502 build advise
#11
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I have builds similar to what you're looking for. You don't need blowers for 600. Your basic combo with 8-71s will be 800+. I have a comp custom cam. EQ heads with no port work just bowls cleaned up and a good valve job. 8.7:1 compression. Merlin intakes. 2 1 inch spacer and quick fuel 850s. 570 on the dyno in marine trim with wet exhaust. This was through etops. With some longer runners like CMI sweepers or eickerts these would have been 600 no doubt.
#16
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engine quest. Most find it practical to buy new heads instead of rebuilding since it doesn’t cost much more and you get more performance. Unless you have your own rebuilding capability, free time, and are really pinching pennys rebuilding doesn’t make sense.
#17
Crude
Did you buy them bare or assembled? Are you running stainless intake and iconel exhaust
what rpm you spinning and how much timing?Sorry for all the questions but I really like the simplicity of a single carb setup.
Did you buy them bare or assembled? Are you running stainless intake and iconel exhaust
what rpm you spinning and how much timing?Sorry for all the questions but I really like the simplicity of a single carb setup.
#18
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Bare. Had my guy go through them. Never buy assembled. Production stuff doesn't get the attention it should. I used ferrea super alloy exhaust valves. Ferrea competition stainless intake. .135 wall pushrods. Valve train is the key to longevity and reliability. 570@5900. Again. I know for a fact I'm choking myself with exhaust. Gonna be upgrading that next year and dynoing again.
#20
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Join Date: Mar 2004
Location: Denver, NC
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Another option is to call Bill at Ateco Marine. He has various upgrade packages for the 502 MPI. Mine are now 540's with Dart Pro 1 heads and made 630hp at 5300rpm's using the merc mpi intake and fuel injection system (MEFI 3). They look like stock 502 mpi's, but boat runs about 10mph faster and they idle like stock motors as well. Third year and 80+ hours on the motors and very happy.