Cylinder liner sealing

[Gordon]

What should be used to seal a cylinder liner in a cylinder? I have a liner made from DOM tubing in a steel cylinder. It has holes in the side for intake/exhaust/plug. I put it in using JB Weld and it is leaking around the spark plug hole. I am sure that when it is inserted it scrapes off most of the JB Weld. It is a rather tight fit in the cylinder. It is not a press fit but required some tapping to get it in place. Something like epoxy would probably flow better but that probably would not take the heat. The alternative is to remake it in one piece.

 

[Charles Lamont]

Because JB Weld is viscous and has a filler I don't think I would use it for a tight fit. Loctite of the right grade would most likely be better, such as 620 or 638. Is there any cooling?

 

[Gordon]

No cooling. I have not been able to get this thing to run long enough for it to get hot.

I think that I am leaking around the spark plug hole but I cannot verify that. I have put compressed air at 20 psi into the spark plug hole but cannot find any leak. Next step may be to remake the whole thing as one piece.

 

[dsage]

Are you back at the (damn) Atkinson again . I put mine aside but I'll get back at it. Good luck.
I just had a similar problem on a small steam engine a friend gave me. The cast iron sleeve was already epoxied in place in the aluminum block so I didn't want to attempt pressing it out.
What I did was take a small piece of brass hobby tubing (Or you could machine your own to size) and slip it in the hole so that it makes a path from the outside of the engine right into the cylinder. It was a light slip fit with enough room around it for JB weld. It effectively bypasses the interface of the sleeve and the block.
I do understand you are talking about a spark plug hole so it's threaded etc. and I've forgotten the mechanical details but maybe something like that could be inserted in there without affecting the spark plug setup?
I assume your intake and exhaust flanges might have the same issue and the inserted tube would work there as well since they are just a smooth passage with no threads.

As for heat I wouldn't worry about it. JB weld will take a lot more heat than that engine will produce and the cylinder is cooled by the water hopper.

 

[Lloyd-ss]

@Gordon , can you seal it well enough to put it under water to look for bubbles?

 

[mrehmus]

What should be used to seal a cylinder liner in a cylinder? I have a liner made from DOM tubing in a steel cylinder. It has holes in the side for intake/exhaust/plug. I put it in using JB Weld and it is leaking around the spark plug hole. I am sure that when it is inserted it scrapes off most of the JB Weld. It is a rather tight fit in the cylinder. It is not a press fit but required some tapping to get it in place. Something like epoxy would probably flow better but that probably would not take the heat. The alternative is to remake it in one piece.

View attachment 163431

 

[mrehmus]

The best way is to have a shrink fit. Just heat up the cylinder and push the liner in.
Here is the description of how to do it from my magazine:

 

[Vietti]

I have had good luck with Locktite wicking thread locker. Saw a suggestion here and it even sealed up some leaking valve guides. This stuff wicks so well it may end up locking up things you did not want locked up!

 

[Nerd1000]

Loctite 638 retaining compound is what I've used. It's very strong.

 

[Jasonb]

I tend to use Loctite 648 which was the higher temp option but 638 is not much different now

 

[Gordon]

At this point I have determined that it is leaking around the spark plug. There is no good way to remove the liner to reseal it so I am in the process of remaking it as one piece.

 

[Vietti]

Why not try the wicking locktite-at this point you have nothing to loose??