502 block ????

[racer_99]

I have a 502 block that is already at a 4.54 what would you guys consider the block could be safely bored to and run boost on it? Also what do you think the max HP the bottom end of a 502 will take? Also what is the largest stroke you can put in the 502 block? any and all info and advice will be appreciated.

[doorslammer71]

I know Reher-Morrison used the 502 block extensively quite few years ago. Before you could get Dart Big M's easily. They were bored to 4.560 for the 555 deal, at the time with Dart 360's they were making in the upper 800's for HP. Now they are running Dart block with CNC 345 pro1's at 950hp plus. We put quite a few together for mild race motors as 510's and 540's even one on blown alcohol. I say the casting quality is generally better than the older 454 blocks, going to 4.56 should leave enough cylinder wall thickness BUT it should probabably be filled with hardblok up to the waterpump holes if your going to beat on it, to strengthen the walls and help hold the bottom end together. Roots blown iron BBC's tend to break the #2 main web eventually. Honestly, if you want to make more than 800hp, I would sell the block to someone who wants to build a big inch street thumper and then buy a Big M or Bowtie sportsman block, either will run you around a bit more than two grand. PM me if you have questions, I'll tell you what my experiences have been. JJ&BTP

[doorslammer71]

sorry, didn't see your stroke question right away. 4.25 is the easiest, with a 1/4 long rod pistons are available from muliple sources for compression ratios. You can even go .400 long but the ring pack is kind of tight for boost. I put a 4.375 in a short deck but the custom pistons, fitment, rod ratio, etc. wasn't really worth all the work or money. JJ@BTP

[racer_99]

thanks doorslammer and everyone else for the info