I have an 18ft light weight jet boat. The motor is a 454 bored .30 over,9.5-1 compression,torker2 intake,holley 750vac sec,large oval port heads(ported),full roller rockers,3 angle valve job,over the transom headers,hei ignition,msd 6al ignition box, and the motor is balanced and blueprinted.
I narrowed the cam down to 3 choices. Someone told me not to go over 235 duration @.50 on my cam because my motor will never see the rpm's to make the horsepower. Is this true. I am planning on purchasing cam,springs,lifters and pushrods to match my cam.
These are the specs for the 2 cams I narrowed it down to.
Choice #1- This cam says A/B impeller,9.5 compression and performance use.The rpm range is 2500-6500,duration @.50 244 intake/254 exhaust,(.570 intake/.575 exhaust valve lift), and 112 degree lobe seperation on intake/exhaust.
Choice #2- This cam says good pleasure use and good economy. The rpm range is 1700-5700,duration @.50 222 intake/226 exhaust,(.525intake/.525exhaust valve lift), and 110 degree lobe seperation on intake/exhaust.
Choice #3- This cam says A impeller,needs improved intake, and likes headers. The rpm range is 2000-6200,duration @.50 234 intake/237 exhaust, (.564 intake/.566 exhaust valve lift), and 112 degree lobe seperation on intake/exhaust.
Those are my choices. I got these cams from the comp cams list.I noticed that the lobe seperation is a lower degree(112,110,108 etc) as the cam gets bigger. Does this effect the sound and idle? Could someone please explain this to me? I am so lost as to whats good for my boat. I want the best out of those 3 cams. I want a real rough lopy idle. I am also looking for a cam that can give me a real beefy sound. I would appreciate any help on this guys. Thanks 396--out!