merlin oval port heads question
 

I have a 502 gen VI block, 9.0-1 comp, good rotating assembly, lightning headers, air gap mainifold, crane gold series race 1.8 roller rockers, roller lifters, crossover style cooling, mystery cam (?) and merlin 264cc oval port heads with 2.25 and 1.88 valves, incolnel extreme duty. the boat is a baja 232 boss, approx 3900lbs, runs 70 gps at 5000rpm with a 24p four blade mirage plus prop.

Im looking for more power, what can these heads handle cam and flow wise? I would like to hit the 500 horse number with just cam and carb upgrade. Is this possible? Or do I need some better heads to achieve this number? thx in advance


Derrick

Re: merlin oval port heads question
 

The heads need to be ported. The intake runners are too small. The airflow will increase with added volume. The flange should be about 2.1 inches tall by 1.75 wide. With a .650 lift hydraulic roller, you should make well over 500 hp.

Re: merlin oval port heads question
 

The heads will support that kind of power as is. Matched camshaft should put you their no problem.

Chris

Re: merlin oval port heads question
 

.650 is a lot of lift combined with 1.8 rockers.I don't think you want to go over .580.