I had looked into various options for the missing bed casting as the owner had also asked me about that, options ranged from getting a family member to 3D print, using Craftcloud to 3D print in a reinforced filament as well as an Aluminium print together with a fabrication much like I had used on the smaller versions I built earlier. With the decision now being mine I went with a fabrication.

The side plates were shaped on the manual mill as the two curved cutouts were regular arcs so easily done with a boring head, holes for cap head screws added and then I tilted my vice so that a face mill could be used to add some draft angle to get the cast look.

The two end plates were drilled and tapped for M4 screws and I milled a pocket in the bottoms to accept a smaller offcut of the 12mm aluminium for the feet. The two plates were held back to back which kept the setup simple, full depth 12mm cuts.

Once the four main parts were screwed together with some JB Weld in the joints I clamped the base to an angle plate mounted on the lathe’s cross slide to cut the draft angle on the ends.

A bit of car body filler in the screw holes and to form fillets in the internal corners, rounded the external corners with a file and it does not look too bad.

Jumping back a bit in the order of work the piston and conrod were not too bad so all I did to them was add a grub screw up from the open end of the piston to lock the gudgeon pin in place so that it could not move sideways and score the bore.

The CI rings had been fitted to the piston but when I went to try the piston in the bore I could not get it in, turns out the rings had not been gapped so would never have gone into the bore. I gapped then to 2 thou but have actually left them out as the engine is only likely to be run for display and no rings makes for a smoother slow running speed.

The crankshaft was a good fit on the big end and straight. However each side was a different diameter and both were tapering in towatds the middle. As the pedestals with their integral bearings had been machined they obviously were a bit slack by the time they had been slid down the shaft. I did not really want to make a whole new crank, pedestalls and bearings so did the best I could. Which was cutting off excess crankshaft length and making the flywheel bores as tight as possible which seems to have worked as I can’t see any wobble.

The faces of the bearing were rubbed down on some Emery to close the bearings up a bit. I also found that the machined bottoms of the pedestals were convex so they rocked, easily fixed by taking a skim off the bottom which also made them the same height which they were not when I got them! Holes were drilled and tapped for oil pots which I made to match the three which were included for the cylinder.

It should come as no surprise that the 4 stud holes to hold the cylinder to the bed were all off both where they started and even more where they had wandered to. Same for the pedestalls which were not spaced equally. I ended up clamping my new bed to the mill table and adjusting the parts until the crank turned freely before using a drill to spot all the hole positions.

That was not totally successful, as although the holes entered the base in the right place it was impossible to lower the cylinder down over the studs so the holes in the cylinder needed to be opened up.