Ok guys, I want valid technical reasons why I can’t put turbos on a big block. on my boat. I’m not looking for go with prochargers, or any other week just don’t do that’ answer. Hard technical reasons or obstacles that need to be overcome

There is only one obstacle, keeping the turbo housings cool enough so that you don't burn it to the water line

water cooled turbos should do the trick in my mind...they are getting more and more common in automotive applications. I’ll need to get some numbers on temps...

The problem you have is that with water cooled exhaust and water cooled turbos, you are loosing so much of the exhaust force due to cooling. Your best bet is to use insulated cast iron manifolds with insulated turbo jackets. But then you need to ventilate the hell out of your engine compartment to protect everything else. The cast iron manifolds will grow less and hold heat better.

Well the exhaust gasses won’t be cooled until after the turbo... water going through the impeller will destroy it..My thought was dry exhaust to the turbo, and welding up the holes internally for water draining. Then weld a couple fittings to bypass the water around the turbo to the tips. Then just having the cooling water run through the water jackets inside the turbo casting that re already there... I got plenty of ventilation holes I can actually use a fan to force air through on the side, plus I have goo gobs of room in the bilge.. I could probably have an 8/71 blower on the engine without cutting holes in my hatch.

Well the exhaust gasses won’t be cooled until after the turbo... water going through the impeller will destroy it..My thought was dry exhaust to the turbo, and welding up the holes internally for water draining. Then weld a couple fittings to bypass the water around the turbo to the tips. Then just having the cooling water run through the water jackets inside the turbo casting that re already there... I got plenty of ventilation holes I can actually use a fan to force air through on the side, plus I have goo gobs of room in the bilge.. I could probably have an 8/71 blower on the engine without cutting holes in my hatch.

Do you have water cooled exhaust housings? (Water surrounding the entire exhaust)

my motors are out, and I’m redoing everything..I understand there are dry headed setups, where there is a jacket around the tube, then I would bypass around the turbo, and connect the water to the tops to go through the transom

You need to cool or blanket the housing. Not just circulate coolant through the center cartridge for the bearings. Far from impossible, but not very easy either.

I have no input to your Q, but saw this the other night.

https://www.racingjunk.com/Turbos/18...&from=search#3