Valves

 Cylinders #1 and #2 with their valves and push-rod tubes in place.












Valves were made from 1/4" 304 stainless steel bolts 2 inches long. They were used in preference to bar as the bolts were work hardened from forging which made them easier to lap to size. Valves for cylinders #3 and #4 are shown below, they still need the retaining clip grooves machined.

The bolts were centred on the thread end first then the head was held in a three-jaw chuck and turned to 4.03mm. 0.03mm allows for lapping to parallel. The lap is shown with their silicon carbide inserts one course, one fine. The lap is held by hand as the valve spins in the lathe. Lapping took about five minutes per valve stem.Once the valves are lapped to size the head of the bolt can be turned into a valve head.

Here is an entire valve assembly from the #1 cylinder head. The valve guides are made from cast iron salvaged from a storm water grate (Trapezoidal in section!) and turned to round. The finished valve has a groove turned in the end to fit the c-clip. The c-clip for the keeper is made from a piece of 1mm silver solder (the long length of wire in the background). The keeper is stainless steel 10mm OD and the spring is commercial. To assemble, the spring and keeper are compressed on the valve stem and the clip pressed in the groove, it is held in place by a recess in the top of the keeper.







The inlet and exhaust ports have been counter-bored to accept the manifolds. The valves and rockers will eventually have a cover, this bolts to the plate shown on the left head.









Push-rod tubes have been installed. Valves in cylinders #1 and #2. The 'castings' at the bottom of the push-rod tubes have been turned from cast iron and serve as the bearings for the cam followers.

The threaded hole for each spark plug can be seen in between each cylinder's push rod tubes.