The manifold/riser debate...again.

[cmezzino]

I had been reading through previous discussions on the debate between Barr, OCSO, Sierra, GLM, HGE, and OEM exhaust manifolds and risers. The threads were years old, so I’m wondering if any of these products have improved or declined in quality or reliability versus the others in more recent years?

MOD EDIT - UNACCEPTABLE You must be kidding! Stay civil, we have kids visiting the forum.

But again, the thread was years old. Does anyone have any more recent experience? And does the concern involve all applications? What I mean is that the product in general is crap regardless if it goes on a Mercruiser or Volvo-Penta, etc. (mine is VP).

And lastly, would anyone think that a set of good, clean used OEM should even be considered? I came across a set of freshwater used (150) hours and wonder if I should even consider it.

 

[stouchton]

I was in the same predicament as you, particularly with the age of the opinions on GLM.

I am in the process of replacing the manifolds and risers on my twin 4.3GXI.

I deal with products produced in China - so I know first hand they can do excellent work if you want to pay for it......

Well, the GLM castings are superior to my original 2004 Volvo Penta castings. By this, I mean the casting accuracy and quality is better (flashing, distortion, finish). Many folks warned me about the old GLM having defective mating surfaces. The mating surfaces on mine have been cut with a fly cutter - they are perfect.

They are very well painted. No need for any repainting as others have experienced recently with Barr.

I only had a choice of Volvo Penta or GLM since I have the tall riser (11.3").


My risers and manifolds lasted 15 years. Just this past fall I found a smidgen of water in the oil, and found dampness at one exhaust port. However, my boat was High and Dry stored from 2004 to 2017 - which most definitely probably added to the life of the riser/manifold. Not sure run time hours has much to do with it (I only have 450 hours).

I found the quality of the new GLM risers/manifolds to be top notch on the outside. I can only look so far inside (with any of them), so I am hoping what I see on the outside is representative of what is inside. As far as I can see in, the castings look perfect.

 

[cmezzino]

That's very interesting, as your assessment of GLM appears quite different than the ones I read before. But, I'm glad you seem to have had a good experience with them. I wonder how one would know whether the GLM's they receive are "older" or "newer" with respect to the quality?

I also note that GLM's website has far more technical data on their design and performance when compared to OEM and other aftermarket brands.

 

[Scott Danforth]

Barr is one of the casting houses for VP. Get either OEM, Barr or Osco

Plenty of recent threads with Good Luck Marine manifolds, including casting defects that normal casting houses would have remelted

 

[stouchton]

I do not want to discount anyone's bad experience - only relating my own experience. I bought 4 manifolds and 4 risers for 4.3 liter last month. Externally, castings are of excellent quality with proper machining of mating surfaces.

I have used a bore scope to look inside - which is really not easy to do... The quality of the casting I have seen internally matches my expectation from seeing the outside. It COULD have issues I cannot see, just like any other casting. So I really will not know for sure till they are installed and running. And most likely I will need to loosen manifolds from block and check.

I purchased GLM under the pretense they improved quality, and I was planning on returning if I was disappointed.

I have had some bad experience with OSCO (leaking new manifold on a Merc 265), so I am kind of nervous as to how any of the manufacturers can guarantee the quality of the casting.

 

[QBhoy]

Only issue I’ve ever had was when I stupidly bought Sierra risers and left the original manifolds. Trying to mate them together wasn’t great. I should have just bought the full set together. The castings just didn’t want to seal or mate with each other easily. Ended up just buying the manifolds too. No issues fitting

 

[Lou C]

I installed a set of Barr V6 manifolds + elbows on my '88 OMC to replace the NLA original one piece batwings. The fit was perfect, the only issue I would say is the paint is thin it needs an extra coat to prevent corrosion in damp climates like ours.