What does MY outdrive seawater pump do?

[Reming870]

I have a 1978 Grady. 5.7 L MPI with Alpha One OD. Motor New install in 2009. Prior history unknown, no numbers available at this time as it is at Marina.

The closed cooling system uses the engine pump to circulate the antifreeze through the components and heat exchanger. There is another pump drawing water thru-hull through the seacock assembly that cools the heat exchanger. This pump is belt drive off the engine. The line off the outdrive pump is blocked off with a plug.

Is this normal? Does the outdrive pump still cool any components or gears in the outdrive?

 

[skydiveD30571]

Re: What does MY outdrive seawater pump do?

Apparently your old engine used a raw water pump in the outdrive, and your new engine has it belt-driven. No, there are no components in the drive that are cooled by the outdrive pump. Seems like they just blocked off the line since it isn't necessary anymore.

 

[Don S]

Re: What does MY outdrive seawater pump do?

The pump in the drive actually does cool the upper some. Merc recommends you cut the hose at the bellows and leave it open so the water from the pump passes through the upper housing which is out of the water and not cooled when on plane.

 

[Reming870]

Re: What does MY outdrive seawater pump do?

How does the water exit if you cut the hose?

I ended up purchasing the SEI replacement outdrive and am now curious how the water circuit will flow.
What hose do I need to cut and how will the water circuit flow properly to cool the upper housing?

I do not want to burn up gears in case that's why my original failed.

 

[Reming870]

Cooling Outdrive clarification

Cooling Outdrive clarification

I had a thread going on what my outdrive water circuit cools and now need to clarify something. I figured a new thread was best.

I now know that my outdrive water pump only cools internal circuits in the outdrive, or at least, that was the intention.

My Mercruiser has failed in the upper gear case Alpha One Gen II and I have ordered the SEI full upper and lower replacement for it.

How can I check to make sure the water pump in the outdrive is delivering water properly to the upper gear case circuit for cooling?

Does anyone have any detailed instructions for how the water circuit hose needs to be routed to get the water circulation proper through the outdrive?

Thanks.

 

[Don S]

Re: What does MY outdrive seawater pump do?

I merged your two threads together, since your last one misses out on a lot of very important information.

There is a diagram on it, I just have to find it.

Found it.

View attachment Alpha cooling hose.pdf

 

[Reming870]

Re: What does MY outdrive seawater pump do?

It is not clear to me (step 5) how water will flow through the outdrive and discharge out. If you remove the hose where is the water flowing?

 

[Don S]

Re: What does MY outdrive seawater pump do?

The pump is on top of the lower unit. It pumps water up through passages in the upper gear housing and out that hose. It just pumps out into the air. The passages in the upper is what is getting cooled.