Redifined 964-Case - The rigors of competition have served to pinpoint a number of problem areas with the factory 964 cases. First and foremost was to eliminate pesky oil leaks attributed to gasket failure. To cure this, the PENTA 964 cases are machined for O-ring seals between the case halves, chain covers, cylinder spigots (107 or 109mm) and the breather housing. Spacing between the main bearing bolts has been increased from 118mm to 120mm to avoid breaking into the cylinder barrell bore. The cases are made of 356 aluminum alloy and thoroughly preccision CNC-machined. Removeable O-ring plugs are employed to provide easy access to all oil galleys for cleaning the case. Special removeable oil "squirters" are included to help clean and cool the piston/rod assembly.  (Oil squirters come standard @45psi release pressure with other options available at customers request).