Engine page 4
Cylinder head fitting
The head is fitted and the four bolts that also retain the rocker gear are torqued to 3.0-3.5 m/kg. The valve rocker clearance should be set to 0.2 mm for the exhaust valve and 0.15 mm for the inlet valve. After the initial running in period these settings should be checked and if necessary adjusted again.
Valve timing
This is a picture of the degree disk that I made. It's a simple plastic protractor attached to a metal base plate. I made this to check the valve timing. It's actually not essential, you set the valve timing when you install the chain. I did this just for fun.
Generator body
This is the generator body. It houses the field coils, regulator, condenser, points and ignition coil. I reconditioned the generator myself because exchange units are very expensive to buy. The original bosch electro-mechanical regulator is not visible. It had been replaced with an external unit sometime in the past. I don't believe that the generator was functioning correctly, as the previous owner had to constantly charge the battery with an auxiliary battery charger.
Generator field coils
This is looking into the back of the generator. Those four discs are the field coils. They are coated with Shellac, a resin like substance used in the 40s and 50s to insulate electrical components. You can see on the bottom field coil that the shellac has become brittle and flaked away. There are a few simple tests that can be done with an amp meter and charged battery to test each coil for operation.
Generator re chromed
The generator body had become rusty. I pulled all the components out and had the body chrome plated. The generator body was originally zinc plated, they were never chromed. I decided on chrome because it looks quite good and is weather resistant. Here you can see that I have fitted an electronic regulator. The advantage of the electronic regulator is that there are no mechanical contacts to become dirty and foul. It's also a direct replacement to the original regulator and is cheaper than the original bosch type, which is still available.
Feild Coils
I tested the field coils and they seemed to function quite O.K. When re fitting, care must be taken when replacing the coils and the pole shoes that they are in exactly the same position. The rotor spins very close to the pole shoe so any misalignment will cause metal to metal contact. Which we don't want.
Static Timing
Once everything is back together the static ignition timing can be set. I did this by putting the "S" mark of the fly wheel in line with the notch on the crank case, and then turning the points base plate left and right to find the position at which the points just open. I used a simple multi meter to check when the points open and close. You can also use a light or buzz box, in fact anything that will indicate the opening and closing of an electrical circuit. The R25/3 static timing is set to 7deg BTDC.