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Opinion needed on a 496 cam

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Old 04-19-2011, 06:23 PM
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Default Opinion needed on a 496 cam

This is a friends motor in a single engine 26 foot sleekcraft
The motor started out as a 365 mag motor, upgraded to eagle 496 ratator.
compression 10-1
ported rectangle steel heads (really opened up!)
single plane intake
850 holley carb
full MSD ignition

The cam they recommended was as follows
Hydrolic roller
610/610 lift
230/242 duration
112 center

What do you guys think?
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Old 04-19-2011, 06:37 PM
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What exhaust and do you have flow numbers on the cylinder heads after the work?
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Old 04-19-2011, 06:48 PM
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no flow number right now
The exhaust is the older CMI two piece tube top. No silent choice
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Old 04-19-2011, 07:49 PM
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Who's they ?
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Old 04-19-2011, 07:52 PM
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Originally Posted by jeffswav
Who's they ?
That made me chuckle. Good question.
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Old 04-19-2011, 08:15 PM
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The guy that said it ran good in a car!
Which made me chuckle
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Old 04-19-2011, 08:19 PM
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Another quesion, what are your HP goals and how many RPM's are you planning to run?

I just read your post over again. I see its your buddies boat, tell him to call Bob RMbuilder. The car guys dont know s--t about boat engines.

Last edited by jeffswav; 04-19-2011 at 08:33 PM.
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Old 04-19-2011, 08:50 PM
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Dude! I told him to call Bob, he wouldn't listen.

Always talking 600 HP area at whatever RPM it takes.
The previous non roller setup ran at 56-5800

I'd rather see it down in the 52-5400 area. Something with more torque, especially with a single engine.
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Old 04-20-2011, 09:35 AM
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Compression ended up more like 10.25-1
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Old 04-20-2011, 11:49 AM
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Let me start by saying I shouldn't say what I'm about to say, are we clear!! Since your friend has no interest in listening to an expert he clearly is smarter than everyone. If he was spinning a mag motor 5800 WOT he was making noise not power, that cam can't support it. A hydraulic roller combo should not turn above 5400 or you risk valve float. The cam he suggests is not large enough for 5800 rpm and needs to be mechanical roller anyway for that rpm. I think what he really wants is a boat he can talk about. He should put a large duration camshaft with a 108 LSA so he has the most knarly idle in the marina, spend his money on a really cool sticker to put on the engine that says 600 HP or heck even more if he wants. The boat will likely barely come on plane and run terrible but it will sound really cool and show great when it is broke down. I'm sure he doesn't need a 3X18 oil cooler, or a quality oil pump, or upgraded fuel system either but it's a suggestion. Let me know when the maiden voyage is, I'd like to bring a cooler and a chair to watch it get on plane. Good Luck.
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