Valve Spring Pressure

[Changin Gears]

Shims aren't a bad idea, 15 lbs would put me well into the safe zone. I've only used them once and as I recall you want hardened ones. any  recomendations on what ones to use or does it matter?

You want the ones that the hole size match part of the head that supports the guide so they won't walk.  .060" shims a plenty strong, its those .015" the self destruct.

[AMXguy]

90 + 15 would be 105 lbs, Comp says 110 for a similar cam so that's close enough for me.  for the way I drive my cars I'm probably fine as is but I can do this easy enough on the engine stand I might as well just do it.

[72cudamaan]

just make sure you check your installed height.  You dont want coil bind.

[Strawdawg]

Be sure you check to see if the pressure is actually what you calculate it to be.  The comp cam I listed is almost identical to yours and the springs that go with it are 122 psi valves closed.

When you bend one of those big valves, the cost of that repair, along with the other stuff that has to be replaced, may make a set of the correct springs look cheap...on the other hand, if you never rev it up, you might make it

[AMXguy]

After an hour on hold I talked to the comp tech line, with my specs he told me to use the 924-16 springs which have a 112 lb seat pressure.  I'm just going to do it and be done with it, not enough spring to trash a cam so I'll go that route.

[moper]

The question is not what the springs should be, but are in your heads. If the heads are re-done, the installed heights will more than likely be different from the factory setup. So to know if your springs are "good enough" or not, you ned to do a couple things: first, pull a couple springs off the heads and secind, put the retainer and locks back on it and measure teh distance between the spring seat and the bottom of the retainer. That is the actual installed height of the springs on your heads. Then take that measurement and using a spring testor, check the tension on the ones you removed. The reason to do this is simple.. Just like the shim ading rpessure from on the seat to max lift, a cut spring seat, or new valve seat cut a hair deeper and the tension is reduced at all points. And running too light will work but only for a while. Springs wear and using one that is maxed out and still light will lead to it failing much faster than one that is spec'd and setup properly. Too much is always better than too little in valve springs.