3.7 / alpha 1 winterizing questions

[johnzonh]

well my season was kinda short but I got my engine going..ran like a charm. I am going to pull the outdrive over the winter so I can paint it, repair an oil leak. The gears have been great and otherwise have had absolutely no issues.

regarding the engine with the closed cooling... on the raw water side (this being my first experience with a heat exchanger) do you guys pull the exchanger end plugs off and leave them open ? I haven't seen too many posts on this..just wondering... I am going to run some 50/50 rv antifreeze through the raw water system before I pull the outdrive...just so I am covered. I need to buy new exchanger gaskets next spring (the old ones with the red RTV look kinda dumb..but it worked)

john

 

[HT32BSX115]

well my season was kinda short but I got my engine going..ran like a charm. I am going to pull the outdrive over the winter so I can paint it, repair an oil leak. The gears have been great and otherwise have had absolutely no issues.

regarding the engine with the closed cooling... on the raw water side (this being my first experience with a heat exchanger) do you guys pull the exchanger end plugs off and leave them open ? I haven't seen too many posts on this..just wondering... I am going to run some 50/50 rv antifreeze through the raw water system before I pull the outdrive...just so I am covered. I need to buy new exchanger gaskets next spring (the old ones with the red RTV look kinda dumb..but it worked)

john

Howdy,

I installed full closed cooling on my 7.4L engine several years ago. All you really need to do is drain any pooled water in hoses that might hold water and drain the heat exchanger.

Alternatively, you can do like you say and run some 50/50 in via the water pickup in the drive BUT.....understand that there's going to be a certain amount of pure water pooled in the heat exchanger, hoses, etc. so if you start with 50/50, it might be less than 50/50 when you're done unless you run enough to purge it.......

ALSO, you need to prime the raw water pump by applying positive pressure from the receptacle with the AF "mix" to the muffs (or you risk running the impeller "dry") .
I have used a 5gallon container sitting on the swim-step. I started a siphon from the container to the muffs before starting the engine. (I have a Bravo)

With an Alpha, you might be able to use a container that allows to the liquid level to submerge the raw water pump but it'll take a big "tub" to put the drive into.

I don't do any of the above anymore......

This is ALL a whole LOTTA work when you can just drain the heat exchanger and any hoses that might pool water!

If the intake/ex manifold is also part of the closed cooling system on your 470, All you really need to do is drain the exchanger and associated hoses.

Go to Home depot and get some Sched 40/80 fittings and a couple of plastic ball valves, put them where the lowest point of the hoses and you can drain everything that needs to be drained!

ymmv......


Rick

 

[johnzonh]

hmmm ok sounds good. yeah I have seen a few youtube posts with people doing the swim step thing.. needless to say I had a great short season (engine stayed no higher than 130 degrees with a new thermostat ) and I didn't burn much, if any oil.

I didn't service the drive this year other than the impeller... so to satisfy my curious mind I am going to pull it, paint it, replace seals etc and check shaft clearances just to make sure all is well in bearing and seal land. Shift cable is getting stiff and the bellows had a hole so I am going to replace both.

 

[mr 88]

There are two plugs in the rear of the heat exchanger,obviously on the bottom. One is anti freeze and the other is freshwater.I believe the one closest to the stern is the freshwater plug,unscrew that and your good to go. If anti-freeze comes out then you unscrewed the wrong plug.There is really not a level hose in the freshwater system so I would not worry about that as it will all drain out one end or the other.If the shift cable housing is good you may be better off just replacing the cable and using the old housing.The bronze nut that screws into the bell housing can be a real pain to remove,I know from recent experience and in hindsight I wished I had just replaced the cable and left the housing intact.Running anti freeze through the freshwater system is a waste of money as none of it gets close to the block,heat exchanger and maybe Voltage regulator depending on your setup and thats it,never enters the block.

 

[stonyloam]

Do not fool around with antifreeze. 88 is right, all you need to do check that the antifreeze in the reservoir is about 50/50 and pull the aft plug on the underside of the exchanger and let it drain. That is it. I do mine right on the ramp when I pull the boat for the winter, takes about 5 min.

 

[Eric 3.7LX Alpha 1]

Easy.... here are 4 pages from the manual covering it all Page 1:

 

[Eric 3.7LX Alpha 1]

Easy.... here are 4 pages from the manual covering it all Page 2:

 

[Eric 3.7LX Alpha 1]

Easy.... here are 4 pages from the manual covering it all Page 3:

 

[Eric 3.7LX Alpha 1]

And here is the last page. If your worried about freeze damage, check the coolant strength in the engine. drain the aft end plug at the bottom of the exchanger. If you open the drain in front you will release antifreeze, and if you have a drain on the power steering cooler open it as well. I don't remove the end caps just the aft drain and have never had any issues here in New England.

The other pages I uploaded cover the rest of the winterizing process besides freeze protection.

 

[1977 SILVERLINE]

Depends how cold it gets where you store it. It has already froze where my boat is and I'm not ready to put it away for the winter yet. If it doesn't get below 20 I just lower the drive and drain the heat exchanger. When I winterized it I use some muffs a piece of garden hose and a funnel. I buy one gallon of rv antifreeze have someone start the engine and pour the whole gallon through. Then I open the drain on the exchanger and it is winterized.

 

[stonyloam]

You are taking a big chance if you do not drain the exchanger BEFORE you add the antifreeze and once drained the antifreeze is unnecessary anyway. Also you are taking a chance on burning out the exhaust shutters and impeller if you are not pumping enough antifreeze through the exhaust to cool them.

 

[johnzonh]

ok good info guys I managed to get out one more time with the kids a few days back. This weekend I will start the winter layup. Thanks for the reprints..(first thing I got was the #8 and #6 manuals..I wasn't messing around) I must say it has been a nice engine...and has quite a bit of umph. I know that there are plenty of naysayers out there with it.....especially concerning the over zealous fuel pump and the crank driven alternator. I will post again in time with other questions I am sure. anyone know of a good '3.7 lovers' website?

 

[stonyloam]

Breezeworks. http://www.breezeworks.net

 

[nola mike]

anyone know of a good '3.7 lovers' website?

This one (well, there are 3 or 4 of us kicking around anyway)...