Making power out of the 318

carmart1975 said

I really like your thinking i think i will use what i have and use some kind of KB piston but i am a little lost on that should i use 399s or 167s if you dont know thats ok i will dig deeper into the internet

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Look for flat top pistons that will put the piston top level with the deck surface. That enables good flame travel across the piston and will work with almost all heads. Piston to valve clearance is the catch phase on that. Big valves won't clear all piston valve reliefs. The valve reliefs can be enlarged later if required, but best to account for that up front.
Same goes for relief depth, with a milder cam you would have lots of clearance at the expense of a bit of compression. DV also speaks about piston porting. This involves dressing the sharp corners at the edge of the relief and also cutting it back to allow the incoming air to easily flow into the cylinder while the head is still close to TDC. Attention to details add up. The piston porting is dealt with in his BBC book.