how to raise compression ratio

[92ranger18]

I want to raise to comp. ratio of a 302HO without having to buy a stroker kit, just bore and stroke forged internals. what type pistons would work with P&P stock heads that wont have clearance issues with the valve? I want to run methanol in this motor. any advice is appreciated

 

[projectnitemare]

compression has nothing to do with a stroker kit. Go to either a flat or dome piston, smaller chamber heads or shave the deck. All will require clearances to be checked. If you don't know where to go about doing this have a shop build it for you.

 

[adsm08]

Well it kinda sounds like you don't understand compression ratio or "bore and stroke" from that post, so in the interest of education I'll go over it from the beginning.

The compression ratio is the volume of the combustion chamber vs the total volume of the cylinder. So if your chamber is 1 CC and your cylinder volume at BDC is 10 CC your compression is 10:1.

To raise compression you have to lengthen the stroke of the piston or make the chamber smaller. Boring things out won't get you any compression worth having.

Stroker kits don't really raise compression as much as you think. Piston configuration has the most effect since a normal 5.0 has a dished piston which adds to the combustion chamber. A flat top piston will be best.