draining block on mercruiser 454 for winterization

[whitehouse montego 3257]

Hello there. First time winterizing on my own. Had a mechanic assist. Question: port engine, drained block on inside (closest to me) first. When draining outside of block, very little water came out. I did poke inside also. Is this common? are the passages connected at all?

 

[Stephen]

I assume raw water cooled (no antifreeze). Yes, the drain plugs being fouled with crud and scale is common. In the future, keep a #4, #6, and #8 nail handy and thouroughly have at it with the scale as the water is pouring out of the drain. Start from the highest drain and work down so you have water pouring out of all of them as you clean them. I also pour -50 degree camper antifreeze through the engine first to make sure there is no possibility for raw water being left behind to freeze.

 

[whitehouse montego 3257]

Thanks for the info. Yes, raw water cooled. I'm heading back down tomorrow to open that one drain plug and if no AF comes out, I plan to poke around again as there was very little water the first time around with the mechanic and I'm a bit concerned that there should have been more water draining.

 

[JimPend]

I use antifreeze in mine, I don't pull any plugs. I saw too much rust in the engine when I got boat. It's been going good for 25 years since then.

 

[jtybt15]

When flushing the cooling systems of cars, I sometimes pop the freeze plugs. I have found rocks and a fair amount of gravel from the casting medium still in the water jacket. They can create a dam, preventing full drainage.

Having raw water cooling, it's even possible for rust scale to build up in the water jacket creating a 'dam'.