Replacement Manifold/Riser opinions

[Jvoisel]

Looking for opinions on which replacement manifolds/risers to go with on my Mercruiser 4.3. I will be converting from the one piece manifolds to a two piece setup.

I know OEM parts will be most recommended but looking to do this on a budget. The boat is raw water cooled, and will be used in pretty much every type of water; fresh, brackish, and salt water. Everything will definitely be flushed each time the boat is used and never left in the water over night.

I like the idea of aluminum manifolds for the weight/performance, and the HGE/Barr combination I listed below actually comes out to be the cheapest. Just not sure about being raw water cooled and using it occasionally in salt water.


Here's what I've come across so far:

Complete Barr Marine Cast Iron Conversion kit for $885 shipped
http://www.michiganmotorz.com/mercr...d-barr-marine-conversion-19872001-p-3507.html

HGE Alumimum manifolds/risers, and Barr elbows/bellows for $660 shipped
http://www.michiganmotorz.com/mercruiser-aluminum-exhaust-manifold-package-19872001-p-881.html
(Barr Marine elbows and bellows found on another site, piecing this together)

GLM Cast Iron Kit for $735 shipped
GLM Aluminum kit for $875 shipped
I've read a lot about having to machine down the mating surfaces on the GLM manifolds, which isn't a big deal for me to do

I've also found HGE dry joint manifolds/risers, and Barr elbows/bellows for $1000
http://www.ebay.com/itm/Manifold-Ex..._Accessories_Gear&hash=item35da980079&vxp=mtr
(Barr Marine elbows and bellows found on another site, piecing this together)

 

[alldodge]

Since your going to be using it in salt then use cast iron

 

[redneck joe]

why is that? I'll probably need new this year and have been contemplating going other than cast iron. What are problems with using other? I'm not in salt but still wondering.

 

[alldodge]

why is that? I'll probably need new this year and have been contemplating going other than cast iron. What are problems with using other? I'm not in salt but still wondering.

Salt is hard on everything and will destroy aluminum in very little time if not coat with something to keep the salt away. Iron manifolds will last 5 to 7 years being used in salt all the time, and more if it is not full time. You wouldn't use aluminum anodes in salt water because they would not last, but would use them in fresh. Coated aluminum does last longer but the surfaces which are not coated. This is also a reason your shouldn't use aluminum heads on an engine with open cooling system in salt

 

[Jvoisel]

I've talked to a local marine company that sells glm, and they say that they sell more aluminum than cast iron manifold kits.

They claim with proper rinsing and keeping good anodes in the manifolds, I won't have any issues with the salt water. Just looking for some more first hand experience

 

[thumpar]

The dissimilar metals may cause and issue.

 

[philbullet]

I've been running a 470 for years now in salt water/brackish and haven't had any trouble and that's a alum. Block with iron head, But that's also with antifreeze running with a heat exchanger.
I guess Ian gona find out soon because Iam waiting on my aluminum manifold and elbow's right now for my 4.3 v6 i just converted.lol
I plain on putting a heat exchanger when I find a good deal on one.

 

[Tail_Gunner]

I've talked to a local marine company that sells glm, and they say that they sell more aluminum than cast iron manifold kits.

They claim with proper rinsing and keeping good anodes in the manifolds, I won't have any issues with the salt water. Just looking for some more first hand experience

You need to find a new marine company...sorry about the misinformation just..... Google aluminum manifolds salt water ...ill do it for you..

https://www.google.com/?gws_rd=ssl#q...clubsearay.com