big cam won't work with silent choice?
 

I was reading online that some of the larger cams say they won't work with silent choice exhaust, why is this? I never use the through the prop option, I always run the exhaust through the hull....Going to be doing a cam/intake etc....this winter and was wondering if I need to also replace exhaust. I don't mind doing it, should I just remove the silent choice (do I HAVE to?)?

Thanks,

Seth

LSA(lobe seperation angle) is probably too narrow/close and allows reversion. they likely recommend dry pipes. there are cam suppliers that can provide cam for your setup. i would get hold of bob madera, seems to be the man for cam setup.

Is a 114 lsa to narrow? How aggressive can I go while still running a manifold system with short risers? I don't mind ditching the silent choice and am currently looking for new manifolds, I just can't afford headers...

No that is good, 108 and 110 is narrow, I have been reading my head off on OSO and talking with CAM gooroo's on same subject. The answer I got was, with stock or short risers you want to limit your duration to 224 @ .050 and keep lobe sep at 114 or so, or you'll have a chance of reversion. I got a big roller going in my new motor and the boat had silent choice, so for me I have to ditch the silent choice and I'm going to go with Eddie's with the HP long risers. People say they work well and they are alittle cheaper than other aftermarket one. Just my 2 cents

The cam info I sent, is the max recommended. You would need to talk to Bob about your specifics. Honestly at the power levels you are talking headers are not worth much.

Call Marine Kinetics, it will be the best call you ever made, and he will tell you everything you need to match your set-up properly. Then you can gather what you don't have/need.

Brian I am going to call Bob tomorrow, didn't want to bother him on the weekend. I can't afford headers even if I wanted to, but I am considering ditching the silent choice and then trying to get some better manifolds and POSSIBLY long risers if I can get a good deal on them...

Seth

I understand, let us know what he says.

What are you calling a big cam ? what size motor ?

gen VI 502ci.

I know I'll sound like an idiot saying this but, I want to make as much power as possible with doing basically the following:

High rise single or dual plane intake
800-850cfm carb
manifolds with short risers (however, if I can score a good deal on long risers I will buy them)

AND an aggressive Hyd Roller Cam....

Seth

To clarify, I would like to make as close to 600hp as possible, but realistically I know I will probably end up around 500-540hp at most. I'm open to any and all suggestions. Going to call Bob tomorrow to talk with him specifically about my setup and see what he recommends as well.

Seth