Winter use of Mercruiser

[Mechmagcn]

We live on a river in south AR and use a boat as daily transportation. Currently using a Jon boat with an outboard, but am working on a larger pilothouse boat with a Mercruiser Alpha I and 3.0 liter. This boat uses raw water cooling.
My question is this: We occasionally have sub-freezing temps here at night, seldom getting into single digits, but last year we had temps close to zero. In temps such as these will I have to be concerned about the manifolds and block freezing? Other than putting a heat source in the engine compartment, what other options are there? I have seen automatic block drains, but have read that they are problematic and clog easily.

 

[Bondo]

My question is this: We occasionally have sub-freezing temps here at night, seldom getting into single digits, but last year we had temps close to zero. In temps such as these will I have to be concerned about the manifolds and block freezing? Other than putting a heat source in the engine compartment, what other options are there? I have seen automatic block drains, but have read that they are problematic and clog easily.

Ayuh,...... Welcome Aboard,....... In such a situation, if there's a Chance of freezin' temps,....
Put the drive down, 'n drain the motor,.....
It's only 2 or 3 pipe plugs, 'n pullin' the big hose of the circulatin' pump,.....

Easy peasy,.....

Remote or auto-drains don't account for silt, sand, nor rust,......
Always poke out the drain plug hole to be S u r e the water can easily drain,.....

 

[Mechmagcn]

Would the addition of a heat exchanger make a difference or would it have to be winterized also? Not too familiar with the inboards, is a heat exchanger even possible on this system?

 

[Scott Danforth]

yes, a full system would help as you would only have to deal with the exhaust elbow then.

however on a used motor, you run the risk of fouling the heat exchanger, and if you boat in brine or salt, you cant put a HX on a used motor.

 

[QBhoy]

Just pull the drains as said above after each use. Put them back in and as soon as you turn the key again it’s un winterised. Then repeat each time. Takes 2 mins.

 

[Mechmagcn]

As I said in the original post, this boat will be for daily use and will stay in the water year round. I'm glad we don't have that many days that the temps stay below freezing, draining the block and manifold twice a day could get old real quick.

 

[harringtondav]

As I said in the original post, this boat will be for daily use and will stay in the water year round. I'm glad we don't have that many days that the temps stay below freezing.

It's risk vs. prudence. But if you run the boat twice daily the engine temp of 140-160 will keep it's heat for quite some time. Especially when moored in (fresh) water which maintains 32 degrees. If you tie it up at full temp and start it back up w/in 6-8 hrs. you'll probably be OK. If it gets into the single digits you may have to take a long lunch to warm it back up early. This includes getting up early at your home slip to warm it up on very cold nights.

You might consider laying a heavy blanket over the engine between runs. But be sure to remove it before restarting. If you have 120V close to your home slip, an IR heater plus the blanket may keep you in bed longer.

Risk vs. effort. No guarantees.

 

[achris]

.... If you have 120V close to your home slip, an IR heater plus the blanket may keep you in bed longer.

Used to be a common practice years ago. But plenty of engine blocks got replaced after the power goes down for a day or 2....

Not sure what the answer is here. I think I'd be putting 1/4 turn valves on the drains and just cracking them open and sticking a piece of wire up after each run. Super quick, and nothing sticking in the back of the mind....

Chris.....

 

[Mechmagcn]

Thanks for the replies. Sort of wondering about my choice to go with the I/O now. Just tired of fooling with two 30 year old outboards and the major sticker shock when I think of replacing them.
I've got some other questions, but I'll save them for another post.

 

[zellerj]

I put ball valves on my engine drains. Now I do not need wrenches to drain the blocks. The opening in the ball valve is still 1.4 inch, so I can poke them with a wire to make sure all of the water drains out with a good strong flow. You can suck the water out of the bilge with a shop vac. .Leave the ball valves open so that water does not get trapped in the valve. If you only need to do this before cold snaps it would not be too much bother.

 

[TyeeMan]

Sooo, could a guy install a block heater? I mean it's a common item up here in the north land in vehicles. Or would that not be marine "legal"? All you do is remove a core plug, install the block heater and away you go.

I've always wondered if that would be a safe thing to do. Come to think about it, for all the I/O's and inboards that sit in slips in cooler/cold water until they get taken out for the winter you would think that could be a viable option.

Perhaps I'm missing something?

 

[Mechmagcn]

Sooo, could a guy install a block heater?

I'm not sure, but I don't think the block stays completely full of water when not running and the heater element must stay submerged.
I would think more along the lines of an oil pan heater, that might keep the block above freezing.

 

[Mechmagcn]

Oh yeah, there's power at both our dock and the rented marina slip we park in daily. My wife is a "princess" that doesn't like the cold, there's an electric heater in our current boat on a timer, so it's warm for the trip out and back home.

 

[kenny nunez]

The oil pan heaters also keep the engine warm year round which prevents condensation from forming rust. Also the oil is warm enough to make the engine easier to start on a cold day.
Adding the drain cocks will be good insurance.

 

[TyeeMan]

There would definitely be enough water to cover the element. My guess is there is water to the top of the block, maybe even enough to get into the head.

I kind of like the idea of using the boat as daily transportation. Sounds kinda fun!

 

[wahlejim]

There was a discussion on an earlier winterizing thread about ball valves. I think the general consensus was that for most people, 1x per year isn't a big deal to pull plug compared to another failure point (ball valves can get loose and open themselves if not locked in place or the seal inside can fail. It is not catastrophic, more of a drip at first so you have a warning that it is time to change them). In your case, I would use ball valves in the winter and switch over to threaded plugs when you are confident winter is over. Draining the block and manifolds would take less than 5 minutes.

If you do go i/o, do ALL maintenance items when you get it, ESPECIALLY any outdrive related items (bellows, gimbal, raw water pump, etc.) These are items that would require the boat to be out of the water and with the exception of the pump impeller, these items will last you 7-10 years before they need to be addressed again.

 

[Mechmagcn]

I kind of like the idea of using the boat as daily transportation. Sounds kinda fun!

We've been doing so for over 5 years now. Only time it's been really tough was last winter, the oxbow lake we live on froze over. Our commute is usually about 3-4 minutes, but breaking ice it turned into 20-30. I work at a small State Park where the marina is located, I can almost see my house from work, but if I drive it's 33 miles of gravel roads and river bottoms. It's takes 1-2 hours in good weather, hence the boat ride.

 

[Scott Danforth]

I would almost take a snowmobile (because if you have the right sled, you can cross open water as well as ice)

Just dont use yamahas....the belt gets wet, they loose drive.... you loose forward momentum and you sink :facepalm:

 

[Bondo]

I would almost take a snowmobile (because if you have the right sled, you can cross open water as well as ice)

Ayuh,...... Or an Airboat,...... Buncha these up here in the islands,......

 

[Mechmagcn]

I would almost take a snowmobile (because if you have the right sled, you can cross open water as well as ice)

Well.....as far as I know there's not a snowmobile anywhere near me and if I need one, this southern boy is headed south! :rofl: