Then I started the con rod, this is made from 6061t alloy which has a greater mechanical strength than

the 6080 I have used for the crankcase.

The slave rod holes were then opened out to 6mm for half the depth of the rod. The big end bearing is screwed

into the rod by hand, I machined a slot and tightened with a screw driver then using an m6 end mill I relived the

bearing were it covered the slave rod holes

The top part of the rod is reduced in thickness by 1/8'' and the lower half is cut to form the angular shape.

The rotary table is replaced with a milling vice and the slots for the slave rods are cut.

Slave rods , starting with two pieces of aluminium milled to the correct thickness

After making the second rod I made the locating pins out of silver steel , these screw into the master

rod. The bronze bushes are standard shop bought .

Pistons, start of by turning some alloy round bar to a smooth sliding fit into the cylinder.
Then carefully put two piston ring grooves and one oil groove.

Still on the mill I remove some material from the inside to lighten the piston

Back in the lathe the pistons are parted off and faced up to size.

They are then put in a jig on the mill and the valve recesses are cut into

the top of the piston.

Piston rings, these are made from cast iron, a piece of round cast is turned down to the same diameter

of the piston bore. Then it is bored out to the diameter of the piston ring grooves plus a couple of thou

for clearance.

The rings need heat treating , to do this I made a small 'oven' out of the same cast iron.


the oven is loaded with rings which holds them open for a 'ring gap'