Filling block with antifreeze

[sgs01]

Is it possible to use the raw water pumps on my engines to suck antifreeze into the block instead of draining the block's? Draining the block's is a massive pain (literally) and if there is a way to avoid that it would be much better.

Thanks!

 

[Strecker25]

Are your engines fresh water cooled (blocks filled with AF) or raw water?

 

[sgs01]

They are raw water cooled

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[Lazy Daze]

There's many, many posts on this subject and with a little searching you can find lot's of answers.

However, the only GUARANTEED safe way to do it (other than using probably 20 gallons of AF per engine) is to drain the engines. But you also will need to remove the t-stat. If you do that (drain, remove t-stat) then you can suck the AF in through your raw water pump. However, it's often just as easy - if not easier - to simply add the AF back in through your t-stat hoses.

Yes, working on boat engines can be a very tight squeeze at times, often requiring things done "by feel" only!

 

[sgs01]

Sigh...sounds like a closed cooling conversion is in order

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[Strecker25]

I think most people here will agree (I'm really just echoing what I've read on this board from smarter people than me) that pumping the AF through without draining is really a crap shoot. If you're going to do it with the engine running you will almost certainly have to remove the t-stat housing and then remove the thermostat to ensure the AF gets through the block. Even with that method you would have to run an awful lot of AF through the engine to be sure the pockets of water in the block is pushed out and displaced with AF completely. The drain plugs can be a pain, but it really is the correct way.

 

[sgs01]

That's what I was afraid of. What I think I'm going to do is to get the marina to go ahead and winterize it until I convert to FWC later.

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[Westie]

Its a lot easier to remove the drain plugs than to remove an engine to replace it after the block has cracked.

 

[sgs01]

That's what I thought. A bilge heater really isn't an option either because my boat doesn't have a genset so I would be totally at the mercy of shore power at the Marina.

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[JVM225]

When I still had raw water cooled blocks, I would drain them, pull the hose of the T-stst housing, pour the AF in to the hose until they were full, and that was it.
Never had a problem doing it that way.
Don't forget to drain the exhaust too.