TPR017 - Drop In Pistons - Pro R

Forged Polaris Pro R drop in pistons  Designed by TPR & manufactured by CP/Arias    IMPORTANT READ: These Pro R pistons are a direct replacement giving you options for compression ratios, larger cams and oversize valves. Pro R engines are extremely tight on piston to valve clearance limiting you on upgrading your cams and cylinder head. We’ve found the BC .430 lift cams are all you can upgrade to with a stock piston and they are very close with not much room for a hiccup. Installing a race prepped head with larger valves and cams is not possible without an aftermarket piston with valve reliefs. TPR pistons are designed to work with our race prepped cylinder head and any other head with up to a +1mm intake and +3.8mm exhaust valve and up to .465” of lift. Gas ported ring lands and gas nitrated steel rings are all standard features.  Turbo pistons are good for up to 1000hp.   Something to think about: If you are using a ported head with a CNC profiled combustion chamber this will usu