GLM Manifolds Quality

[myredchevys]

I will be replacing my manifolds and risers this season on a 4.3 L V-6. It seems some have had fit problems with the glm units and others praise the quality and fit. I read Bond-O's post on the glms (I hope he will chime in) saying they were of good fit & finish but read a later post were he had to rework them because of a leak. Can't figure out if they are ok or not use -thanks all.

 

[Don S]

Re: GLM Manifolds Quality

They have issues still, but they are supposedly replacing the bad ones. Hopefully you don't loose your motor finding out.

 

[neilmw]

Re: GLM Manifolds Quality

just fitted GLM on mine and had no problem with the fit, seem to be working fine but havent run it that much yet so will keep my fingers crossed.

 

[liquidlew]

Re: GLM Manifolds Quality

I got GLM manifolds and risers for my 4.3 this last Feb. The risers looked fine but the manifolds were pretty messed up, the 2 plugs on top next to the water jacket openings were not screwed in far enough for the risers to sit flat, the water jackets looked uneven, not a perfect rectangular opening, and the mating surfaces were not flat. Got them replaced, just got them last week and they look perfect, no visible flaws like the previous ones. I also noticed the first ones had Made in China on them, the new good ones don't have that anywhere on them so that should tell you something. Don't know what they are doing over there. You can save $ and roll the dice but if you don't want a possible headache, I'd go OEM.

 

[Mkos1980]

Re: GLM Manifolds Quality

I'd had Sierra before and they were stamped CHINA on them as well.

 

[bruceb58]

Re: GLM Manifolds Quality

I only use OEM manifolds and risers.

 

[qystan]

Re: GLM Manifolds Quality

Merc now uses the dry joint exhaust.

From what I saw, the water now passes from the manifold to the elbow/risers via an external path rather than the slots at the joint - you will definetely want to use these.

I believe they can be used on the older engines - strongly recommend to check it out and use it if possible.

 

[myredchevys]

Re: GLM Manifolds Quality

Bond-o you got a take on this- interestied what mods would have to be done to convert to a dry-joint exhaust

 

[newport dave]

Re: GLM Manifolds Quality

You can replace a wet joint system with a dry joint system with very little or no modification, as long as your starting out with a small block Mercruiser, and are willing to pay the extra $250 to $400 over what a wet joint system would cost.

Big block (454/502CID) Mercruisers can be converted to use an aftermarket dry joint system, or even the OEM dry joint system from a 496/8.1. Your likely to need more modifications with one of these systems, but it certainly could be done.

 

[TollyWally]

Re: GLM Manifolds Quality

please excuse my ignorance, can someone tell me the difference between wet and dry joints?

 

[Mkos1980]

Re: GLM Manifolds Quality

please excuse my ignorance, can someone tell me the difference between wet and dry joints?

Dry joint means no water flow from the manifold through a gasket into the riser. Its blocked off. Dry joint uses a hose from the manifold to the gasket. 100% leak free way (For gaskets at least)

 

[Bondo]

Re: GLM Manifolds Quality

Ayuh,......

A Wet Joint manifold passes the water up thru the ports cast into the manifold,+ riser.....
A Dry Joint set up has No Ports cast into them,+ the water is routed thru Hoses to the riser......

You can see the water ports quite clearly in this picture,...
On a Dry Joint manifold, there's only the large exhaust hole in the top of the manifold....

Those manifolds were about .005" low on the exhaust port, or about .005" high on the outside edge of the gasket surface,....
They've been milled down about the same amount,+ are Good and Flat now....

I put the new SSteel risers on last night,+ will mount them to the motor 1 night this week.....