Part two by Ramon Wilson

Part one here Part two part three

A fixture was made to hold the cylinder via the hold down bolt holes. The two larger holes sit on the centres of the transfer bulge radii.

A block was set square to the mill table with a pin set in for the fixture to rotate about.

Then by rotating small movements and clamping the radius was slowly formed. Once done the cylinder was moved to the second hole and the machining repeated.

Back on the small mandrel to cut the scallops out - the bulges can be clearly seen here.

And finally - finished ready to lap.

The con-rods were made from 'Alumec 89' a very tough grade of ali.

The spinners were done in the usual fashion of a series of flats then flared using a scraper made from an old file.

The cylinder head fins were done using a home made cutter - usual silver steel, heat treated, quenched in oil - no tempering for max hardness, teeth sharpened using a worn diamond file.

Shot of the intake parts.

Needles were made from mild steel rod run down to 7BA diameter. The thread was put on by die and the tail end supported in a brass centre. The taper was then put on just by filing until the end parted.

...then finished off by the usual method of supporting it on a wood support/guide to finish file and smooth - works very well