Valve on the Bottom Of Manifolds Purpose?

[jeffk]

I replaced the manifolds today, and noticed the ball inside this valve was stuck. I freed it up and cleaned it. Put it back together.
Does this cause overheating?
What is this valve called?
What is its function?

It is 8, 9, 10, and 11 on the attached link.

http://www.mercruiserparts.com/Show...681&bnbr=200&bdesc=Exhaust+Manifold+and+Elbow

 

[Bt Doctur]

It might if it was preventing the water flow thru the manifold

 

[Happy Hour IV]

Just as it says in the diagram. drain

 

[jeffk]

Its not a drain, it recirculates. And the ball was stuck in the up position.

 

[Jimmy Buoy]

I have the same setup on my 8.1's. It is a one way valve that allows the air actuated drain system to operate. For the system to drain water out, it must get air from a higher point. The system gets that air from the exhaust cooling water passage that is open to the air in the exhaust hose. Basic plumbing ie vent lines.

It is a floating ball for a reason. When the engine is running water is forced from the raw water pump throughout the system. In my case, through a transmission cooler, oil cooler, fuel cooler, engine cooler, then finally exhaust manifolds and out. If that little ball was missing, most of the water would simply go up that hose, into the exhaust manifold and out. That would make all the other coolers mentioned starved of cooling water - very bad things would happen! The ball floats upward, blocking flow into the exhaust manifold from that particular hose.

If it's blocked shut, it just means your system won't drain as quickly or completely as it should.

 

[jeffk]

Thanks for the explaination Jimmy

 

[stwischu]

I have the same setup on my 8.1's. It is a one way valve that allows the air actuated drain system to operate. For the system to drain water out, it must get air from a higher point. The system gets that air from the exhaust cooling water passage that is open to the air in the exhaust hose. Basic plumbing ie vent lines.

It is a floating ball for a reason. When the engine is running water is forced from the raw water pump throughout the system. In my case, through a transmission cooler, oil cooler, fuel cooler, engine cooler, then finally exhaust manifolds and out. If that little ball was missing, most of the water would simply go up that hose, into the exhaust manifold and out. That would make all the other coolers mentioned starved of cooling water - very bad things would happen! The ball floats upward, blocking flow into the exhaust manifold from that particular hose.

If it's blocked shut, it just means your system won't drain as quickly or completely as it should.

Yes I know, Im responding to an 8 year old post. But this helped me alot. Changing the elbows, risers, manifolds on my boat right now. I had that same stuck elbow fitting on the manifold bottom. What baffled me was the replacement manifolds (Sierra) came with a different style elbow with the blue drain valve, instead of the ball valve and hose fitting. I managed to remove the old valve from the manifold but didn't know what to do with it, til reading your post. Cleaned it, poked at it and the ball came loose. Magic! Thanks.

 

[Jimmy Buoy]

Glad to see that it helped!