Another winterize question

[Scott06]

Does a 350 SBC have 5 drain plugs too? I found 4 - one on each side of the block and one on each exhaust manifold. If it does have 5, where is the 5th?

Mine has a 5 th blue plug in the big U hose between the thermostat housing and the block circulation pump. Has a T fitting stabbed in the lowest bend to drain it without pulling the hose. Kind of a nice feature

 

[tpenfield]

Mostly on a closed cooling system you are protecting from freezing . . . as far as corrosion, not as much of a concern. I run -100˚ F AF through the open side of my closed cooling system. There is a sea water strainer, sea water pump, the oil coolers, the HE itself, and the exhaust elbows.

I used to run the -50˚ F stuff, but found every year the sea water strainer (plastic) was cracked (from freezing). Once I switched to the -100˚ f stuff no more cracked sea water strainers.

It seems that the -50˚ F AF rating is for a pipe burst . . . however at about -20˚ F the softly frozen AF was enough to crack the bowl on the sea water strainer.

 

[Lou C]

Interesting Ted! I put a gallon of -50 and -60 in the freezer set at zero*F many years ago and found they both get hard; the -100 stays liquid. In fact West Marine which sells all 3 does not recommend -50 or -60 for temps close to or below zero. They recommend only -100 for those temps. So I only used -100 all these years and when I could find it I use Sierra no tox PG antifreeze, mixed 50/50 it gives freeze protection down to -26*F. You can go 60/40 for better freeze protection. For some reason the -100 was hard to find this year.

 

[RaceCarRich]

West Marine literature states that the -50F (burst strength standard for copper pipe) will burst a PVC pipe at -10F and does not recommend-50F for water systems when temperatures are at or below -10F. I’m guessing the plastic sea strainer is weaker than PVC.

Around here West Marine has pallets of pink on the floor as the big seller and shelved cases of -60F & -100F.

 

[RaceCarRich]

West Marine Antifreeze Guide

 

[ricovw]

Good point about the heat exchanger/closed cooling. Depending on if you have a 'half' system or a 'full' system, here are some diagrams . . .

View attachment 328048
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View attachment 328049
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Closed cooling is easy, since the flow through the 'open' side is more sequential than a raw water cooled engine, and there tends to be less water to purge. Full systems are easier to purge than half systems.

Looks to me like I have the 'Half Closed' system. I drained the manifolds from the plugs on each side (4.3 Merc). It looks like it drained the heat exchanger at the same time. The 2 valve on the engine block I left because they are holdning back Coolant. I removed the plug on the heat exchanger to verify there is no water. Seems to me, according to the drawing of a Half Closed system that there isn't water any where else? Am I wrong?

 

[Lou C]

Well there is still the raw water intake hose that leads up to the heat exchanger, I'd disconnect that hose at the H/E, and put the drive down, then fill it with -100 marine antifreeze to push out any water in the hose and any coolers that are in line with that hose (p/s or fuel cooler).....