Single point drain winterization

[Lou C]

we don't know exactly how it's plumbed because most of us have older boats that did not have this system. However, anyone who has had any experience with winterizing cast iron engines, knows that when cast iron rusts (and fresh water guys yes it rusts in fresh water too) it flakes off unlike aluminum, and those flakes will clog drain holes. So when Merc came up with this system, which cannot be easily rodded out unless you disconnect the hoses from the block and manifold drains, it seemed like a BAD idea unlikely to work for more than a couple of years.
It all comes back to the same thing, inboards should be closed cooled, at least a half system. What Merc did was jury rig this foolish system, bound to clog, all to avoid a simple heat exchanger. This is why I'd never buy a late model I/O. This is bad and cheap engineering, nothing more complex than that. You have closed cooling, you can simply hook up the winterizing tank, with an livewell or bilge pump to pressurize it, and then your raw water hoses, impeller, raw water side of your heat exchanger, etc are full of antifreeze. No pulling out seats, straining your back to reach buried drain plugs, etc etc. Take a look at how many hoses are on a simple Volvo half system, vs this confused collection of hoses, plastic fittings etc. The closed half system has nothing more than a heat exchanger, a new thermostat housing, and about 5 hoses depending on the application. Longer lasting engine, easy to winterize, simple design.

Just say NO to Mercruiser's foolishness and ridiculous cost cutting. I bet if you totaled up the cost of the hoses, plastic parts, distribution housings etc, its only a few hundred cheaper than an aftermarket closed half system.
Even though they are the market leader, some of their engineering and product planning is quite lacking in my opinion.

 

[Mcfltfyter]

I've read that converting to closed cooling isn't recommended after years of rust and scale accumulation, so I think I'm stuck with the open system unfortunately.

 

[Mcfltfyter]

Hoses 11 and 12 are 1-1/4", 8 is either the same or 1-1/2". I'm not really concerned with the inlet hoses clogging, it's the actual valve I'd be concerned about.

 

[Lou C]

I've read that converting to closed cooling isn't recommended after years of rust and scale accumulation, so I think I'm stuck with the open system unfortunately.

that's true, the time to do it is when you repower. That's why I keep saying it should be STANDARD. On a $50,000 new boat, they could include this don't you think? People pay more than what closed cooling costs for all kinds of un-needed junk. If it were standard, people across the South would not be scrambling for new engines now @ $6000 installed price in some cases!

 

[Scott06]

Hoses 11 and 12 are 1-1/4", 8 is either the same or 1-1/2". I'm not really concerned with the inlet hoses clogging, it's the actual valve I'd be concerned about.

The drain is the same size for all the drains on a multi point system so likely it would work. If you are concerned, Then drop the hose next to it. Bottom line the system is convoluted.

 

[Scott06]

that's true, the time to do it is when you repower. That's why I keep saying it should be STANDARD. On a $50,000 new boat, they could include this don't you think? People pay more than what closed cooling costs for all kinds of un-needed junk. If it were standard, people across the South would not be scrambling for new engines now @ $6000 installed price in some cases!

They wouldn't be scrambling fo rnew engines, but their heat exchangers would be cracked. Im surprised more folks dont drain being that it is not unusual to get some freezing temps , just not like it was this year. Even with 5 points I can drain mine in about 10 mintues for a basic freeze protection

 

[Lou C]

while that is true, it is so much easier to winterize it with the tank full of AF you really don't have an excuse to leave it full of water!

 

[Mcfltfyter]

I'm trying to extend the season beyond 2 months, and trying to avoid pulling hoses and pumping antifreeze 10 times a year. If it is always drained, there is zero chance to forget.

 

[Lou C]

with a heat exchanger it is easier to drain. one drain on the H/E. raw water intake hose gets drained, manifolds and/or elbows get drained.

 

[Mcfltfyter]

with a heat exchanger it is easier to drain. one drain on the H/E. raw water intake hose gets drained, manifolds and/or elbows get drained.

You've convinced me, I'm now going to repower with a closed system.

 

[Lou C]

With Merc you have a choice between a full system (includes exhaust manifolds) or a half system (engine only, exhaust manifolds remain raw water cooled). The big advantage of this as I said is ease of draining, you can drain one of these just having access to the heat exchanger & raw water intake hose which is usually mounted up high in the front of the engine, and the exhaust manifolds, if a half system, or exhaust elbows if a full system. There is no need to take apart the rear of the boat to get at the low down drains on the block and disconnect the bottom end of the big hose connected to the circulating pump. So the way these should have been set up, simply is closed cooling and a remote oil filter mount. Both make the maintenance much much easier and faster.