I was thinking back to when I used to work on boats with my friend's parents, and I remember the unique exhaust manifold style that these boats had. The manifolds usually were boxy in shape, and placed the outlet sticking straight up or down. Almost all of these had extra outlets on them as well, which could be used for waste gates if need be.

These manifolds number in the plentiful, and can be had pretty cheap new. What are your ideas on this?

 

Looks like a normal marine manifold with a water cooled turbine flange. Will a non-water cooled turbine match up to it?

 

that looks interesting.... and it looks like it would hold the weight of the turbo.... cool!

 

you don't say

 

I had those same manifolds on my small block boat, and had wondered the same thing. IIRC, the port that comes out in front (or behind) the riser (that looks like a turbine would mount to) had a 1/2" NPT fitting with a high heat rubber hose that went to the sea water cooling system, and was pushed out by exhaust pressure/gravity. They were mounted like the picture on the right while in the boat, and had an adapter that bolted to the riser and made a sharp loop back down to the bottom of the boat and out the back. Also IIRC, this was to heat the water before going to the cooling system, so the engine would run at a decent operating temp due to the constant flow of sea water, much cooler than a "fresh water cooling" system that used a radiator that was water to water (heat exchanger it was called). I had toy'd with the idea of putting a heat exhanger on it and making an adapter to mount turbos to those same manifolds, since the 305 would do maybe 12mph according to my hand held GPS at 2500rpm's, and would hardly get the 5000lb boat on a plane (24' Wellcraft cabin cruiser that got destroyed in Wilma )

 

Theres a place here in Florida that make these. Following this design, good turbo headers could be made. The ones in the picture are way too expensive to use for something like this though...(think, $2000 a set, 100% stainless steel).

Because these are much shorter in height than if you used blog-hugger headers (flipping upside down and all that jazz), they could be not only easier on the eyes, but much more sturdy IMHO.

Actually, there is a manifold like my 2nd picture above going for $10 on ebay new...

 

Good stuff. I never got into the boats, but had fun modifying the stand-up Jet-Skis. Having an infinite supply of cold water can make a lot of HP.
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Those manifolds look nice, but most of the turbo people are trying to do it for cheap. A stock set of GM or Ford manifolds with a days worth of fab/welding will support 600 HP. I think that is why most turn to stock car manifolds, weld els, or thin tube. A set of stock manifolds will get the height lower than the ones in the pic.

 

HMmm, I've messed with ski's a few years ago. Shaved the heads, ditched the oil injection etc (701cc 3 cyl Yamaha Wave Raider). Wasn't using it enough to justify payments and solt it.

Yes, the manifolds are fairly expensive. Cheapest I was able to find was $300 IIRC (one side had rusted out), and this was for only one side.

BUT $10 on e-gay would be woth trying out.