Engine build questions

[Apestit]

I just bought a Jasper 5.7 marine engine for my 1996 2400 SCR today. The shop tech is pretty supportive regarding my choices of add ons. The original motor is completely shot and the people I bought it from were screwballs, couldnt find all the pieces for the motor. So Im starting from scratch.

1. Any concerns on Sierra Marine exhaust manifolds and risers?
2. At recommendations for intake, Ive been just looking at a Edelbrock 1409 marine carb, any recommendations there?
3. MSD ignition set up for Marine - comments?

I thought I should check before I just start ordering parts.

[mmwjr]

1. Any concerns on Sierra Marine exhaust manifolds and risers?

Nope used them before myself.

2. At recommendations for intake, I've been just looking at a Edelbrock 1409 marine carb, any recommendations there?

Is this a Vortec 8 bolt intake or older 12 bolt? The 1409 is a good carb and everyone I know who bought have been very pleased.

3. MSD ignition set up for Marine - comments?

I see no issues with this system.

[jrsick]

Have you decided on your cooling setup? Wet or dry joints? Closed cooling? This would affect which manifolds and risers you buy.

[mmwjr]

Originally Posted by jrsick

Have you decided on your cooling setup? Wet or dry joints? Closed cooling? This would affect which manifolds and risers you buy.

Great questions!

Adding closed cooling even if only a partial (engine only) is a good option. Either Wet or Dry Joint exhaust can be used with a full closed cooling system it's just a matter of what gaskets and fittings are required.

[Apestit]

Originally Posted by mmwjr

Great questions!

Adding closed cooling even if only a partial (engine only) is a good option. Either Wet or Dry Joint exhaust can be used with a full closed cooling system it's just a matter of what gaskets and fittings are required.

What I gather from this is that closed cooling is better, I can guess why now that I have googled and found out what it means (sorry Im a noob), can I assume the dry joint is better as well?

I will only be using this boat in fresh water, that I can foresee (lake Mead/Tahoe/Mohave/ and Havasu) but I do like the idea of a closed system and dry joint

Which of the best set up for longevity/reliability? And what brand?

[mmwjr]

I haven’t heard anyone complain about a particular brand of closed cooling but be sure the kit is rare for your engine package. Note some kits require an engine driven raw water pump but there are some designed for the Alpha Gen 2 pump.

Closed cooling also makes winterization easier.

Yes dry joint greatly reduces the risk of water intrusion from leaks.

[jrsick]

Both the wet and dry joints cool just fine. The difference is that the dry joint has more separation between the cooling water and exhaust which reduces possibility of water intrusion. Since you are buying all new anyway you might as well go with the dry joints.
You will also need gaskets between the manifolds and risers. The type gasket you need will depend on whether you are going with a closed cooling system or not.
Since you are boating in freshwater, whichever system you use will last a long time if you flush your cooling system after each outing. I boat in brackish water and flush regularly, and the water passages in my risers and manifolds look almost new after 5 years.

[Apestit]

Its a 12 bolt intake manifold, the mechanic says its an “old style vortec”. He also didn’t think that I would need the closed cooling system because I’d be in freshwater and did not recommend the dry exhaust manifolds because they get hotter than the wet. Does that sound about right because I’m going to have to winterize it as it does get to freezing however I also would like to use it in the winter as well

[mmwjr]

Originally Posted by Apestit

Its a 12 bolt intake manifold, the mechanic says its an “old style vortec”. He also didn’t think that I would need the closed cooling system because I’d be in freshwater and did not recommend the dry exhaust manifolds because they get hotter than the wet. Does that sound about right because I’m going to have to winterize it as it does get to freezing however I also would like to use it in the winter as well

While I agree a fresh water boat doesn’t benefit from closed cooling as much as a salt water boat winterization is so much easier with it as the engine is already protected by the antifreeze based coolant. I disagree with his comment that dry joint run hotter but the wet joint have been around forever and being fresh water should last a very long time.

[Apestit]

He also said its the “old style vortec” any intake manifold suggestions? I never got an intake with the engine when i bought the boat

[mmwjr]

I would get a dual plane intake marine rated. Also don’t one that is high rise else it might not fit under the engine compartment cover.