The Stovebolt Site Forums The Shop Area Engine Shop Hot water to unseize an engine

I have been pouring rust penetrator into each cylinder for a couple of weeks, the engine will not budge.

Has anyone ever tried to pour near-boiling hot water down the thermostat housing (thermostat removed) to unseize a straight-six engine?

The theory, as I am told, is that the hot water will heat the exterior of the cylinder wall (via the water jacket) and thus, through expansion, break the hold the rust has on the piston rings.

My concern is that if I cannot completely drain the water from the engine (valve near bellhousing very is hard to reach) the block will crack when the remaining water freezes. Will cranking the water pump evacuate enough or all of the water?

sambear,

I haven't heard of the hot water trick. It seems there wouldn't be much 'hot' left in the water by the time it made it into the dark recesses of the block...who knows!

Not coming from a freezing part of the country, this theory might be all wet, but if the water weren't constrained on all sides, it seems like it would grow in the unrestrained direction and do no harm to the block.

A plastic ice tray in the freezer doesn't rupture each time it's filled because the water can push upwards as it freezes and expands...does this sound right!

Stuart

The only way to get all the water out of the block is to take off the water pump, open the rear block drain, and tilt the engine until it runs dry. Cranking the water pump leaves about 1/2 the water in the block and could/will damage the block if it freezes. However, you could add antifreeze to it later and circulate it around.

I'm pretty sure it won't work though. You will have to add about 40,000 btu's of heat to bring a block up to operating temperature, which is about 60 gallons of hot water.

Besides, its probably the rings which are siezed to the cylinder bores, and those have a gap so they will just expand and contract with the cylinder walls.

You can get most of the water out by draining the radiator & raising the rear of the truck real high. You should be able to drain the block. You can either remove the plug or the petcock & poke a wire up in the hole if it is pluged up. If you have ever pulled the head on an engine that was stuck real bad you will see you are waisting time fooling with it. They are full of corrosion. If you do free it up it won,t be any good. It,s probably time to pull it out & rebuild it.

If you're bound to try it, use hot coolant mixture that won't freeze,
Scott

sounds like its time to tear it down to me. you've spent a few weeks trying to get it turn, it only takes a few hours to take the head off. if its stuck that tight, the chances of it running, even if you get it broke loose is pretty slim.

I agree that a little hot water wouldn't do much. But its worth a shot. But I also think you pull the head and see what your dealing with. Also ever think about carefully heating it with a torch just ever so gently and carefully not to burn or melt anything. That has broke nuts loose before this is just on a larger scale

A friend is trying to get me to boil a 50:50 mix of anti-freeze and water and pour that in. He thinks that will develop a little more heat and provide less concern if left in the water jacket.

Thoughts?

When i have a motor that is stuck i use CRC penetrating oil and it works every time.you need to fill up the cylinders and let it sit for a week and hit the starter ever once in a while It will brake loose.I had a 350 that sat for 25 years and was frozen solid and i got it running again CRC works man try it.P.S DO NOT PUT THE SPARK PLUGS IN IF YOU FILL THE CYLINDERS BECAUSE YOU COULD HYDRAULIC A ROD IF IT TURNS OVER!FLUID DOES NOT COMPRESS.Hope you get it un frozen.