350 mag mpi closed coolant flush. Will one block drain empty the whole block?

[William Miller]

obviously the block drains are not easy to reach.

Second question.
How much coolant does the block hold below the water pump?
I can't find this specification anywhere.

The engine circulating pump feeds the block on each side below the head. Are the two sides of the block completely seperated?
Coolant goes up thru each head and combines again at the intake manifold below the thermostat,.

I just put my refurbished mains back in the boat with new "Monitor" full system.

 

[William Miller]

 

[scoflaw]

Not sure of actual volume but the water jacket is about 3" lower than the water pump openings.

yes you need to remove both block drains to get it all.

 

[Skuza]

No. Both halves are separate reservoirs sort of. It’s surprising how much comes out. Messy job.

 

[William Miller]

Thanks
My engines are clean but the guys that make the closed cooling system recommended running it on straight water a few times to get any salt suspended and flushed before filling with 1:3 coolant.
I need to empty the block or know how much water it holds.

 

[scoflaw]

The ratio isn't critical, I would be more concerned about making it strong enough so it doesn't freeze over the winter. My 502 takes 4 gallons exactly.

 

[William Miller]

Thanks, Monitor had a good reason for suggesting 3:1.
It takes it to -5 or so.
But I assume that can change as the coolant may degrade.
So I think I'll flush it them a few times. Drain from the water pump hose.
Add 2 gallons coolant and top off with water.

Thoughts?

Whats your procedure winterize the raw water side.
I have installed thru hulls. The strainers have drains.
I also have crank mounted raw water pumps. Impellers take 10 min.
I got new cool fuel housings with the drain plugs.

I'm thinking if I pull out the impeller. I can drain most of the exchanger and elbows.
Blue plug on the cool fuel.
I think my elbows have brass plugs at the top.
Maybe fill it with winter antifreeze from there until it flows thru all the hoses all the way down to the strainer / seacock.

 

[scoflaw]

2 gallons of concentrate would make it 50 50, that's what I run. I just pull the blue plug on my CF2, which is the lowest point on my system, and pull the hoses off my manifolds. Connect everything up and pour a gallon or 2 into my strainer with motor running.

 

[William Miller]

2 gallons of concentrate would make it 50 50, that's what I run. I just pull the blue plug on my CF2, which is the lowest point on my system, and pull the hoses off my manifolds. Connect everything up and pour a gallon or 2 into my strainer with motor running.

I'm looking for the capacity on the closed side with heat exchanger.
If I drain the pure water out by taking off the lower engine circulating pump hose it will drain everything in the block above that. So, how much is in the block in the water jackets below that level?

 

[William Miller]

2 gallons of concentrate would make it 50 50, that's what I run. I just pull the blue plug on my CF2, which is the lowest point on my system, and pull the hoses off my manifolds. Connect everything up and pour a gallon or 2 into my strainer with motor running.

This is what I ended up doing. Thanks!
The only issue was the pump sucked the coolant out of the strainer faster than I could get it out of the jug.....