Re: valve springs
Quote:
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Originally Posted by johnwb
Need some help please,I have an M-6250-E303,cam that I am trying to use in a 1990 5.0 liter,I used crane dual valve springs part #99838-16 and crane retainers,the heads are e7tes ( factory)
The problem I am having is with installed height .wich should be about 1.650 and I have about 1.825,I cant make that up with shims,should i get another set of springs,or has anyone tried running with this the way it is?
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John;
Your problem is a springs/retainers mismatch. Even with the right retainers you would still have to shim that spring to get them to their installed height spec of 1.650", anything above that and you're losing seat pressure on the valves @closed position (based on the specs @Crane). The closed valve pressure will fall below the 110# recommended for HR cams.
SBF valve springs installed height specs are in the 1.820" - 1.780" (1.160" for the exhaust valves) depending on the retainers you use. One of the better choices would be #99846-16 w/0.020 shims, these have ± the same AVG spring rate as the ones you have and should provide good pressure for the E-cam w/out any coil binding issues. Another alternative would be the M-6513-A50.
Forgot to mention, these springs are single w/damper if you still want to go with real dual's, the M-6513-A351 would do @1.820 IH.
My 2¢. LUK which way you go.
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