markku4444

I have 2 engines that i am going to build,they are 540cui,cam specs.@050 Int258 Lift.714 Exh.266Lift.714 Lobe114+4.They are solid roller cams.comp is 10,5:1 with 119cc heads,Team-G single plane intakes,1000cfm Holleys,everything is internally balanced.The question is what heads should i use, should i go with 122cc heads to lower the comp,they have never been assembled,the119cc heads i had was used to 2 other engines,so i need to buy 2 sets .And what kind of HP/TQ can i expect???

cubicinches

How did you decide you wanted to use that particular camshaft, when you don't know what cylinder head you're going to use?

markku4444

I had these cams custom made by Howard for a 14000lbs Navy seal boat i had,the cams was made for merc 088 heads but as i told donīt have the heads anymore,so i figured there is better heads for these engines.

PatriYacht

Those cams are going to make for a difficult, high maintanence set of engines. Even with a good small runner head like an AFR 315cnc you're going to have a power peak around 6500 rpm. Although it would be about 800hp. You would need to build the entire engine to withstand those revs. Good internals, no Eagle crap. Jesel shaft rockers and good springs in the valvetrain. A top notch oil pan from Stefs or Canton with a good oil pump and windage tray. Leave the compression at 10.5, you're going to need all you can get even if it means mixing in race fuel. Is this really what you're looking for? If not switch out the cams but keep the AFR heads. They're the best for this size marine engine.

47EXCALIBUR

AFR 335 CNC or Dart 335 CNC,,,, would definitly put shaft rockers in (Jesel or T&D ) that cam choice you have is to big reguardless of how much the boat weighs... 240 248 620 632 on a 114 is what you need ...try and lower the comp to 10:1 if you can to run the engine safely on 89-93 octane depending on how much timing you set the motor at... start at 34deg...expect 650-700hp and RELIABILITY

searaycer

I am building a 548 right now and have 345 Merlins done up by Ron Potter.

SickSation

Talk to Bob Marada at Marine Kinetics. Hes a bad a$$. We went with AFR 305 on my 548.

http://www.marinekineticsonline.com/

fbc25el

I have a 540 with 9.7 cr. crane hyd. roller cam and AFR 315 heads. Verry happy with the combo.