This is a very common issue and easily resolved, Machining the domes for adequate,spark plug,clearance,

The heads may be capable of flowing (x) on a stock engine but with careful selection of a cam with the correct duration and lift, and with a tuned header, and matching valve train mods along with some port and bowl clean-up the resulting improvements can be significantly more impressive.Īny decent, experienced machine shop can measure your cylinder heads combustion chamber,Īnd calculate the required clearances after measuring your heads combustion chamber, and then do the correct machine work on your piston domes, The most common mistake made by many people is that they fail to look at an engine as an interconnected group of component sub systems and they don,t realize that changes to a single component, no mater how much potential that component has is not going to allow that component or change in the potential to be realized until all the matched and supporting systems have similar potential. The following equation mathematically defines the available flow area for any given valve diameter and lift value:Īrea = valve diameter x 0.98 x 3.14 x valve liftįor a typical 2.02-inch intake valve at. Ideally you,ll want to un-shroud the valves while opening up the combustion chamber volume, but not extend the combustion chamber past the front edge of the gasket fire ring as that usually causes gasket failure (notice the gasket fire ring is NOT a perfect circle like many people assume) You,ll want to place a head gasket you,ll use on the heads and mark the area inside the opening as the only areas you can change, Head gaskets are rarely completely round, nore are combustion chambers Some excellent info well worth reading thru

4 valve combustion chamber