Winterizing a Merc A1-G1 Block Question Antifreeze

[1985 Century Mustang]

I'll be winterizing my boat in a few days, and focusing on the block right now.
Question, can I use regular antifreeze in the block, or do I need marine antifreeze?. After all it is a Chevy block. Your thoughts.

 

[Bondo]

Ayuh,....... I've been winterizing motors for decades,.... Drained, 'n dry,....

 

[1985 Century Mustang]

Ayuh,....... I've been winterizing motors for decades,.... Drained, 'n dry,....

So your draining the block dry and your not using antifreeze?
If so do you run the motor briefly without water, please elaborate. Can you post exactly how you do it? Thanks

 

[Candy Gramformongo]

I bought a '70's era Mercruiser 120 this year and just winterized it for the first time.

My understanding is that you can use automotive antifreeze. It just so happened that I did a drain and refill on three cars this year, and saved the old antifreeze. I have a lifetime's supply of boat winterizing antifreeze.

Also, at least for the 120, antifreeze is optional, but "recommended." Supposedly just the drain is adequate protection, but under the theory that you can never be too safe, you can also put in antifreeze.

 

[Bondo]

So your draining the block dry and your not using antifreeze?
If so do you run the motor briefly without water, please elaborate. Can you post exactly how you do it? Thanks

No,...... Pull the drain plugs, probe the holes with a pick to knock any crud outa the way, then when drained, put the drain plugs back in,....
Also, remove the bottom of the big hose, to drain any water hidden in the circulating water pump,....

 

[Scott Danforth]

we have a sticky.

Winterizing Inboard and I/O

Winterizing your engine and drive. Winterizing your boats engine and drive is a lot of work. Not doing it or doing it improperly WILL be very expensive to fix , and that is also a lot of work. Plan on giving yourself the full day to winterize your boat, and don't wait till the last minute to do...

forums.iboats.com

 

[Lou C]

If you're going to use AF, the way to do it is to use non-toxic Propylene Glycol with corrosion inhibitors. If you use toxic Ethylene Glycol that's going to be spilling all over your driveway when you start up in spring.

 

[Chris1956]

Gee, Lou, In the spring I used to drain the antifreeze back into it's original containers and save if for next season. I saw no reason to dispose of it each year.

 

[1985 Century Mustang]

@Bondo So if I remove all the water with the drain plugs and lower hose etc. This should be suffice. Could it hurt to add some antifreeze also?

 

[Bondo]

@Bondo So if I remove all the water with the drain plugs and lower hose etc. This should be suffice. Could it hurt to add some antifreeze also?

Ayuh,...... If yer into throwin' money away, go for it,.....

 

[Lou C]

Gee, Lou, In the spring I used to drain the antifreeze back into it's original containers and save if for next season. I saw no reason to dispose of it each year.

You can though it might be mixed in with some dingy bilge water and motor oil drips lol.
Might try it next spring. clean bilge out, drain then put plug in drain af, then remove plug and put AF back in containers.

 

[1985 Century Mustang]

Ayuh,...... If yer into throwin' money away, go for it,.....

I have a gallon of new AF from last year unused. I'll throw it in.

 

[DeepCMark58A]

I prefer to pickle my motor, automotive antifreeze also has corrosion inhibitors.

 

[Lou C]

So does West Marine (-100 burst protection, -50 freeze protection) and Sierra PG automotive antifreeze which you can mix up to whatever strength you need, I mix mine to -30*F.
both non-toxic & both have corrosion inhibitors.
BTW I have done this each winter for 20 years, boat is used 100% in salt water, sits on a salt water mooring all season May to Nov. So far the block and intake manifold have not rusted through. I replaced the cyl heads but that was mostly because of overheat damage. Now you freshwater guys don't have to worry about this but here in the salt pond, the engine and exhaust gets filled with PG antifreeze and the trailer gets sprayed with Corrosion X on all the fasteners, springs, etc. I think it works, it has for me.
So do what you think is needed in your environment. I know what works in mine....

 

[Chris1956]

Lou, 20 years is a long time for risers and exhaust manifolds to last in salt water. You might slide the rubber sleeves off the risers and have a look at the risers. That is where they tend to rust away first.

 

[Lou C]

Lou, 20 years is a long time for risers and exhaust manifolds to last in salt water. You might slide the rubber sleeves off the risers and have a look at the risers. That is where they tend to rust away first.

