Roger B

I am not sure if it is better to ream the bores before or after drilling the ports?  For the sleeve bore I tried running the reamer through again after the ports had been drilled. The rotor bore was reamed after the ports were drilled as I had done for the diesel injection pumps.

The rotor and the sleeve were then lapped with 5 micron  diamond paste. The rotor was finished to 5.98 mm along the length as well as I could measure with a micrometre. The sleeve was lapped out until the 5.97 mm pin gauge would pass through and then step by step until the rotor would just slide in.

Next lap the rotor bore to fit the shuttle parts.

Picking this one up again. I had some problems with tapered bores on the nominal 5.95 bore. Unusually the entry was on size and the exit was 0.03 – 0.04 mm oversize. I wanted to make a longer brass lap to finish the outside of the rotor but found that the bore was tapered  After a number of experiments I am still not sure of the root cause. I thought that I had a fairly good understanding of reaming from my diesel injection work. Another 5.95 mm reamer from a different source and adjusting the spring loading on the floating reamer holder seemed to help.

Having, hopefully, solved the reaming problems I started on a new 6mm external lap, rotor and sleeve.

The parts were made much as before.

Running nicely and a good save on the crank web     

Glad to see you back on this build  The valves and cam followers look good   

Welcome to the Forum