how much antifreeze?

[xort]

I'm going to winterize my engine soon. It is a Perkins 4.154 with closed cooling system. I've already changed the coolant in the engine.
I am planning on pulling the seawater feed and sticking that into a bucket of antifreeze and run the engine till I get antifreeze out the exhaust. But I'm unsure of how much antifreeze I'll need.
The boat is on jackstands and yes, I'll use the proper type of antifreeze.
How much?

[hardalee22]

Probably just a gallon, maybe two.

[k1vsk]

1-2 gal before dilution should be right - it depends on the length and size of your exhaust system and muffler volume, not the engine.

e.g., my dock neighbor and I have different boats but same engine. He uses 2 gallons mixed, mine uses close to 4 gallons.

[brak]

I used up 4 gallons for my engine. This is a non-dillutable type, and I use highest strength since it might just mix with leftover water in the system.

It really depends on how much the water volume is - in strainer, engine, exhaust hoses, exhaust mixer (the can thingy) etc etc. Better be on the safe side here.

BTW I'd be worried to run the engine on jackstands - lots of vibration that is not absorbed by boat floating in the water. But that's just me.

[Quickstep192]

If it's the first time, I'd start with a 5 gallon bucket full (or almost full) of antifreeze and wait to see solid pink coming from the exhaust. You can put whatever's left over back in the bottles and save it for next year. Antifreeze is cheap compared to engine blocks.

[brak]

one thing is - if you don't have a large enough bucket (mine is only about a gallon), get ready - open all antifreeze bottles, and make a second hole on the side (to let air in and permit it to flow more freely). My engine sucks a gallon of antifreeze in as fast or, if not careful, faster than I can pour the next one.