GLM risers and manifolds

C

Carvervirgin

Member
Member
Joined
Jan 4, 2012
RO Number
32836
Messages
323
I am doing some research on replacement manifolds and risers. Does anyone have an opinion of GLM brand aftermarket parts?
 
I don't have an opinion...but I've heard that GLM are inferior to Barr and Osco brands-something about flashings in the castings.
 
There could have been those problems in the beginning. Let us know their quality if you get a set.

I got aluminum manifolds from GLM to save weight. No problems so far but they've only been on about 25 hrs.(doing an engine break-in)
 
Remember GVP? He/Geo wanted me to use Sierra. I must be in the world's saltiest water, but in three seasons, they clogged. And that was with flushing every trip. Geo wanted me to get the benefit of Sierra's design, which makes for larger exhaust passages, and therefore slightly larger overall size. That was OK, perhaps the boat ran a little better, just a little more difficult to change sparkplugs in the SBC engine.

If you're in fresh water, and stay there, I'd think most any manifold would work OK and last OK.

Oh, after the Sierra system clogged in 3 seasons, went with MerC's ceramic-lined ones. At probably twice the price, they're clogged now, 5 seasons. Most people say 3-5 years on cast iron and 6-8 on ceramic. I must have the saltiest water...
 
Heh! Heh! Heh! Don't you remember when Geo posted the findings about the salinity and water temps affecting cast iron. The Gulf and Florida having the highest water temps and salinity.
 
I've switched back to the OEM.. Tried the Sierra/Aquapower/etc. and the OEM seem to hold up better..
 
I'd like to have a reading on how many have used GLM Aluminum and if they offer longer service, as well as the weight reduction. It seems MerC has tried pretty much everything incl. aluminum and stainless and gone back to cast iron.
 
The GLM parts I am looking at our cast iron, not aluminum. Thanks for all the feedback.
 
GLM claims to have improved exhaust tuning along with a more precise "lost foam casting" technique.

Again, in fresh water I'm satisfied 'most any manifold would last for years.
 
I know there were some reports years ago of poor finishing on the mating surfaces of the GLM units. The last set of manifolds I installed on a Mercruier were Sierra. Even with those, I used a flat drawfile to clear any surface slag or imperfections and did come away with a little 'smooth-filing.' So, I guess that with whichever brand you use, use a flat file on the mating surfaces first. As to aluminum manifold and risers, I had heard of some sealing problems after a while because of different coeffcients of expansion of the aluminum manifolds and the cast iron of the blocks, but I have no first-hand experience with that. Hy
 
I welded the water jacket of my aluminum manifolds so the FWC system is totally sealed. The base of the SS risers I made don't have openings for the water jackets so there's no way to leak water into the engine...short of busting a weld.
 
You must log in or register to reply here.
Back
Top