Thread: Rookie cr/head/piston questions 402 bbc

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ok i am building a 402bbc that i am trying to get 500 hp out of. Im a little confused on open port closed port heads and pistons. Im looking for about 10.5 to 1 compression. I have a set of 820 113cc open ports, and a set of 236 113cc open ports. I am looking for a set of forged pistons. But most are for closed chamber heads, probably because 396s were closed port, and 402s were open port, ive heard you can use open port heads on closed port pistons, it just drops your cr a point or so.

keith black sells kb9949 -41cc domed, 11.5 cr with a 112cc head, what compression ratio would i be running with a 113cc open port head??

also summit racing sells a sealed power engine rebuild kit, pistons/rings/bearings/gaskets for a 396, with 11.88 cr with a 106.9cc head, i dont know what cr that would get me either.

This 402 has a steel crank, im also wondering what rods to use, ive heard 366 bbc truck rods are better that stock.

also im wondering which heads are better to use, i do plane on putting bigger valves in them, and also some mild porting.

any info would be appreciated

thanks ken

I used these pistons in my 402 build... Speed Pro ZL2328F-30 Forged Pistons....0.319 Dome ...With the 820 heads 110cc...Which if I'm right it should be around 11.0 compression.

But...Pat will be able to help you......He's the Big Block Wizard !!!!!

Originally Posted by hotrodd64

ok i am building a 402bbc that i am trying to get 500 hp out of. Im a little confused on open port closed port heads and pistons. Im looking for about 10.5 to 1 compression. I have a set of 820 113cc open ports, and a set of 236 113cc open ports. I am looking for a set of forged pistons. But most are for closed chamber heads, probably because 396s were closed port, and 402s were open port, ive heard you can use open port heads on closed port pistons, it just drops your cr a point or so.

keith black sells kb9949 -41cc domed, 11.5 cr with a 112cc head, what compression ratio would i be running with a 113cc open port head??

also summit racing sells a sealed power engine rebuild kit, pistons/rings/bearings/gaskets for a 396, with 11.88 cr with a 106.9cc head, i dont know what cr that would get me either.

This 402 has a steel crank, im also wondering what rods to use, ive heard 366 bbc truck rods are better that stock.

also im wondering which heads are better to use, i do plane on putting bigger valves in them, and also some mild porting.

any info would be appreciated

thanks ken