I have a friend with a 496 mag ho. He stores this boat inside every winter but this year was slow to tow it to the storage facility. With the boat sitting outside we had hi/low temps of 32/19, 34/24 and 34/23. I would assume the block is safe but the manifolds? Heat exchanger? Anything else he should be concerned with?

If you are unsure, go to Petsmart and get 2 (or 3) clip on Lizard heaters. You clamp them on and either put them on a lamp timer or leave them on.


You will be surprised when you check on your boat and the engine is WARM...

If everything was drained and blown out of freshwater shouldn't be a problem.

Nothing was drained. It came out of the lake and sat for almost 2 months.

The Heat exchangers need to be looked at IMO. There is a little hand pump under the hood that could have been used.

Is this 496 a closed coolant system? If so I would imagine it would be just fine. If not, it really doesn't matter what engine it is, doesnt take much to do major damage. Either way, I hope it's ok!

Three days at those temps he should be at the edge on the very concerned list . Probably not long or cold enough to do damage but he better move on it soon . $$$$$$$$$$$

I'd check it over, but chances are it is okay.

Agreed. Doesn't take much to freeze the small amount of water in engine blocks acting like freezers!

The 496 is a closed system so the block has antifreeze in it all year. The heat exchangers have hand pump for blowing them down, but the damn thing needs winterised.

I have antifreeze in my exchanger this time of year.