I have bought a new cam and valve springs matched by Comp Cam. The installed height is supposed to be 1.80". I am all over the board on my spring heights but am afraid on a couple of valves that I may not be able to shim up high enough without covering up the spring locator (bad idea). Has anyone ever used a variable height valve stem lock? Reading that they can give you + or - .050 installed height which would make the rest my project a snap. I would only need this help on 4 springs where my current installed height is 1.885, 1.880, 1.895 and 1.885.

 

is it a hydraulic, roller or solid cam? what arm ration are you using?

 

I'm using stock rockers 1.73:1. Cam is hydraulic lift ex .493 and in .506. I bought a set of the locks and was able to get installed height.

 

IIRC the installed height on an fe with 1.73 ration is 1.82. I also would be more concerned running the spring below he specs because you could collapse it. But still, having springs with diff heights is little out of spec. Your lift is not big enough to cause a major concern but check your seats - they might be collapsing. Btw, are you using new valves?

 

No, the valves had been replaced when I got them 3.5yrs ago and had hardened seats and some intakes replaced as well. I also have a set of 1968 heads and they are off almost exactly the same way, I just figured that was the way it was with stock heads. I was running a cam of almost same lift of intake with stock springs set up at 1.82. I felt it would float at higher rpm's the springs I got with that cam were too stiff to use so just put up with it. Wanted to make sure I did this right. Supposedly, Crane doesn't recommend these locks with stock retainers but they fit better than the others I was using. They are 7 degree and will accept 3/8" valve stems.....I only used them on springs that were to tall to shim imho.

 

Whenever something is being replaced - replace with guidelines from a manufacturer. Using springs from Crane should be followed with retainers and locks from crane etc. Somethings dont fit well with others.
​​​​I would change those old valves. You dont know who where or what they are. $70 gets you stock 390 valves. Depending on your build.

Cheers.

 

Am I wrong in thinking that if you lap a valve in the seat it is going to extend that valve tip on the spring side? We are talking thousandth's in the measurement department. I just don't see how anyone can expect to have same spring height (w/o shims etc), on heads that are nearly 50 years old???

 

Whats the open/seat pressure with the springs you have?

 

I decided to not take chances and ordered comp retainers and locks. They only have -.050 locks on 10 degree so that is what I had to order but at least the retainers are stock height.

 

GOOD MAN!

Leave the mix and match for the NASCAR boys.

It depends on how far you are taking the modification(s).

The valve stems can be trimmed to match (final installed height). Of course this will require more absolute shimming to arrive @ the correct spring height/pressure and must measure for any possible coil bind.

Or you can install all new seats. It depends on how fast you want to go and how much money you have.

 

Did you get the 226/241 thumpr cam, if so did you use stock pushrods and what valve springs did you get