Is it bad to leave the engine drained after draining the water, then flushing it with antifreeze? All the shops in my area leave the RV antifreeze in the engine for the winter.
I moved this to the I/O and Inboard section as I am assuming that's what this is. Be prepared for a variety of opinions, although the simplest one is air doesn't freeze . . .
The thinking (as I've heard it) is that an empty block will rust where a block full of antifreeze will not. You will hear arguments either way but I promise you that if the block is properly drained it will last a very long time. If you want to fill it with anti freeze for piece of mind then that will work also.
Do what you feel best with because there are varying opinions on this matter.
air doesn't freeze. it won't rust badly if it's in freshwater nothing to worry about there it will last for years possibly the life of the boat.
and there is no mixture of anti-freeze to use. you jsut use the bio degradeable plumbing anti-freeze.
once you drain it put your plugs back in and it will also slow down the rust effect. some guys leave the plugs out over the winter. and once the plugs are out poke a wire threw the drains because you can get a build up of sand and sediment which can prevent the water from flowing out.
also when you get your plugs out tilt your tonque jack on the trailer all the way down to get the water out of the front of the engine and put your drive down to get the water out of that. I like to hit the kill switch and give it a 10 second crank to get the water out of the water pump. then tilt your drive all the way up then crank your tonque jack all the way up to get the water out of the bilge and any water that may exist in the back of the block.
I use 5gal RV antifreeze per engine, drain after. Once they're drained, I tow the boat about 5mi, helps get any residual water out of the block/heads. I also pull the manifold hoses along with removing the plugs.
After I drain the block and manifolds, I start pouring -100 till I see some come out the drains...you can actually see it push out the last of the water...then I put some grease on the drain plugs, replace em and fill the block and manifolds through the hoses...and fill the raw water intake hose till it runs out water intakes on the drive...
Keep in mind for iron to rust you need oxygen...rust is iron oxide after all...it's the oxygen in the air and water not moisture per se that rusts cast iron...so if you fill the engine and manifolds with AF with corrosion inhibitors for the winter season you are cutting down corrosion...
any marine supply place...some say the -60 is good enough but they slush up at 10 or so and I feel better with the -100 that stays liquid down to -50 (I know sounds like overkill but it's nice to not have to worry all winter)....
The amount of corrosion you are going to get in a block sitting empty is negligible. Use the anti freeze if you want for freeze protection but you really aren't doing much for the corrosion aspect. Also, please let me know how many engines you have seen that actually failed because of internal corrosion.
The amount of corrosion you are going to get in a block sitting empty is negligible. Use the anti freeze if you want for freeze protection but you really aren't doing much for the corrosion aspect. Also, please let me know how many engines you have seen that actually failed because of internal corrosion.
in salt water it happens, takes a long time but it does happen. If it was not an issue why then would Merc and Volvo offer closed cooling for salt water? My local shop told that they have seen manifolds last 7-10 years when people fill em with the good AF vs leaving dry where they might only last 5 years here...
Merc and Volvo are not the only manufacturers to offer closed cooling systems. Closed cooling systems allow the engine to run at a more efficient temperature and of course, they keep salt (or other untreated) water out of the engine itself. Depending on the system, raw water may still flow in the manifolds and exhaust system.
Closed cooling systems have nothing to do with engine storage or winterization, they are for more efficient running of the boat and longer engine life. You typically find them on more expensive engines and boats. My (diesel) boat has a closed cooling system.
I use 5gal RV antifreeze per engine, drain after. Once they're drained, I tow the boat about 5mi, helps get any residual water out of the block/heads. I also pull the manifold hoses along with removing the plugs.
The reason I am asking this question is because last year I left the block dry and I noticed alot more crud when draining the engine, the other years I left the -50 af in but our winters get down to -45 C and I become very paranoid.
