How much antifreeze??

[brianwhart]

I've got a 97 4.3 mercruiser. I'm going to use some of this RV/Boat Antifreeze to winterize it. Anybody know how many gallons will it take?

 

[Boatin Bob]

Re: How much antifreeze??

You know the RV/Boat antifreeze (pink stuff) isn't really for winterizing boat engines, it's for the water systems. If you are going to let antifreeze sit in your engine over the winter then you should use the stuff that has the anti corrosive properties in it to help protect your engine. I would expect 2 gals (of mixed) should fill your block and hoses.

 

[brianwhart]

Re: How much antifreeze??

Is that the green stuff? How do you get it back out of engine without causing an environmental disaster? Or do they make an environmentally friendly antifreeze with these anti corrosive properties?

 

[cobra 3.0]

Re: How much antifreeze??

If rust were a problem, then water that sits there the other 6 months of the year, would be an issue too! Unless you are using your boat in salt water, I don't see the problem.

 

[Mark Bennett]

Re: How much antifreeze??

I have a 93 4.3LX gen II and it takes at least 3 gallons of 70% mix to fill it. I like to mix it a little strong so that if it hits any pockets of water in any of the hoses or pumps they'll be enough concentration after it mixes. I usually pull the plugs and hoses and let them drain into a funnel and hose that I have snaked through the drain plug.

 

[andrewgroup]

Re: How much antifreeze??

Every boat dealer in the Indianapolis area and my self do a dryblock winterize. I personally run a 60/40 mix of Automotive Antifreeze through the engine when I'm all done with the winterizing stuff like oil and filter changes, etc. I bring the engine up to operating temp on the water hose and the muffs. I think slide my 4' plastic baby wading pool under the outdrive / drainplug, I pour in my 4 gallons of antifreeze mix. I have a portable sump pump that I connect to the muffs using a 4' hose and start the pump, then I run the motor for about 5 to 10 minutes making sure the temp get's hot enough to assure me the thermostat opened...(About 160) after running at that temp for a bit I fog the engine to a stop.<br /><br />Shut it all down, open the drain plugs, drop the lower water hose, remove each spark plug and spray a bit of fogging oil directly in each cylinder. Install a new sparkplug. soak the spark arrestor in Gasoline, blow it clean using compressed air.<br /><br />clean and inspect electrical connectors, spray with CRC electrical connector spray, Lower the outdrive to relax the bellows, (of course I also changed the outdrive gear lube) remove battery, that's a wrap....(Add Stabil for full tank on last trip out, fill tank on return trip home)<br /><br />Professional boat firms use a device from yardarm that is the professional version of my swimming pool. http://www.yardarm.com/docs/winterizetank.htm

 

[MrBill]

Re: How much antifreeze??

Boatin Bob gives the right advice...winterize with the appropriate antifreeze for engines, it contains the proper lubricants, anti-corrosion properties and low temp protection. The RV stuff is for PVC and other plumbing...and not meant to protect to really low temps after mixing with water 50-60%. A gallon of the right stuff is only 6 bucks...

 

[Ralph 123]

Re: How much antifreeze??

They make several grades of "safe" antifreeze. The pink stuff, the cheapest, has little or no rust inhibitors depending on the maker. Then they make purple and blue both of whic do contain rust inhibitors. The purple goes to -60 or so and the blue -100 - check westmarine or boatus and you'll see what I mean.

 

[Boatin Bob]

Re: How much antifreeze??

Cobra 3.0 rust is a problem, if your manifolds, water jackets, passages, risers are going to sit empty all winter then there is going to be rust. When I winterize my engines I drain them into the bilge and I pump,sponge and wipe up all the water. Then I fill the blocks,hoses with green antifreeze for 2 reasons, any water left in there will mix with the antifreeze plus I get corrosion protection over the winter. In the spring I drain them again into the bilge and I capture all the antifreeze and have actually reused it the next year or dispose of it at the proper facility. A lot of people winterize differently, but mine has worked for me here in Canada for several years with no problems.