Quote:
Originally Posted by Cliff R
The cast piston options for the 400's are absolutely pure bovine excrement and always have been. I still remember mocking up an engine I was hired to assemble decades ago using those pistons. They were WAY down in the holes at TDC and already taking over 15cc out of the squish area like using a dished piston. Team that up with a 4X or 6X-8 head in a 400 build and you'll have about as much compression as a Briggs and Stratton lawn mower engine, and left wondering why it doesn't idle or run for chit once placed in service......
|
I had them in a build that was done in '82. I asked the machinist to do a zero deck. I found out he did not and was glad for that as the pistons were .040 down. Swapped heads to a 6X-4 to alleviate detonation. Resulted in a CR of 7.6. Engine still ran ok . Swapped pistons to the heavy SpeedPro which brought the CR up to 8.2. Still not great but the engine runs much better.