parts and after that you are shortening the life and asking for trouble. Then again, this is only one ........... maybe it is a fluke?

 

Roger that. Seems like pushing the envelope waayyyy too far into the danger zone. I'm sure there are others we've not heard of as yet

 

This was in your car Chad?

 

No it was not my car or one of my motors.

 

this is what a collapsed lifter sounds like.

http://videos.streetfire.net/video/6...43cb4551e8.htm

 

That sounds like a porsche motor

 

My motto is **** happens at high rpm lol. If I ever make a pass in my Camaro again I have the rev limiter set on at 8000 so I can make it through the traps lol.

Luckly you fixed it before things REALLY got bad!

 

Chances are your Camero isn't running bone stock lifters with a high performance cam/springs. Or is it?

 

No it has everything aftermarket (Lunati Lifters, Comp Springs, Cam-motion cam, Jessel J2K Rockers (It's solid roller)) but even then just like the Porsche they aren't made to be rev'ed that high still. Only motors I've ever seen rev really high are most of the import's like Honda's that rev to 9k and 10k RPM!

What kind of cams (GT3?) were they using to run up to 8000 like that. I shift at 6800 or so and I think thats high enough, but then again I have baby little K16s

 

Correction: You can use GT3 Cup heads and cam housings with what they call the "half moon " lifters. Stock 8600 rpm's and good for about 10% more. Or you can make your own to match the material of your cams like we did.

 

Ahh nice. These motors, PCMs, etc. are all still new to me. It's totally different then lets say the LSx based motors, but they have had a little bit more time for R&D. I'm interested to see what the rest of this year holds as far as these cars go. I'm sure you all (you, promotive, Imagine, etc.) will find even more ways to make insane HP this years.