NHGuy

This is bench racing/ imagination but.
Why not look at the closed cooling and jacketed exhaust of the Mercury 1350/1650 engines for inspiration? I'd expect that with those, the exhaust manifolds are hotter than straight lake water cooling. That would allow more exhaust heat transfer to the turbo than cold water exhaust jackets. You would have to use exhaust manifolds that can take heat though.
If you blanketed the turbocharger housings and placed some temperature probes inside the engine bay during development you could decide just how much engine compartment air movement would suit your setup. Maybe start out by driving it with no cover. Then add parts to the cover til you like how it works. You will want temperature and pressure probes all over the place.
Your intercooler will probably need to get the cooling water first, then whatever it passes through could go to the heat exchanger. If it's too hot they can get separate cooling water feeds.
I would love to build something like that but I think I'd try to do it with a bigger LS engine.
On the LS there are not as many marine exhaust choices though, so that could be a problem.
Once you have your design you can do the final engine cover with the air movement you need.

88sonicSE

Well my thoughts were something along those lines.. I use thermostats in my motors, so taking the water from the engine into the exhaust jackets would be around 160. I’m thinking if I plug a bob into the exhaust jacket, and run a hose to a bob on a jacket around the exhaust housing of the turbo, then another bob opposite to run the line to the tip, the water would be hot Enough getting into the jacket. I would have to weld a partition into the jacket so the water doesn’t just stay in side and swirl around. Intake and outlet ports would be right next to each other, but on opposite sides of the internal divider.

CDShack

I'm installing some Gentry Engineering Twin Turbos right now. Carson Brumett is the Gentry guy. (626) 792-6410. Super, top-level turbo guy (and nice guy). In the end, 10 psi of boost at the head doesn't know if the turbo was water-jacketed, blankleted, supercharged or procharged. For safety and proper packaging, definitely need water-jacketed turbo exhaust housings in an enclosed area, particularly if you have 4 of them! There are several new makers of water-jacketed housings, there are used sets of Gentry and Banks if you can find them, or get new Gentry's from Carson, but be ready for sticker shock. In my research, I've even seen some guys fab up stainless "water cooler" that go over regular exhaust housings, so the options are endless as your imagination and wallet.

I was lucky enough (after 2 years of searching) to find a matched set of Gentrys from intake to exhaust tails, but they are getting rare. Water leaves the exhaust manifold, into the exhaust housing, over to the double-walled exhaust tail, and out of the boat.

Good Luck! These are my first ever turbos, kind of excited to see what happens!

SB

iTrader: (1)

Few people have done twin turbos successfully here, over the years.

Check300 rings a bell in my mind. Do a search.

Ad far as 10psi at the head doesn't matter how it got there ? Huh ? Sure does. And just, or more, important is when it get's there.

Keith Atlanta

I didnt think it was possible to create a secondary cooling method. The turbo housings crack dont they?

Cerberus66

Turbo option is amazing. Its obvious they work, MERC RACing uses them as the biggest power maker. On modern two valve v8's they are great but mutli valve they really rule. Putting together a compact water cooled and oiled package is very complicated and it is expensive because the equipment to do it is all custom. But then again I put a metric 496 mag ho and im making 1300hp with a hopped up Procharger. AS I SIT HERE AND THINK ABOUT IT. i ALREADY HAVE A PLATFORM FOR IT ON MY MOTOR. I have the block ECM system I would just need to fit a couple of turbos with water cooling.....where would I introduce water into the exhaust jacket with torching my engine room. How would i use the intercooler. 588 needs lost of exhaust. rightnow i produce almost all my power very low in the rpm scale.

Trash

Turbos are done all the time. Checkout BoostPower or Carson Brummet. Problem is few do it so the price is reflected accordingly.

88sonicSE

I called both.. no one answered. No one has returned a call.

CDShack

Hi SB. I respect your motor skills, but I think you are trying to make this too complex. My answer was after all the charge density, speed and velocity, volumetric efficiencies were calculated and debated, etc etc. -- if there is 10 psi of boost at the valve ready to go, that cylinder doesn't care where it came from; be it a roots blower, turbo, or ProCharger. When we drag raced flatbottoms, it was "Boost is boost".

Now more to the point; the issue was raised whether cooling the turbine exhaust housing adversely affected the exhaust boost efficiency to the point you might consider not running a full water-jacketed turbo housing in your build philosophy. My reply was intended to express my belief that if a wet turbo and a dry turbo both produced an end product of 10 psi boost, all else being the same, the motor doesn't care where that 10 psi came from. Safety has to be NO.1

For years I had qualms about turbos too, in fact, it kept me from attempting to live with one up until this point. With the availability to the public of better and better computerized fuel and spark management, and the success of the long line of turbo Merc Racing engines, I thought I'd give it a try too. We're supposed to be having fun, so right now, turbos seem fun. Ask me later, you might get a different answer! LOL!

CDShack

Text Carson at that number I gave you. He'll get back as soon as he can.