Had the same problem. What worked for me was heating the inside of the liner with a blow torch. Slid right out. Use heavy gloves, because the casing will get hot!
Not hot enough, I assume, to remove the temper? (That would be somewhere above 350F)
No. I just put the flame in the hole, but do not allow it to touch anything. I just heated it until the casing felt a little warm through my leather glove, then poked the liner right out with a piece of PVC pipe.
This is what I do. I've talked with several folks who do say that grease will act more like glue if it gets hot enough and will be hard to remove from the case. So they don't use grease. But I was also taught by my motor mentor to use lots of grease to help fill any air void between the liner and case. So I've always used liberal amounts of brake lining grease. Usually liners slide out easily but every once in a while I have to get the dowel out. I do make a sharp edge so it grabs the liner. Once under the liner a rubber mallet will drive it down the length of the motor case, splitting the liner open as it goes. Occasionally the dowel will break at the end and I'll need to resharpen it. I then use Ballistol to clean the cases and it works pretty well.
Probably nothing, but if it's deep enough, you create a void between the liner and the metal that could overheat and bulge the case. Someone will be along momentarily to tell you I don't know what I'm talking about. And that may be true!
Wildly late addition to the thread but I came across it today while looking to solve this same problem and wanted to add some clarity I found missing.
