Freezing Mercruiser v8

cruisa

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Hi guys, Thinking of buying a boat with a 2005 merc v8 5.0L 220hp mpi with alpha 1 gen 1. Engine only has 36hrs and outdrive is 1988 origonal. This will be the first engine i have that is raw water cooled only and my concern is when i come back from sea, salt water, the engine is flushed by the river at my mooring, fresh water, is there a danger of freezing water in the block as the boat is in commission thoughout the winter. If so how can this be avoided?
Any help much appreciated :eek:
 

mkast

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Re: Freezing Mercruiser v8

Fresh water cooling system, Does the river freeze? The sterndrive.
 

cruisa

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Re: Freezing Mercruiser v8

No, the river doesnt freeze but the air temp can get as low as -10c
 

cruisa

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Re: Freezing Mercruiser v8

So is the solution to retrofit a heat exchanger and closed loop with glycol? There is a drain lever on the front of the engine to drain the block water into the bilge but is this enough? The boat is normally in commission through the winter. Cheers
 

rbh

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Re: Freezing Mercruiser v8

if the temp can get down to minus 10 c you are probably on the west coast, van isle?
if you have shore power look to see if they make a circulating block heater (like they use on cars ) that you can cut into the system?
rob
 

bruceb58

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Re: Freezing Mercruiser v8

So is the solution to retrofit a heat exchanger and closed loop with glycol? There is a drain lever on the front of the engine to drain the block water into the bilge but is this enough? The boat is normally in commission through the winter. Cheers

Even with a heat exchanger, you can have freezing problems with the water on the raw side of the heat exchanger.

What do other people use at your marina?
 

cruisa

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Re: Freezing Mercruiser v8

Thanks Rob, no im on the south coast.......... of England :) I don't have shore power available. Will the block drain work or do you think it will leave too much water in the engine. Have had outboards on the mooring for ten winters without a problem but i assume they drain automatically. Glenn
 

rbh

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Re: Freezing Mercruiser v8

we generally plug our cars and trucks in when the temp goes down below the 10c-20c mark. we have a choice between a circulating style heater that moves the glycol/anti freeze around or the more common block heater, you pull out one of the middle frost plugs on the side of the block and tap the plug with the heating element in its place.
they are usually 750 to 1500 watts to run.
if you use a circulating style hopefully it would pull the water in the leg, heat it and the block and leg on its way out?
or just pull it out of the water and drain every thing.
rob
 

cruisa

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Re: Freezing Mercruiser v8

-10 to -20? thats much lower than what we get here. -10c is the worst case, maybe once or twice per winter. sometimes we have -3 for a few days but average temps are between +3 to +6. maybe im worring for nothing? The heater sounds good but I have no power available. Glenn
 

FreeBeeTony

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Re: Freezing Mercruiser v8

Is it fresh or salt water?

EDIT........I see you are in a river after the sea.
 

gadget73

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Re: Freezing Mercruiser v8

I'd go with a fresh water system that includes the manifolds, and get in the habit of draining the raw water side of things after each use. A block heater wouldn't be a bad idea either, it should help keep the engine compartment warm enough to keep any residual water in the lines from freezing up. You're still risking having water freeze in the area around the transom assembly and where the water hose connects from the drive itself into the transom assembly, as thats above the water line in some parts. Not much to be done for that, but a hose is a whole lot cheaper to deal with than a cracked engine block.
 

Bondo

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Re: Freezing Mercruiser v8

Will the block drain work or do you think it will leave too much water in the engine.

Ayuh,... That'll Work,... But you might have to add drains Merc didn't include...
And,...
They should be so that they can be rodded out with a screw or nail,...
Just so they don't get Plugged...
 

cruisa

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Re: Freezing Mercruiser v8

Thanks Bond-o. Think i will go with that. best places to add drains on a v8 block? Thanks all for your help. Glenn
 
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