Quote:
Originally Posted by gobrdgo
I also was hoping to re use the valves, that being said shooting for a 1.6 installed height is getting difficult with 125-130 lbs closed valve spring 320-350lbs open. So I could always cut the valve seat .100 to make up for that problem? If I have to replace valves for longer ones do they make non dished valves as my rough estimate with a .030 over 455 and 96 heads makes like 9.37 comp with a .030 head gasket. Hate to lose any more compression with the dished valves.
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There are not issues cutting the spring seats .1” deeper if you need to. If you used a small shim, the Crower 68404 springs should work for the spring pressure suggested with stock length valves.
The new replacement valves like ferrea and Manley do not have much dish and really loose very little cc’s against stock. I would replace the stock 2 piece OEM valves if that is what is in the head yet. Especially the intakes. It is never worth the time to regrind a set of 2 piece valves that have a bunch of miles on them, they can break the valve head off and destroy the engine. Replace them with a one piece.
If this is an econo build street engine I would not get wrapped up and a bunch of little mods like a .030” thick head gasket and the small 7* dish in aftermarket valves. A .030” gaskets would probably be a cometic, they require a glass like surface to seal up correctly. If your trying to save money that means more machine work. Jmho… If your ported heads, you will find more power in the heads than a couple tenths of compression.
Generally low lift flows are found working on the ceiling with the bowl smaller, and higher lift flows come more from working on the short side radius with the bowl opened up more. You could likely get the low flows back close to what they were with some work on the ceiling. Common for 45* valves loose flow against the 30* up to .3” lift. Maybe I read wrong, but looked like the 4x have 45*?