clarification on closed cooling system please

[rick3452]

5.0 M/C 0m012817 / Bravo 3

Does a "half system" mean that there is no " coolant/antifreeze " going to the risers at all?

If that is correct than any loss of coolant from the overfill bottle, or heat exchange, could not be leaking from a riser gasket...

I'm pulling the risers today 1 yr old, and replaceing the gaskets with OEM (the same ones I used (oem) last year).
Thanks much!
Rick

 

[achris]

Re: clarification on closed cooling system please

Clarification of terminology.

Elbow - section at the top of the exhaust system where exhaust gas from the engine and water from the cooling system are mixed before exiting the boat via either the y-pipe and stern drive unit or thru-hull exhaust tips.

Riser - extension used between manifold and elbow to raise the height of the elbow. Usually available in 3" and 6".

On to your question.

Half system means only the engine block and heads are fresh water cooled.
Full system includes the exhaust manifolds, but NOT the elbows and risers.

In a half system there would be no loss of coolant through a failed elbow/riser to manifold gasket.

HTH,

Chris........

 

[rick3452]

Re: clarification on closed cooling system please

Thanks Chris.... I thought the "riser" bolted directly to the manifold. I guess thats what you're calling the "elbow" I have no other spacers between the manifold & elbow and no other hoses going to the manifold set up, only the blue drain on the bottom.
Thanks again......Rick

 

[Don S]

Re: clarification on closed cooling system please

Here are a couple of pictures from the service manual that may help you. If you don't have antifreeze in your manifolds, you have a half system. The elbows on either are always raw water cooled. That is how the raw water exits the system.

 

[rick3452]

Re: clarification on closed cooling system please

Don, Thanks so much for the pictures. Little by little I'm learning thanks to all of you.........
Rick