Carver Owners Forum

Hi fellas,
I have twin Volvo Penta 740b gas engines in my 1992 Carver 36 aft cabin. I managed to fresh water cool the engine itself, but cannot find the thermostat housing to cool the exhaust manifolds. Has anyone managed to fresh water cool the exhaust manifolds on these engines?
Thanks

When it comes to fresh water cooled engines, they can either be a full or half system. Full means the manifolds are included in the fresh water cooled system…half mean they are not. You have a half system. Google fresh water cooling and you will see what needs to be done to have a full system.

I'm not understanding the "cannot find the thermostat housing" part, and how that relates to the manifold question. If the manifolds have two or more ports (plugs) to run the coolant through then you can do it by modifying the hose arrangements.

But you also need to install a block-off plate between the manifold and riser.

km1125 wrote:I'm not understanding the "cannot find the thermostat housing" part, and how that relates to the manifold question.

Agree…confusing question. In a fresh water cooled engine, there is only one thermostat and that is on the fresh water cooling side of the engine. There is no T-stat on the raw water side.
On a raw water cooled engine, there is also only one T-stat.
FYI, T-stats are not there to help cool the engine….they are there to help them warm up.

buster53 wrote:Source of the post
FYI, T-stats are not there to help cool the engine….they are there to help them warm up.

THAT should a 'sticky' on every maintenance forum!!

To maintain proper engine operating temp for efficiency.

Hi fellas, I guess didn’t explain my problem very well. I did the half system to make the boat usable in the salt chuck until I could do the full closed cooling system. I wish that I knew how to download the drawing that I have for the full Volvo Penta closed cooling system. According to the drawing, the thermostat housing has additional hose barbs for the four hoses that go to the top and bottom fittings on the exhaust manifolds. What I need is a way to connect the exhaust manifolds so that they circulate properly with the water pump. There are probably other ways to connect the exhaust manifolds, but I haven’t figured that out yet. If someone could explain how to copy the drawing into my post, that would be awesome.
Thanks

I think that I figured out the drawing part, it takes me a while, I’m just a dumb boilermaker after all!

As you can see, I’m looking for a thermoses housing, or something similar as to part #3 in the drawing. If anyone has any idea of how I can manage to duplicate tha housing would be much appreciated!
Thanks again fellas

Ah, that makes much more sense now!

Do you have a link to where you got that image?

Seeing as how the blocks are the same, I wonder if there'd be a way to adapt something like a Crusader thermostat housing to the Volvo motor?