the cylinder head

Doing The Head by Double H (January 05, 2008)

A Twin Cam Cylinder Head

hen it comes to squeezing another few horses out of a naturally aspiratedmotor, the key area to focus your attention on is the cylinder head. This is the one area that will potentially give you the greatest increase in engine power. Why? Well, as Langer mentioned in engine building and power basics, the key to increasing horse power is air-flow. And on a motor car engine, there are three areas that affect air-flow:

• The intake system, which includes the air filter, plenum and the intake runners.
• The exhaust system, which includes the exhaust header, catalyst converter and the mufflers.
• The cylinder head, which includes the cylinder head ports, valve area and the camshafts.

e discussed the intake system and the exhaust system elsewhere so now it's time for discussing the cylinder head. But in this section we're going to discuss a bit more than just the cylinder head, we're going to discuss cylinder head porting, gas flowing andpower tuning the cylinder head, old school style. We'll also be discussing performance camshafts, cam timing, valve timing and valve overlap. A word of warning though, cylinder head porting and gas flowing is not for the faint of heart. It is a skill that must be developed and honed by practice but it almost always begins by trial and error so if you're going to do your own cylinder head porting, start on a cylinder head that you can afford to destroy. Otherwise you should leave cylinder head porting up to a professional with a flow bench.