Rather than give a blow by blow account of my engine rebuild go to Mark Langford’s excellent website and follow his rebuild from there. I will show some pictures of my rebuild with some additional comments.
Rather than build the engine in the shop along with the sawdust, I decide (with permission!!) to start the rebuild in the kitchen. I first bolted both crankcase halves together with the crankshaft and camshaft complete with new bearings.
Some old waste pipe being used as the inlet manifold pattern. I intend having some aluminum tubing bent to shape. I am hoping that I can weld the bend to the flange rather than have the ‘tee’ piece as shown.
I changed out the mounting bracket to an aluminum plate. I need to fit the tacho sender on the other side of the engine so I took the opportunity to make the brackets the same type. I borrowed the idea from William Wynne’s website.
I have found that the Harley Davidson CV 40 Carburetor needs priming or full choke at each start up. If I put my hand over the carb mouth at start up it fires up OK. As soon as the prop blast hits the carb when I remove my hand the engine dies. Too much air I think. I will make up a choke as part of my air box to see if that helps with the starting. I think I need only the choke or primer, not both. Ignition is set to about 8 degrees so should give me about 30 degress when WOT. I also intend making the ears smaller in height so that they fit within the cowling. I also find that the starter motor doesn’t like anything except a fully charged battery. The starter motor jams sometimes if not fully charged. Could be some tuning on the timing is required.
Changing the timing improved the starting considerably. I also installed an Odessy Battery which has not needed charging. I have changed the carb out for a borrowed NAS-3. I also borrowed a three blade prop and the combination is working very well. Presently the engine turns static at around 2800rpm. Oil pressure is in the 45 – 50 psi , the oil temp and CHT not very high (too much cooling with no cowling?) I am thinking of purchasing a NAS-3 or MA3-SPA. The CV 40 is OK but needs a lot of adjustment and fiddling about. The NAS-3 bolted straight on with (at present) no adjustment needed. Click on these small images for some engine runs. These runs are with the CV 40 still installed