I am building a mild 327 for my ElCamino. Got a set of 461 heads in a trade, with 2.02/1.60 valves, and dual valve springs. My cam is an old SSI cam from PAW, identical to the 350 horse 327, but with slightly less(.436 )lift I have seen plenty of stories about removing the inner springs for break in, but always on the larger cams, and a few guys saying the older style cams would be ok. The other question is, can i remove the inner springs and run the outer only(for the life of the engine, not just break in) or replace with a stock diameter , appropriate spring? (the seat has been cut)my ultimate goal will be to add 1.6 rockers to bring the lift to .466. Thoughts? I've researched this somewhat already, but all old info.
Is the cam coated with break-in lube? 0.436" is not a ton of lift, neither is 0.466". I would put/leave the dual springs in, lube up the cam and lifters, run a Zinc-rich oil, do a proper break in, and not worry. Old info is still good info. The metal does not know how old it is.
Always run the double springs,this would have been catastrophic with my 327 had I done what you propose. After this happened I replaced them all just to be safe. HRP
Find out what he springs actually have for lbs. and then talk to the cam grinder. Nothing wrong with break in with one spring but you need to know the cam and springs are matched.
Not a matter of dual or single but the spring pressure. If high on dual some are removing inner springs until break in is done. As Joe said, you need springs that match your cam.
as others have said, knowing your spring pressure is important otherwise your jut guessing and taking a risk of cam damage and valve train problems.
327s like to rev so a stable valve train is important. Know what your installed height is and check the spring pressure at the installed height. The flat damper is to keep the harmonics under control. Modern cams have much better springs and seldom require double springs for street use.
The message here is to make sure "Installed Height" is all the same..you will need various thickness spring shims to correct this..as all valves may not be sunk in the head the same from seat grinding operation..Therefore there will be different amount of shims on each spring seat.
With that cam you don't need dual springs, I would run stock-ish springs with dampers. You know like the old power pack heads. If you run too stiff a spring on that cam you'll flatten it.
The heads were a trade, so the specs are unknown. I talked to my machinist, and am just going to take the heads in and have him look at them and make his recommendations. Sucks because its all together, but I should have thought of this first. Been about 10 years since I've built a small block. Thanks for the advice guys.