Return to Website

Explicit Speed Performance

Explicit Speed Performance
Start a New Topic 
H22A Head

I'm building an all engine H22a everyday driver. I have the bottom half done, Darton sleeves, Eagle Rods, 11.5 to 1 JE Pistons, and Race ACL Bearings. No Crank work. I would like to have a ZEX nitrous sytem at some point installed. With all that said, what do I need to do to the head for the most performance, and reliability. I know there are different size valves as well, what are the pros and cons to bigger valves? Any help would be greatly appreciated.

Re: H22A Head

Larger valves are usually wanted in boost applications such as what you want to do. There is a gain of hp going to a larger valve as big as 1mm I believe is the biggest you can go most common is .5mm. Just the matter of how much of hp gain is unknown. I usually stick to STD size for NA builds and .5mm for boost builds. As far as the head definetly you will want SS valves. So they can take the abuse and heat better. The right valve spring with the right cam is crucial. Too hard of a spring may wear out the heads internals. 11.5-1 compression is too high I think for boost. Your better off going NA with that. The best NA cams on the market right now seem to be the skunk2 pro 1's and pro 2's. The pro 1's are close to the old skunk2 stage 2 specs. The pro'2 I think will satasfy your need for speen get the matching Valve springs and if you have the dough valves. If you don't have the dough a cheaper valve company such as super tech will be fine...