Valve spring pressure sanity check

[40cpe]

8BA with new valve seats, Manley Pro Flo valves with Chevy stems with one keeper groove. Cam will be a regrind, either L100 or 1007B. Street engine of 276". I'm checking spring pressure to see what more parts to order. I can only find rotator style keepers. I have non-rotator keepers somewhere that I haven't found yet. I have 1.934" installed height and 45# at installed height using rotator (short) springs and 75# using the longer spring. Opinions, please, on using the 75# pressure with the rotating keepers, or should I buy or find my non-rotator keepers and use the longer springs and shims and shoot for 50-55#?

[flatjack9]

I'd shoot for the 50 - 55 lb.

[Ol' Ron]

Ditto

[40cpe]

If I shim the short spring at 45# am I likely to have coil bind on a .350 lift?
What thickness shim do you think it will take to turn the 45# into 50 #?

Thanks for sharing your knowledge with us.

[KiWinUS]

50-60lb MAX !!!
Gene it is really not possible to guess accurately on what shim it would take ! Anyone can guess , but guessing is not how you build a great engine ! Coil bind is real bad also , as is valve hitting head !
Good Luck !!
Cheers
Tony

[40cpe]

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Thanks Tony. My thought was that someone who had used a .060 or .030 might remember how much it increased their pressure. That is certainly better than MY guess.

[KiWinUS]

Gene a .060 shim can substantially be different from spring to spring . Sorry to dissapoint but thats the way it can be. Just always like to be cautious !

[Walt Dupont--Me.]

Originally Posted by 40cpe

8BA with new valve seats, Manley Pro Flo valves with Chevy stems with one keeper groove. Cam will be a regrind, either L100 or 1007B. Street engine of 276". I'm checking spring pressure to see what more parts to order. I can only find rotator style keepers. I have non-rotator keepers somewhere that I haven't found yet. I have 1.934" installed height and 45# at installed height using rotator (short) springs and 75# using the longer spring. Opinions, please, on using the 75# pressure with the rotating keepers, or should I buy or find my non-rotator keepers and use the longer springs and shims and shoot for 50-55#?

Ditch the rotor stuff, about any of the dealers have the non rotor keepers JOB LOT for one. Don't use the short rotor springs, the stock long springs with one .060 spacer should be close to 50# may have to add a .030 spacer. Walt

[scooder]

Why not measure it? You got X pounds at installed hight, now put more pressure on the spring till you get your desired poundige and measure the hight, the difference between this measurement and your initial installed hight will give you the shim thickness.
Martin.

[Ol' Ron]

I doubt you can use a short spring o an L-100 without causing coil bind, never tried.

[40cpe]

Thanks guys, long spring it is.