[spectramitch]

Is comps recommendation to use the 914 springs for the Solid Roller 308R too weak? I had my e heads gone through by a guy local to me and he said I should be okay with the 914s as this cam isnt to radical. Looking for info on how to determine the right springs for my Pontiac. Thanks

308R SR Cam Specs: [email protected] 110° lobe sep. installed at 106° intake CL, Lift is .575 @1.5 Rockers, but I have 1.65 so more like .630

914 Springs: 165lbs seat pressure 365 spring rate

[PAUL K]

That is an old design cam and probably the specs they call for. Unfortunately that number was most likely based off of SBC research and doesn't take into account the heavier valvetrain parts used in a Pontiac.... FWIW I have never run a solid roller cam with less the 450 lbs of open pressure and 180 on the seat in a Pontiac engine.... But it maybe okay as is. If there is room I would shim them up. Ideally you want to be .060 away from coil bind. I'm also assuming your cam is a billet core.

[25stevem]

That’s the minimum I would run assuming that they where broken in already and have lost the 10 to 12 norm .

Also even with 365 of open pressure it’s time for 3/8” push rods.

[bluegoat65]

.575 lift x 365 spring rate= 209.875+165 seat press.= 374.875#s open pressure.
.632 lift x 365 " "= 230.68 + 165 " "= 395.680#s " " for your combo. To me it depends what the duration is @ the .200 lift. and if the lobe is asymmetrical...just my 2 pennies.