Valve springs

winstar

vocky said:

alanoo said:

I don't consider the GM sc powerful enough to bother with :o

I sort of agree a SC is alway's only going to be good for a certain amount of extra power due to how a roots blower operates. The Harrop improves things but it's still not that good above 1.7 Pressure Ratio (about 23 PSI boost), now a SC + turbo system would be a different matter.

However I will add currently owning a VXT with 305 lbft of torque has taught me that in a VX headline power figures aren't everything. In a stright line it's as fast as the new gallardo but it's nowhere near as easy or fun to drive as my NA is round the bends, although that could just be the power delivery.

alanoo

94 are a lot too stiff for NA use vocky.

Normally, you go stiffer when you hit large amounts of boost (as the air pushes the valves with boost) and high temperature (which changes the springs properties), but these are not needed for NA use.

Schrick ones are ₆₉ lbs
The NA Roush built of the 3rd build book uses PSI CT1530 springs, these are 80lbs
Having springs that stiff on an high RPM NA application would lead to premature valve, valve seats wear and possibly followers failures

Oh, and it eats some hp too 😉

vocky

I choose 94's as thats what the gm racing are, I thought the higher the spring strength the higher the revving

nickb777

I picked mine up yesterday, thanks to Davemate(.org) they look really goodI need to fit them now. :thumbup:

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