Aftermarket Exhaust Manifolds

[CBLavey]

I'm thinking about upgrading the exhaust system on my 6.2MX Mercruiser. There are so many choices - Eddie Marine, IMCO, Gil,Dana, CMI, Lightning, and more so I'm looking for some input based on anyones personal experience with a system that they have used. Real world horsepower, speed gains, etc would be appreciated!:cool: :cool: :cool:

[summerlove]

I picked up 800 rpm and about 6-7 mph by adding thru-hull exhaust and switching over from stock merc exhaust to IMCO Powerflows. Boat is about 3500 lbs - 4000 lbs and is running a 330 HP 454.
Hope it helps.

[carreraboat]

I have a freind that is selling a set they are like new he going with big block power and wants to unload them

[bigq]

unless your going from through hub to through transom don't waste the money. If it is part of other added features the go with the lighting headers. I heard the Dana products are good also.

[CBLavey]

Thanks for the info. I'already have through transom exhaust. I'm swinging a 22" Bravo Four at 5200RPM with a moderate load - full fuel, four adults, gear. I think that a good exhaust system will allow me to swing a 23" - 24" pitch at the same RPM.:cool: :cool:

[CBLavey]

Originally posted by carreraboat
I have a freind that is selling a set they are like new he going with big block power and wants to unload them
Thanks for the offer, but I think I'd rather buy new for the sake of a warranty.:cool:

[Havasu Hangin']

I think the aftermarket manifolds (like EMI or Imco) are good up to 500HP. After that, I'd consider headers.

[Trash]

I'm not sure you're going to see any advantage using aftermarket exhaust manifolds, except perhaps, a lighter wallet. Seeing as how you have through-hull exhaust, your engine is going to breath about as freely as it can in this stock configuration.
I'd try a bigger wheel just for kicks and see what happens. It's a heck of a lot easier that swapping out manifolds.

[Desert Rat]

Originally posted by carreraboat
I have a freind that is selling a set they are like new he going with big block power and wants to unload them
Whats he asking for them?

[carreraboat]

i will ask

[flat broke]

I thought I remembed seeing a set online that looked like Gil units, and after doing a little digging, I found em.
http://revolutionmarine.com/images/manifolds5.PDF
No decent data on them, but at least they have dry riser joints and individual runners. And at $995 not a bad deal even if doing a rusted merc swap out.
Chris

[gnarley]

Originally posted by flat broke
I thought I remembed seeing a set online that looked like Gil units, and after doing a little digging, I found em.
http://revolutionmarine.com/images/manifolds5.PDF
No decent data on them, but at least they have dry riser joints and individual runners. And at $995 not a bad deal even if doing a rusted merc swap out.
Chris
I read about these also and wonder how they flow as compared to other more expensive choices???

[carreraboat]

hey desert rat left you a pm