Part 12+1 By Vince Cutajar

I had a plan for machining the cylinder.

As the 4 jaw chuck was still installed I faced the top of the cylinder and then machined the base of the cylinder to the proper height. At least this way both faces should be parallel.

Next photo is showing why I can't use my 4 jaw chuck for the rest of the operations. I can bore and also make the fins but I cannot reach the bottom part of the cylinder below the fins.

So I am proposing to use the faceplate to hold the cylinder. For boring I will hold it with clamps and then when that is finished I will lock the cylinder to the faceplate with a threaded rod passing through the newly bored out hole and the lathe spindle. I will then remove the clamps and work on the outside of the cylinder.

I fitted the faceplate to the lathe. It has been a long time since I used it last so I checked the middle part of the faceplate (where the casting will be sitting) for trueness. Plus/minus 0.005mm. Good enough for me.

I then held the casting to the faceplate using a 14mm threaded rod through the lathe spindle and using a DTI on the bottom round section of the casting, centred it as much as I could considering it is still a rough casting. With the casting centred I then clamped it to the faceplate and removed the threaded rod.

I then started the boring operation.
the boring operation and then used a threaded rod through the lathe spindle and cylinder bore and tightened it on a thick aluminium washer.
Then started work on the outside of the casting.
Cleaned up of the fins at the specified 10 deg taper. There where some imperfections in the casting which I did not remove because it would have meant making the fins smaller. I will have to just live with it.

All that remains is the clean up of the sides of the base on the mill.

Just could not resist and put the cylinder on the crankcase to see how it looks.

I needed to mark the centre of a hole in an already existing rough cast hole. I used a piece of round brass jammed it in the hole and now I have something solid on which to mark the centre. Thankfully, I had left marks on the platform of the crankshaft axis and the split between the crankcase halves was the other axis used to mark the centre.
Located the rotary table under the mill spindle using the coaxial centring gauge. Clamped the crankcase to the rotary table making sure the previously marked centre was in the centre. Milled the pocket in the crankcase and did a trial fit with the cast iron liner. Using the same setup cleaned up the slot where the con rod passes in the same pocket.
Next the cast iron liner to be inserted into the cylinder. I thought I would try the gentle approach first and if that did not work than the brute force approach would be used (with the press). Put the liner in a freezer bag and put it in the freezer (with permission from the wife) for four hours. I then put the cylinder in the oven (also with permission) for about 45 minutes. Took out the cylinder from the oven and the liner from the freezer and the liner just slipped in the cylinder and left it to cool off. Checked it after cooling off and the liner does not move. I did not think it would be that easy.

The lip of the liner is visible at the top of the cylinder and at the bottom of the cylinder the bottom of the liner is also visible. This part will go in the pocket I milled out in the cylinder platform.

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