401 .20 Pistons

[JMSII]

I have been looking high and low for cast, stock 401 pistons in .20 - anybody know where I can find them? Thanks!

[jeepsr4ever]

:idea: Unless someone has a set of badgers from back in the day your stuck at .030

[JMSII]

MC,
Depending on who you talk to, some people think that going .30 over will cause heating problems. What has been your experience with .30 over 401's? Any problems with running hot?

All of my 401's are still standard, but the one I am rebuilding is just a hair past standard and I don't want to lose any more wall thickness than I have to.

Thanks!

[MikeJames]

Everywhere I've read, it's .60 over that causes problems, I haven't read anything about .30 over.

Mike

[jeepsr4ever]

I have seen and done .085 over without any heating issues. Not all blocks are born equal :mrgreen:

[JMSII]

Ok then, who's got the "deal" on .30 401 (cast is fine) pistons that will yield about 9.5 to 1 compression ratio with 58cc heads? Anybody?

[fifesjeep]

I know advance has cast pistons for the 304, 360 etc.. I'm not sure about the 401... It wouldn't hurt to call. Have you checked ebay?

[JMSII]

I check ebay about 6 times daily. The only thing they have are the .30 over cast "high compression" pistons from maddog. When I inquired they said it would yield about 10.5 to 1 with the 58cc head - bummer! I don't want to go higher than 9.5.

Perhaps I could try and scrounge up a pair of 291 heads - anybody have any?

[82Waggy]

KB 354 have a 28cc step dish that will yield about 9.7:1 with 58cc heads.

BUT: They have smaller wrist pins that require the rods to be bushed - which is not necessarily a bad thing but adds cost.

Shoot for zero deck clearance with an .045 thick head gasket for a good quench.

Unshroud the valves and you should be at around 60cc and 9.5:1cr. Open the chambers to 65cc and you should get closer to 9:1.