396-375 Piston Question

[Mike Fuller]

I have been told by a number of people that the CP piston numbered C3-CP will hit the combustion chamber of the 401 aluminum head when all the correct measurments and volumes are used. I am using JE (JE 193518 )piston in my motors and do not have this issue with these pistons.

I am aware that there is a new CP piston listed in the NHRA accepted product list (C3A-CP) as well as number of piston that were added recently.
Diamond and JE have added new pistons to this list. Has anyone had the opportunity to put together an engine using the new CP's or any other piston
for that matter, to determine as to whether or not it solves this problem and still performs well?

[Jim Hanig]

Originally Posted by Mike Fuller

I have been told by a number of people that the CP piston numbered C3-CP will hit the combustion chamber of the 401 aluminum head when all the correct measurments and volumes are used. I am using JE (JE 193518 )piston in my motors and do not have this issue with these pistons.

I am aware that there is a new CP piston listed in the NHRA accepted product list (C3A-CP) as well as number of piston that were added recently.
Diamond and JE have added new pistons to this list. Has anyone had the opportunity to put together an engine using the new CP's or any other piston
for that matter, to determine as to whether or not it solves this problem and still performs well?

Mike I have built several with the cps and yes they hit. Ask Bruce at Houston one year when they tore one of the Emmons engine and they had hit , can i do anything to stop this ,his answer you want to modify the p[ston ,no. Jim Hanig

[dahkahuna]

CP pistons has a history of selling big block pistons that have a interference design flaw this was the cause of the destruction of my Aluminum block ZL-1 in 2008 at Pomona. Although the engine rolled over and seemed to be ok, at RPM the pistons would hit which caused my catistrophic failure at Pomona. I can only believe that as the engine builder I should of clayed the areas to check how close the pistons were, Pennington at CP assured me that the problems had been corrected and that everything was ok, because Darrel Wikle had told me he was having problems previously with fitting the 401 heads I took Penningtons word they were ok,THEY WEREN'T. So buyer beware, always confirm your clearences,buy the way the 2nd set of pistons from CP had a redesign of the dome area where the problem was.

[Mike Fuller]

I have noticed that CP now has a new piston listed (C3A-CP). I will have to call them and see if this is a fix for the problem.

[Alan Roehrich]

Originally Posted by Mike Fuller

I have noticed that CP now has a new piston listed (C3A-CP). I will have to call them and see if this is a fix for the problem.

Mike, you have a PM, I'm sending it now.