Ahh of course you’re right, that’s the one thing that I have replaced repeatedly in salt water
Installed set # 1 in 2004
Set # 2 in 2011
Set # 3 in 2017
I monitor the temps with an IR temp gun & just bought an endoscope camera. When I winterized it I removed the rubber hoses and scoped both elbows. You can actually see down into the joint between the manifold & elbow. They still look good not leaking inside. Installed this set in 2017 but used for 5 seasons in salt. Prob will replace by end of season 7.

 

[Chris1956]

Lou, You probably know this, but for those lurkers that may not, aftermarket manifolds and risers are fine to use, but make sure the gasket between them is a good one. I had the green paper gasket that came with the Osco-brand products fail one day and the engine hydro locked, luckily with fresh water. The boat was being readied for the season and was on it's trailer. The Manifolds and risers were a couple of years old and had been working fine.

I pulled the spark plugs and blew out the water, changed the oil, trued up the mating surfaces between manifold and riser and installed the silver MerCruiser gaskets and never had an issue again.

It would have been real bad if the engine hydro locked while it was moored in saltwater. It could easily have ruined the engine.

 

[Lou C]

Agreed, what you can do, is use aftermarket manifolds & elbows, but use an OEM gasket. I used the Barr kit on the last job because I had to finally convert from the OMC batwings on the V6 to the later 2 piece style, I used the Barr gaskets coated with Permatex Aviation, and no leaks. The Barr gaskets are very similar to the Merc silver gaskets.
If it didn't come with good gaskets, I would have used Volvo OEM gaskets, and the sealer they advise in their instructions.
The other thing is before installing the elbows, make sure that the bolts will thread all the way in, or else you might not get full or even torque on them, I'd use a thread chaser for that.
When the next change is due, I might try to adapt the Mercruiser dry joint style to my OMC engine, I could use the Barr kit for this, the thing is while the angles of the elbow exit are the same (7*) that doesn't mean that everything will line up. Might talk to a local shop and see if I can borrow a used set, just to see. That's one of Merc's better ideas for sure.

If you do a lot of your own work, that borescope camera is really useful, a real time saver.

A real useful tool….

I got one of those endoscope camera and esp for I/Os used in salt water they are real time savers. Today I used it to scope the water intakes of the Cobra drive where I have had an issue with barnacles growing there in the past. Found a little growth easily removed with a coat hanger wire. I’m...

forums.iboats.com

I used it to scope the manifolds and also the water passages in the outdrive, had some barnacles growing in there....

End of season maintenance checks…

Since I did my top end overhaul back in 2017 I’ve been doing oil analyses and compression tests just to see if there are problems developing. Oil analyses have improved over time and this years compression test was the same as last years, 160-165 in all 6 cyls. I think it’s a good habit because...

forums.iboats.com

here there are a few pix of the inside of the elbows....one was totally clean the other had a bit of rust but I think that is from condensation, the exhaust on this engine runs really cool at idle and that side is the cooler of the 2. Like 85-95* at idle, barely warm.

 

[1985 Century Mustang]

Ok so I went out to drain the block today via the drain plugs on the exhaust manifold (there are 2), one brass plug i had opened (towards the elbow riser area) and it had drained out a substantial amount of water. But the other drain plug with the blue plastic peacock valve seemed to be blocked off somehow. I tried removing the peacock valve and also the fitting but it was solid inside there as no water could come out from it under the exhaust manifold itself. Further, I tried using a small piece of pry tool to open it up because I thought it may of been blocked from debris etc, , but to no avail. I'm wondering if that plastic peacock fitting area and the actual inside of the exhaust manifold was originally blocked off by the manufacturer. Again the first valve I opened had drained out a lot of water. I'm wondering if this is ok. Your thoughts.

 

[Lou C]

Which engine do you have? In-line 4, V6 or V8?
The block drain on the 4 is on the side under the manifold
On the V engines there is one drain on both sides of the block, in front of the starter on the starboard side & in front of the oil filter mount on the port side. For the manifolds it can be on the underside or on the end it all depends on the brand of manifold. Don’t forget in addition to that you have to disconnect the bottom end of the big hose in front between the front circulating pump & the thermostat housing that holds a fair amount of water….probe the holes with a pick or small screwdriver…