valve springs
 

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?

Re: valve springs
 

OK, first of all you're .175" off the mark. But you're thinking BACKWARDS. "Shims" are gonna make your problem worse by raising the spring height, basically raising the bottom of the spring by whatever shim you throw under it.

If installed height is supposed to be 1.650 and you're at 1.825, you're already to tall. You need to take shims OUT. Look around REALLY carefully, sometimes those suckers are hard to see. They stick to the head, the spring, etc etc. Get yourself an icepick, start feeling around the spring perch, and you might be surprised at what you find. ;)

Re: valve springs
 

Thanks for the reply,i am pretty sure my problem is that the spring height is too high unless I measured it incorrectly.I measured from the top of the first coil to the spring seat and i get about 1.825 installed.If i need 1.650 doest that mean i need to actually compress the spring more?

Re: valve springs
 

Your installed spring height should be the measurement of your SHORTEST installed height that you got from all your springs.
Is 1.825 your shortest measurement you recorded?
Since you have double springs, are you allowing for the inner step on the retainer.(measuring to the inner step on the retainer)

Re: valve springs
 

Thanks for the reply,1.825,is actually one of my larger measurments, the closest i have to the installed height would be 1.798,you asked if I allowed for the inside step,are you talking about the inside spring. I have only measured the height of the outside spring,mabey I am going about this wrong?

Re: valve springs
 

I was talking about the second "step" on the retainer, that you should measure to.
That should be for the inner spring. It's ok for the springs to be within .020" of each other(installed).

Re: valve springs
 

Check out this link. It might help you: http://www.cranecams.com/?show=faq&id=5

Re: valve springs
 

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.

Re: valve springs
 

Thanks alot for the info,funny summit suggested the springs and retainers I have for this now ,I think Ill take another look and try another spring and retainer combo.