sean.b

My engine is @ 108k miles and the last 10k or so are pretty abusive miles. How many of you have pushed your luck this far, or further, and not made a puddle? I planned on tearing it down for a rebuild this winter, but I see others making it 300k miles without a rebuild. Who's crazy?

Bill Dearborn

You might want to check to see if your valve springs have weakened. They probably lose their strength faster than the rod bolts. Of course new springs will probably bring some increased rpms which might be tough on the bolts.

Bill

sean.b

I already replace those every ~14 months. Current springs have maybe 3000 miles on them. Cam isnt too aggressive @ 228/232 585/575, but it's a cheap precautionary measure. But the top end has nothing to do with the bottom end, really. And its off load RPMs that are harder on the bolts than loaded RPMs which is where the springs would help.

CHJ In Virginia

Over 20K track miles on my stock bottom end 2003 Z06, and still running strong when I sold it. Change oil regularly and springs every year. Drive it.

sean.b

holy ****. how many events or years of events is that?!

Quickshift_C5

And...how many events per year that made you decide to change springs annually?

sean.b

was told that it was a good idea with a car that lives @ high rpms with a cam that size - you dont agree?

Gordy M

2002 Z06 was a daily driver for 11 years with over 215K on it. The DD was also heavily autocrossed, time trialed and many HPDE events during that time. Also it has had a few off road skirmishes, some with tire walls. GM performance group tore it down to inspect wear and were amazed and impressed at how little there was.

Quickshift_C5

I don't disagree. I'm curious.

rfn026

123,000 +



Richard Newton
Are Your Brakes Getting Hot Enough?

SouthernSon

Bill has a point. If you track it with a high rpm camshaft and H/T downshifts you might be 'unloading' the ever living crap out of it! Of course, if you have weak valve springs lots of things can happen including loss of rpm.

sean.b

so i mean unloaded as in high rev, off throttle (no load, high rpms), at least thats what my researching said. i try to RTFM and discern who's a forum warrior and who's a builder, and that seemed to be a reliable consensus.

im from AL where the idea of actually turning your car is heresy, but everybody wants to do the 1/4 mile in 8 seconds, and the very widely accepted premise with drag engines is to not run valve springs more than a year (give or take with use) so I figure it cant be a *lot* different for road course going cars.

its also pretty accepted that rod bolts/connecting area on the piston are a weak spot with LS's pushed to competitive levels, but you guys are getting away with a LOT more than i'd have suspected based on that info!