Cam ?

Bryan76

Seaman
Joined
Apr 16, 2011
Messages
67
I got a 95 reinell with a 7.4bravo 1 putting thru hull exhaust on it and wanting to put a different cam in it to give it a better sound any suggestions?
 

Bondo

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Staff member
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Apr 17, 2002
Messages
71,082
Re: Cam ?

and wanting to put a different cam in it to give it a better sound

Ayuh,... The cam determines the operatin' range of the motor,...
Not the sound of the motor...

If ya want a lumpy idle, expect to Blow yer motor in no time...
 

Bryan76

Seaman
Joined
Apr 16, 2011
Messages
67
Re: Cam ?

So your saying all these boats i hear with a lumpy idle that there going to blow im sure there are some upgraded cams and might have to do carb,intake also thanks for your opinion
 

Bifflefan

Commander
Joined
May 27, 2009
Messages
2,933
Re: Cam ?

What he is saying is that a lumpy sounding motor is the cam "overlap". Thats what makes it sound good, but is bad for a boat as it can suck water into a cylinder from the exhaust. Look around for someone that builds boat engines and ask them what they use. If there are boats in your area that have a sound you like, ask them who built their motor.
 

45Auto

Commander
Joined
May 31, 2002
Messages
2,842
Re: Cam ?

On my 4 cylinder, I personally just mounted some big speakers (with a big amp) facing the back of the boat and play whatever exhaust sound I feel is appropriate to annoy people. Don't have to worry about reversion that way. I find that the sound of an idling 1500 HP top fuel motor really seems to impress people. :D
 

Bryan76

Seaman
Joined
Apr 16, 2011
Messages
67
Re: Cam ?

Thats not a bad idea but already have 3 amps,4 sets of comp. and 2 10s but whats the cam spec on that CD!!!!!
 

Bondo

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Staff member
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Apr 17, 2002
Messages
71,082
Re: Cam ?

So your saying all these boats i hear with a lumpy idle that there going to blow im sure there are some upgraded cams and might have to do carb,intake also thanks for your opinion

Ayuh,... Those big expensive Hot Rod barges with the lumpy cams are usually runnin' really long dry stacks, 'n wet tail pipes to prevent reversion...

Without the million dollar pipes,...
Ya, yer motor will be an Anchor in no time,...
 

StevNimrod

Petty Officer 1st Class
Joined
Dec 13, 2008
Messages
343
Re: Cam ?

+1 to what Bond-o is saying.

You can actually watch the water droplets walk UP the exhaust pipes at idle in some cases. If you know you've got a reversion issue, you can manage it (mostly in shutdown procedure), but it's still there and certainly doesn't help.
 

Volphin

Lieutenant
Joined
Jun 5, 2011
Messages
1,405
Re: Cam ?

Plenty of cams to choose from without all that overlap. The real question is what are you trying to achieve with the engine? What's the plan?


V
 

AZSenza

Chief Petty Officer
Joined
Mar 11, 2008
Messages
521
Re: Cam ?

I had thru hulls on my 17 foot 5.7 powered 4Winns. I KNEW i would suck water so I had a special "Come off plane procedure". Never had an issue but it was stock cam too...
 
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