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BSA C15
BSA C15
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C15 pre-65 Engine |
I decided to strip down the engine and rebuild it because while I was cleaning down the exterior engine case I
noticed that the joints had been made using 'Silicon Rubber' and not proper jointing compounds. The engine was running, but I would rather be
'safe than sorry'.
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| Primary Drive Side
I started by removing the Primary Drive casing and exposing the Alternator & Clutch' and it was then apparent that I had made the right decision. The stator was then removed and requires new feed wires soldering in place. Next the clutch was opened up and the innards confirmed that I had done the right thing as the cush drive was ceased. The rotor was pulled using a three leg puller and the clutch housing using the correct tool. This then allowed the inner cover which is held by 6 screws to be removed. This is the best time to remove the final drive chain sprocket. You will not be able to remove the gear train later on otherwise. Click on the photo's for a better view |
| Cylinder Barrel, head and piston.
The Cylinder was next to get attention. Having removed the rocker cover nuts, or at least those that were there, as one of the studs was missing due to a stripped thread which will need a heli-coil. The rocker cover was lifted and the pushrods removed. The cylinder head is retained by 4 nuts, and these were removed to expose 4 copper washers, which are not standard and definitely not recommended. The cylinder was lifted, having first checked the bore for wear, of which there is none apparent. The pushrod tube was now removed and requires some plating. Having exposed the piston I wrote a letter 'F' on the front with a marker pen. Do Not Scratch marks on it. The circlip for the gudgeon pin was removed by pushing a .006 feeler under it and then edging it out with a screw driver. The piston was then warmed using a cloth placed in boiling water and the gudgeon pin was slipped out. The parts were then placed in a small box to protect them. The damage to the barrel was not caused by me, but I will repair it before the rebuild. Click on the photo's for a better view |
| Timing Side
The timing side cover was removed having taken out the retaining screws and the distributor clam screw. The odds are this cover has already been off once as it had to be removed to remove the clutch cable, but on later models a rubber cover was fitted to eliminate this. The distributor can now be removed from the engine with a twist and pull, it is that easy. With the removal of the outer cover you will expose the clutch actuating arm and the kickstart spring. Examination revealed that the clutch pushrod and the cup on the clutch actuating arm are damaged and will need repair or replacement. The gearchange camplate cover was removed which also brought to light the fact that the threads were none existent, another job for later. The split pin retaining the camplate spindle was removed and then the spindle was eased out. Click on the photo's for a better view |
| Gearbox
The inner timing cover is next to come off. Remove the nut from the camshaft first and then the inner cover which is retained by 7 screws and as it is slid away the gearbox becomes visible. If you forgot to empty the gearbox oil, you will now see it deposited over the workbench. At this point it is worth noting the timing marks before your enthusiasm gets the better of you. The gear cluster can now be slid out and careful examination be made before wrapping it up in a clean lint free cloth. Click on the photo's for a better view |
| Camshaft
This can now be removed and examined. Pitting of the cam lobs is unusual, but indicated that the engine has stood idle for a prolonged period of time. Unfortunately this requires replacement, as the case hardening is not deep and it will only breakup and deposit metal into the oil causing other damage later. Not a cheap part either. You will also see the cam followers which are in good condition here. Click on the photo's for a better view |
| Oil Pump
The sump plate is retained by 4 nuts and once this is removed you can extract the three screws holding the oil pump in place and remove this item. Check the oil deposits in the sump as this may give clues to the condition of the engine. Click on the photo's for a better view |
| Crankshaft & cases
Now remove the nut retaining the camshaft drive from the crank using a two leg puller. Before removal of the distributor drive spline can be accomplished you will have to remove the key from the shaft. The spline gear will then slide off into your hand. You can now remove the bolts and nuts holding the two halves of the crankcase together and separate these. Do not force anything between the cases. The crank is now exposed and can be pressed out of the main bearing. Below you can see the 'Silicon Sealant' that was used as the gasket. Not the product for the job. This would result in a lovely oil spill onto the garage floor and could have blocked oil ways if it had broken loose. At this point I removed the cylinder head studs which will be cleaned up and possibly plated. The journals can now be examined and also the big-end for play. Fortunately despite the camshaft corrosion, the bearing surfaces are fine, as are the bearing tolerances and the gearbox internals. Do not forget to clean out the sludge trap before you start re-assembly. Click on the photo's for a better view |
| How to Remove the Sludge Trap Plug by Brian Pollitt.
Be warned, when you have the crank out of the engine, always clean out the sludge trap. If you can't get them out, then remove all the burrs and dot punch marks at the side carefully by drilling just deep enough on each one to remove the burring. Then find a large Allen key and a drill just a little larger in diameter than the across the flats measurement of the Allen key and drill the centre of the sludge trap plug. Now, drive in the Allen key until it goes right in to the plug then trap it in a vice and turn the crank to screw out the sludge trap plug. Buy a set of Allen key type sludge trap plugs from SRM and never have the trouble again. Thanks to Brian Pollitt, BSA Owners Club for the article on 'How to Remove the Sludge Trap Plug' |
