To be hones it has not taken too much of either, mostly time and it will be working for a living in my 1913 Humber Barge where it has been since the 1950s.

I am well on with the rebuild the liners and pistons are now fitted, I am at the stage where I need to check the piston to head clearance. It is clear in the manual how you do this with a small piece of lead, and I have loads of spare shims as well as three gaskets.

What is not clear though is when you fit the head to measure the lead do you fit a gasket or assemble without one. If you do fit a gasket do you use a new one as the operation will compress it so I would have thought it would not seal as good when you assemble finaly.

Next question, how tight should the liners be. The good book says to lap them in to the top of the block so i presume they should be free to spin. They fit fine until just before the shoulder at the top goes in to the block, there is a small step in the liner at the top and this matches a machined section on the block.

I understand that this is where the liner seats in the block so must be a good fit, it is really tight and the liner does not want to go down. I have one liner in the freezer and I will heat the block tomorrow and try again I don't see how the liner can be lapped in fit its that tight though.

It is more complicated with the liners not realy being the right ones for the engine.

The part number for JK & JP 6 liners is 616-252/6 so they do seem to be different. My 1st thoughts are to get the tops machined however they seem to be fatter as well. I have a Lister service bulletin which suggests that the flange should be !/2 inch thick leaving a 6 thou protrusion.  The flanges seem thicker than this and I am not sure how well I could get them machined to enable the correct protrusion

It also mentions a later revised liner with an additional stepped lip at the top of the liner that protruded through the gasket to locate the gasket and ensure that the head locates properly. It seems to suggest that the head actually touches the top of therevised  liner to prevent the gasket from being over compressed.

I have been speaking to some commercial barge owners and they say the JK6 and JP6 was very prone to head gasket failure although lots of older barges have them this revised liner and gasket seems to be an attempt to prevent this. There are dire warnings about not using early head gaskets.

The Lister service bulletin also says that the liner should be lapped carefully in to place and this is what I was preparing to start when I found that they were to large at the top. The one I tried fit most of the way perfect but was very tight to turn the further it went in I think it would have been impossible to turn to lap if it had have gone all the way in, is this normal and just a matted of cleaning and lubrication.

Thank you i suspected that was the case

I have been offered  some straight top liners at a reasonable price, I need two of the six for sure but I haven't got round to cleaning the others up yet. The liners in the engine were stepped top and I understand that these were the later ones introduced to overcome a problem with head gasket failure. The lister manual I have says that either can be used as long as they are all the same

So my question is are the straight top liners any good or are they more prone to head gasket problems.

I am struggling to get the pulley of the front of the crank (lister JK6) its a cast iron pulley and there is not much room to get a puller in. I have it soaking in diesel and have left a 2 leg puller on over night.

Does anyone have any tips would heat help.