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Old 02-10-2012, 06:12 PM
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Default GLM alum small block exhaust

any power improvement over iron mercruiser? can they handle salt? how much weight savings do you get?
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Old 02-10-2012, 08:07 PM
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Default Good Manifolds on a Budget

I run them on my 350. About half the weight of the cast irons.
Sound was improved and mph increase around 1 mph. This speed increase was probably due to weight savings and the fact that they are "semi tuned". The exhaust port runners go nearly up to the riser joint unlike the stock merc manifolds which are just a hollow cavern "Junk" "boat anchors". IMO

You can always add performance SS risers or just use the stock Merc risers.

The weight savings is the best part which if I remember is around 50 to 60 lbs for the both.

Last edited by Mariah212Z; 02-10-2012 at 08:09 PM.
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Old 02-10-2012, 09:23 PM
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I have a set of polished CMI e-tops with dry tailpipes i'll part with . I ran them for about 60 hrs. on my 383 . They also have the spark plug notches in the flanges for Trick Flow heads . Fresh water only . Just in case you may be interested .
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Old 02-11-2012, 08:01 PM
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Originally Posted by Mariah212Z
I run them on my 350. About half the weight of the cast irons.
Sound was improved and mph increase around 1 mph. This speed increase was probably due to weight savings and the fact that they are "semi tuned". The exhaust port runners go nearly up to the riser joint unlike the stock merc manifolds which are just a hollow cavern "Junk" "boat anchors". IMO

You can always add performance SS risers or just use the stock Merc risers.

The weight savings is the best part which if I remember is around 50 to 60 lbs for the both.
He's right about the weight savings. It's the most important part. I've ran them for 3 yrs now with no problems. Before that I ran Glenwood manifolds which were aluminum but did not have the tuned exhaust runners like the GLM's. I run them along with Imco 22" long dry risers. The combo flows well enough to get my Challenger to 78+ mph anyday. Best GPS 80.5 @ 6300rpms.
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Old 02-12-2012, 05:26 AM
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dry risers. open engine bay? what, the manifold water plumbed into a hose and overboard? so these are decent manifolds. came with the boat. 3 or 4 years old. i am guessing between these and the alum intakes there is about 150-200 lbs missing from back of the boat. and this is a tail-heavy little beast. when i owned it 5 years ago, water came in thru the side (think 4winns liberator) exhaust the one week i left it in the water jersey shore and wrecked both motors. now it has thru hulls pouring out over the glass platform. i wouldn'ta done it that way, but i got it back at a price i couldn't pass up.
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Old 02-12-2012, 08:16 AM
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Default Good Riser Option for the GLMs

Originally Posted by Mariah212Z
I run them on my 350. About half the weight of the cast irons.
Sound was improved and mph increase around 1 mph. This speed increase was probably due to weight savings and the fact that they are "semi tuned". The exhaust port runners go nearly up to the riser joint unlike the stock merc manifolds which are just a hollow cavern "Junk" "boat anchors". IMO

You can always add performance SS risers or just use the stock Merc risers.

The weight savings is the best part which if I remember is around 50 to 60 lbs for the both.
I would like to add these in the future.

http://www.keitheickert.com/p-13413-...imensions.aspx
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Old 02-12-2012, 01:45 PM
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imco has the same thing for about the same price. i don't think there is enough power gain to justify 1500+ dollars. prettier than black merc stuff though...
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Old 02-15-2012, 10:18 PM
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Nothing but good stuff to say about the aluminum manifolds... great weight savings and much better than the stock Merc stuff. I ditched the risers for IMCO units that I picked up used on eBay for a song. Best money I ever spent on the old Stinger.
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Old 02-19-2012, 09:02 AM
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Default IMCO Risers

http://www.imcomarine.com/cal_store/...nt-risers.html

What is the difference between the "A" and "SA" versions?
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Old 02-19-2012, 10:00 AM
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look at pics. one has extended piece where water mixes with exh like 4 inch merc risers. other has hose mount at end of riser.
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