[401bluebird]

I remember a few years ago talk about forged pistons for 401 V6s. somebody mentioned that the size of the larger 478 piston was greater than forged piston blanks which the piston builders machine into the required configuration.

Even though large pistons are being made now for aftermarket blocks which increase the bore centers to 5.3 inches (the Big 3 big blocks are all under 5 inch B.C.). Maybe these new forgings can accommodate a 5.125 bore (or +0.30 at 5.155).

I know that the Reno Air Races have dozens of rolls Merlin V-12 engines. I see that a standard bore R-M V-12 is 5.4 inch diameter. Maybe these forging blanks can be used for a slightly smaller piston diameter.

Custom pistons are never cheap but to build a higher compression 478 will require custom pistons.

Anyone know of any piston manufacturer who sells a 478 +0.030 high compression piston?
thanks,
-Andy Carlson
Ojai Ca