Thermostat question

E

estame6

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27400
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Hi all, That time of the year again and I have a quick question.

1988 Sea Ray 30' Weekender with 2x 260 hp 5.7 liter Mercruisers Straight Shaft. When draining the blocks using the drain cocks at the lower sides of the engine block can anyone tell me if there is any liquid left in the engine other than maybe a small amount beside the actual drain cocks due to the angle of the engine. I understand there will be some in the risers and mufflers but more concerned with the actual block.

Many thanks....
 
In a 29 yr old RWC block there are bound to be lots of rust flakes and other debris around those drain areas even when use is in Great Lakes FW. So all water may not drain even if a wire is inserted in the drain to move debris around. I'd suggest running many gallons of at least-60* non-tox A/F through the system after your draining and closing those valves may protect the block and other parts ( muffler, etc.?) better. Some, definitely not all, non-tox A/F has corrosion inhibitors as well I believe.

I don't see a "thermostat question" in your post , but removing the T-stat temporarily to run the A/F through will prevent having to wait for it to open before adding the A/F so it circulates properly.

Fake-A-Lake is one means of supplying the A/F, or just disconnect the RW supply hose at the seacock or sea strainer and insert into a full 5 gal bucket of non-tox.
 
very little will be left from the engine angle ,simply remove the large hose from the T stat housing and pour the A/F in.Remember to drain to drain the raw water pumps and lines. domt forget the trans coolers
 
I drain all plugs (I have 5 per engine); reinstall all plugs; then remove, one by one, each hose attached to the thermostat housing (I have 4 per engine) and pour antifreeze into each, slowly, until it overflows, reattaching after each overflow. Whatever water is left in the engine is diluted enough to effect full freeze protection.
 
Thanks all for the good info.

I have always drained the engine via the plugs, removed the thermostat, drained the muffler and sucked out the water from the raw water strainer. I don't worry about the exhaust manifold and risers as the little water I get out of those is probably 1/2 cup and removing the four plugs really isn't worth the the effort. I have a three way valve between the raw water intake shut off and the strainer which I attach a 6 gallon bucket full of Red Pop which I suck through the engines. I take a sample of A/F as it shoots out which I take a reading with my neighbors "Ade Advanced Optics Anti-F Fahrenheit ATC Glycol Antifreeze Refractometer" and measures pretty darn close to what goes in. I've been doing this for over 9 years now with out a problem but looking for some short cuts.

The reason for this post was to try figure out how much water is left in the block after opening the two plugs on each engine. I am totally fed up removing the thermostat each year and was hoping there was little or no water left behind and I didn't need to remove them and understand without the thermostat opening very little A/F will get to those areas and would there be any water that wouldn't drain out? The other thing I tried this year is after loosening the plugs and draining out the water is to leave them loose, run the A/F through the engines and allow the A/F to completely run out then tighten the plugs. Is there a reason to keep the A/F in the block?

Dave
 
"Is there a reason to keep the A/F in the block?"

IMHO---YES. Not only reverts freezing, It prevents corrosion.
 
quote:
Originally posted by alien1952

very little will be left from the engine angle ,simply remove the large hose from the T stat housing and pour the A/F in.Remember to drain to drain the raw water pumps and lines. domt forget the trans coolers

Click to expand...


That’s all you need. Also, poke in the drain holes on the sides of the block with a nail or something to push any rust flakes that may be preventing everything from draining out.
 
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