Can any one tell me the depth in the hole for the pistons and volume of 1991 502 mag. motor. I am trying to figure compression on a head upgrade. thanks

Thanks for the info. to be more spefic i am looking at some
Brodix bb 2 plus heads with 100cc chambers on my 502 mags
i have upgraded everything except the heads need compression
seems like a good fix. What do you think would be the final
compression. thanks again

I deleted my other post casue the math was incorrect, sorry, hadn't had enuff coffee yet this is the correct way to do it

Just work backwards, stock compresion ratio is 8.75 to 1

The swept volume of one piston is
502.2ci/8 = 62.8ci or 1029.1 cc

so to find the combustion chamber volume

8.75 = (1029.1 cc +Chamvol) / Chamvol
8.75 * Chamvol - Cham vol = 1029.1
7.75 * Chamvol = 1029.1
Chamvol = 1029/7.75
Chamvol = 132.8cc

Since the stock heads are 119cc and the new heads are 100cc the new chamber vol will be
132.8 cc - 119cc + 100cc = 113.8cc

and so the new compression ratio will be

(1029.1cc + 113.8cc ) /113.8cc = 10.04 : 1

thanks alot for your help most appreciated. greg