I am breaking down a Daytona engine that sat for two plus decades. Apparently moisture got into the cylinders. The top of the pistons are visibly rusted. it looks like the rust is just at the top where the rings are located.
Any ideas on how to free the pistons?
Thanks
Soak them in gas or diesel.
Vibrations work too. very light use of air hammer. (LIGHT!)
I'd start with something like Marvel Mystery Oil. Let it soak for a few days/a week. I've also use Evaporust, but the piston was way too seized, so I can't speak to it's efficacy.
Thanks guys for the info.
I'm going to start with evaporust. I'll be able to pool some on top of one of the two pistons. The other piston is at the bottom of the cylinder.
I split a 400 motor last year that had sat for more than 15 years with water in it. I tried soaking with all sorts of concoctions and even sitting a fire in the top of the pistons as I saw mentioned on in a few threads.
The crank was completely frozen as well and nothing would budge. In the end I split the cases, cut the rods with an acetylene torch, removed the barrels. That way I could support the barrels on some wood and beat the pistons out with a BFH and another piece of wood on top of the piston. They were well seized and rusted and took some serious persuasion.
I cant find any more pics, but this was just what was loose at the bottom end when I split it.
Water in some places doesn't cause me a lot of concern. Most journals will hold an oil film for years protecting from corrosion. But, when around gears I worry about pitting the teeth.
Letting it sit too long Russell! Here's what it looked like around Y2K.
I was able to free a h2 piston from a cylinder using PB Blaster and a piece of hard wood and a mallet. I let the penetrant soak for a week and then placed the piece of hard wood on top of the piston and let the mallet do the rest of the talking I cut the piece of wood close to the size of the bore. Square cut and about 8" in length.
Hawaii-Mike, actually the Daytona engine with the stuck pistons is from another Daytona. The Daytona that I bought from you still looks pretty good. That engine is currently out of it and has been rebuilt. It should be back on the road again soon.
Hi Russell,
That's good to know.
I used a 50/50 mix of brake fluid & kerosene on a bike that had sat for the best part of 40 years, came free quite easily after a few days of soaking.
1 cylinder being at the bottom of the stroke will make it harder though, you may end up needing to space that cylinder up as the other frees off if the crank isn't seized
Best mix that always works.
50/50 acetone & trans oil. Pour into the cylinders let sit a few days.. it break free then for sure.
Patience and the above mixtures will work, eventually. Making a piece of wood or hard plastic helps when its time for the beatings.
Did a Lambretta last year that took about 3 weeks of soaking with all sorts of stuff, think I even heated some up.
All came apart eventually, heated the piston submerged in diesel outside for an hour on a hotplate in an old saucepan or so and got the rings out. Light hone and it actually runs with all the original parts, it was a see if it works thing. After all the effort to get everything apart, I figured it'll be easy the second time:)
Did check the flashpoint, monitored temperatures and probably had it hanging so it wouldnt rest on the bottom.
If nothing works,
1. Tap the cylinder Holes with M14 X 1.5 to maximum Depth.
2. As the Tap go inside it will touch the Cylinder stud which will lift the Cylinder up. Do it on diagonal Holes
Done it on a RD250 Cylinder
I finally got them both out.
I started with evaporust for a few days. I then switched to PB Blaster. After a couple of weeks I began the beat down on the pistons. I got no movement with a rubber mallet and a piece of wood. I ended up using a hammer and a heavy-duty mason chesil to strike the top of the piston. That combination seemed to move the pistons a little.
I then decided to put tie straps around the jugs to lift the front part of the engine a centimeter or so off the worktable. As I struck the pistons, the pistons and engine went down and the jugs came up. This method made it easier for me. It still took forever and was not fun.
I am hoping I didn't damage the crank with the beat down??? Anyone know how tough these cranks are?? I did find a little rust in one of the bearings, but the crank turns and is not frozen.
During the process I accidently struck the top of the cylinder/jug. Picture attached. Any idea if this jug can still be used again?? The two dings are about a millimeter deep.
Thanks to everyone who chimed in with advice. It is always greatly appreciated. I hope the pics show up.
Thanks again,
Russell
Opps. These pics didn't show up.
I would not hesitate to fill in the hammer marks with a little ultra black RTV, anneal the copper head gaskets by quenching them in water from red hot and just going for it. That really should work fine.
The ultra black will cure like a custom made o-ring seal.
Good Job Russell! I agree with Steve, the cylinders are probably okay.
Thanks Mike.
@2Steve-thanks for the info. I will give it a try when the that time comes up.
Ouch. That's a bit of a mess but the crankcases are still good, so you got that going for you.
Looking at the corrosion on the piston, it is highly likely that the barrels will have matching damage and will probably need to be bored to clean them up. Run a ball hone through the barrels and see how they look under the film of rust.