502 Mag camshaft
#11
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Great thread. I read on here somewhere that the GM steel heads are good but you can gain some fairly easy HP by doing some head work. There is room for improvement and the heads are good enough to warrant it. Wish I could find the thread.
Last edited by Pismo10; 09-13-2007 at 07:53 PM.
#12
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Hey guys getting ready to freshen my 91 502 mags (carbed), have 700 hours thinking the time is coming. Have read many of the previous reccomendations on combinations of components etc but curious of the cam specs that are in it now, also are my heads decent, with valve job/ porting. I would not be looking to make big horsepower just want to enhance while I am in there. I am economically limited but want to do it right. thanks
Also, you were asking about the heads---the Merc 502 Mags came with a stock GM rectangle port head---have them checked out or you may even want to replace them because they are prone to cracking between the seats. It happens randomly and it happens a lot! So, before you spend money on any head porting, etc, you might want to think about that.
The 502 Mags came with all forged parts, but no roller rocker arms. What kind of exhaust system are your currently running on your boat with your engines??? Who wil be doing the machine work and assembly of your engines?
Last edited by KAAMA; 09-14-2007 at 10:47 AM.
#13
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Thanks guys for all the good input, Inspector I will ponder the cam you have, also RM builders, Kamma I am currently running stock exhaust but want to move up wont be anything real outrageous though revolutio/stainlessM. havent started calling machine shops yet, any suggestions thanks again. Randy