xtturbo

im looking too freshin up and old motor i have lying around...gonna throw in a .499-.499 lift cam. will i need new springs or will my stock springs handle it? and another thing..the motors out of a 1990 lx 5.0...will my valves clear the pistons?

Joel5.0

Get new springs/retainers...OEM springs are only good for OEM cam (at the most)...options?...plenty out there, TFS, Crane heads upgrade kits, FRPP, Lunati.....regarding the valves clearing the pistons....total valve lift is not an issue, PtV clearance is an overlap period concern (exhaust closing, intake opening at the same time). What are the specs on the cam?..

ikeybmg

well ive heard they were rated for .525 lift. people install the E can all the time without changing them. its .498 lift so .499 should be O.K. i guess if you want to be safe you could upgrade. if its high mileage i would upgrade. if not theyll be fine.

AdderMk2

like ikey said... they will be fine, but if its got miles on it... why would you wanna use old weak springs?

Joel5.0

They "work", but performance is hurt and the "risk" of valve float and coil binding is there....look at the OEM valve springs specifications:

Intake:
Valve Closed Installed Height: 1.8"@82#
Valve Open Installed Height: 1.33"@230#
Coil Bind Height: 1.250"
Lift to Coil Bind: .530"

Exhaust:
Valve Closed Installed Height: 1.6"@85#
Valve Open Installed Height: 1.15"@226#
Coil Bind Height: 1.090"
Lift to Coil Bind: .510" = reason why it's said they work until .500" anything over .510" it's not a spring anymore, it's a solid chunk of metal that could cause valve train problems.

A good set of springs, in addition to the correct spring rate, needs to be at .060" above coil bind height or .470" intake lift and .450" exhaust lift for the OEM springs....reason why the springs are only "good" for the OEM cam (.444" lift). My 2¢.