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Author Topic:   Z28 springs ?
posted September 14, 2004 07:44 PM
are the Z28 valve springs good enough for 7000rpm? lift is 535 . and do stiffer springs cost you hp. or not?

posted September 14, 2004 07:53 PM
yes they'll be fine but as a good practice get the 600 lift springs and change them every year

posted September 14, 2004 08:23 PM
if u can put comp cam's springs in they are stiffer and won't float the valves WON'T break and let u turn more RPM's than z28 i only had 8 nights on my z28's and two broke in one night

posted September 14, 2004 10:31 PM
but you broke your z-28's with too much actual lift
you were upa round 600 lift and thats over max for the 600 lift springs

posted September 14, 2004 10:35 PM
Is it necessary to run the inner damper springs on the stock diameter .600" lift springs, using a .536" lift cam?

posted September 15, 2004 06:45 AM
that dampener is there to quell the bad harmonics. i wouldn't remove it...

posted September 15, 2004 07:52 AM
to be honest i wouldnt run the true 'z28' springs over about .480 lift. There are some aftermarket springs generically called z28 springs that might be good for a little more but for a little more money i would at least get the comp springs. The little bit stiffer springs wont cost you much if any HP and you get a more stable vavletrain.

posted September 15, 2004 08:58 AM
I've said it before and I'll say it again......these "Z-28" springs are not a good idea for some motors. .535" lift and 7000 RPM is definately one that I would NEVER use these springs on. Remember, when talking about the right springs, it's all about pressure and these springs don't have much. I did a lot of research on these springs last year and didn't like the results.


posted September 15, 2004 11:43 AM
hey xteme i found out what really was wrong did u see our rocker arms???? we have the comp cam forged rocker arms and they have long rails on them to keep them over the valve and our feeler gauge was to wide and it was measuring it on the little rail so they were WAY off so we got that fixed lol

posted September 17, 2004 08:24 PM
run elgin rocker arms... you are still running a lot of lift... i've not once had a problem with my 600 lift z28's at roughly 550 lift each side turning 7000 all year...