Seasons Greetings All, i am tweeking my b20,sort of a mini mppe and was wondering about valve to piston clearance. What would be a minimum figure i could get away with, what would be safe and to Phil S and the likes, what are your measurements and any downsides i should be aware of. Cheers David

do you mean piston to cyl head? the piston can be 10 thou above block deck and not hit the head.

Look at the combustion chamber shape of a B20. The valves are perfectly vertical. The valve has to to open a whole lot before it interferes with the piston. Non-issue, unless something breaks.

It's a vertical valve engine, so valve to piston clearance is not something you need to worry about.

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Three 164's, Two 144's, One 142 & a partridge in a pear tree.