GLM 4.3 Exhaust (nutnboltguy)

[PITBoat]

Re your question in the closed thread - I've got a year on mine in freshwater. I bought them partly for convenience (everything you need comes in one kit) and partly for price, but I've got a <$5000 boat that I'd be pleasantly surprised to get 10yrs out of. Should I have that long left, heh.

The surface of the metal on the manifolds looks like Styrofoam (not melted hot enough?; I don't know how it's done), and there was a pinhole leak at the corner of one of them (very slow drip). Their customer service dept was good though, and sent me another one; which I've yet to install. The leak plugged itself with rust or who knows what and I'm not getting any water in the cylinders (so far...).

They fit well and didn't leak otherwise. I'm happy with mine to this point and the boat runs cooler with them than the rotten plugged up (probably original) batwings that were in there.

 

[Lou C]

Ok having read this....a suggestion....you can probably find a way to order the aluminum 90* exhaust pipes and hoses from GLM...if you can find the parts #s....then....get a set of Barr manifolds & elbows...and a pair of OE Volvo Penta gaskets...that will give you better quality and still save some money over the cost of the VP aluminum 90* exhaust pipes and hoses...the main concern with this style exhaust is always that manifold to elbow joint and gasketing. Doing it this way is a bit less risky, and a bit cheaper...my total cost with Barr+VP parts was about $1200, but in salt water you want the best you can get....

 

[Scott Danforth]

The surface of the metal on the manifolds looks like Styrofoam (not melted hot enough?; I don't know how it's done),

its called lost foam casting.

the form is a a foam shape that has the core sand pressed around. then the aluminum is poured in, it melts the foam and the part is made.

common aluminum casting technique on engines