First job today was to remove the welch plugs from the ends of the rocker arm assembly. Even though they sat in Simple Green for a number of days, I expect there to be plenty of sludge inside. I drilled a hole in the welch plug and inserted a screw. I then used a crow bar and pulled them out. I then ripped a long strip of of cotton rag, dipped it in gun wash and then threaded it through the shaft using a long piece of wire. Heaps of sludge and grey goo emerged! A little bit more time spent cleaning and they were both ready to reassemble.
The welch/freeze plug kit I bought had 9/16 welch plugs for the rocker shaft. They seemed a little big, so I measured the hole….13.2mm. This is significantly less than 9/16 which converts to 14.29mm. I decided to assume that the kit was correct, and proceeded to install a plug. It took a bit of effort to to get the plug in, but I felt it yield and then push in the hole. Once it was in I could see that the plug had deformed. I pulled it out again to have a look.
I was not happy with this level of deformation. Down to the local auto parts store for some plugs. They only had 14mm welch plugs, but they were brass which means that they were a little more malleable. I decided to machine them down to help them fit into the 13mm hole. As luck would have it I had a dyna bolt which was a perfect for the 14mm plugs. I set them up on a cordless drill and used a file to machine a lead in on them.
Success! They went in easier than the mild steel plugs, and also went in evenly. This was a much nicer solution.
I then proceeded to put the rocker arm assemblies together. This also gave me the opportunity to crack open a bottle of the Amsoil Break In Oil I will be using in the engine.
Next job was to start on the heads. Not planning to do anything radical here, just enable it to breathe the best it can to maximize efficiency. First task is to gasket match the inlet ports. I used masking tape around the studs to centre the gasket, and marked the gasket openings onto the head. All of the ports were mis-aligned vertically (as were the inlet manifold ports). First picture is the original port, next pic is a machined port. As they are inlet ports, I left them with the rougher finish off the burr.
I then spent a number of hours polishing the exhaust ports. Nothing crazy, just a general polish using the Eastwood Porting kit I bought. I also tidied up the inlets around the bowls as there were a number of steps in the flow path. I had to make up a light which would fit in the ports so I could see what I was machining. I soldered a couple of wires onto a brake light bulb and connected it to a variable power supply. I didn’t take many pics of the finished product as it was getting dark. I also made a start on the second head by gasket matching the inlet ports and cleaning up the valve area.