Draining SB8 raw water system on a 1978 Hunter 27

[John5961]

It's starting to get cold here at night (low 30 to mid 20) so I thought I would drain my SB8 water system and my fresh water system. The fresh water tank and sully lines are no big deal, but I'm not sure about the SB8 diesel cooling system. I've had the impeller out (to inspect it) so I am somewhat familiar with the engine I found some information that stated you should close the seacock, remove the inlet and out let hoses from the water pump to let them drain and then do something else (Undecipherable) to drain the rest of the engine. Any idea what they were talking about? I could use some advice. ThanksJohn

 

[Jerry]

First question...why?

If you are winterizing your SB8, just close the seacock, remove the hose from the intake side of the pump, attach another hose section to the pump and stick it into a gallon container of -50 or -60 antifreeze and run the engine 'til the antifreeze color runs out the exhaust. Then, re-attach the intake hose to the pump. This is a good time to examine all of the hose clamps, too. In my experience that has taken 1.5 gallons of antifreeze. This can be done in the water or on the hard. If done wet, don't start the engine again 'til spring launch AFTER REOPENING THE SEACOCK! (voice of experience)Jerry

 

[John5961]

Thanks

thanks for the advice. Do you use the non toxic RV type antifreeze?

 

[Jerry]

Use non-toxic...

...for winterizing. As long as the antifreeze has the anti corrosion content for the engine, you should be good. You should be able to use the -50 degree AF in your location. Suggestion; once the seacock is closed and the boat hauled, you have a great opportunity to clean and re-lubricate the seacock mechanism and attach the wooden plug we should all have with the valve.Jerry

 

[Dan Bryant]

Engine Anti-Freeze

While the non-toxic (pink) anti-freeze is about the only option for the drinking water system, my experience is that you should tend towards the engine anti-freeze (green) for both the engine and the head. The pink stuff tends to harden rubber, while the green does not (and even acts as a lubricant, in the case of the head). I ended up having to replace the rubber parts in my head after using the pink stuff. I don't know if it would have a similar effect on rubber impellars, but there is no reason to risk it.