By Jason Ballamy - Part five

Cylinder End Cover

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This is quite a simple piece after the cylinder. I used a stub end of cast iron bar but steel would do. Turn down to 30mm dia and then turn the 24mm dia x 3mm long spigot and part/saw off.

Now holding by the spigot face off to 3mm thick and decorate as desired, I went for a simple 20mm dia recess with a rounded edge. The original CME engine carried the CME logo here.

Now over to the mill to drill the six M2.5 clearance holes on a 30mm PCD and that’s the cover finished.


I turned down a piece of 1" bar to 24mm long enough for two eccentrics, parting cuts and a little to clean up afterwards then set the bar in the mill vice, indicate the middle then move 1mm to the back and drill and ream out to 10mm dia. It could also be done in the 4-jaw but I could not be bothered to change it over.

You can then part off two slices and finish to 6mm thick, drill and tap for a M3 grub screw in each.


I had intended to make this from 10mm PGMS (Precision Ground Mild Steel) which is what I have spec'd on the drawing but could not pick up any at the time I wanted it, and postage on one bit of metal would have been high, so I opted for some 10mm stainless steel which I already had, either would do the job.

The main shaft can be turned down to 112mm long which is right for the two Perseus flywheels that I used. If you buy different flywheel castings or want to add a pulley then you may need a longer length.

The pin can be faced off to give the required 22mm overall length then reduced at both ends to 8mm dia for a length of 6mm.

Machine up two pieces of mild steel 12x6x24mm and then, holding them in the vice, drill and ream the 10mm and 8mm holes. If you use a vice stop it saves having to locate the edge of the second web.
Clean up all the parts with solvent so the Loctite will make a good bond and then start assembly. I did it in two stages, first stick the pin into the webs using the shaft to keep things lined up. When that has set the pin/webs can be bonded to the main shaft, I supported them in a couple of V-blocks while things dried.
I'm more used to silver soldering crankshafts or cutting from solid so decided to pin the joints for good measure. Drill 1.5mm cross holes and lightly countersink.
Then push some 1.5mm steel rod through the holes and pein over the ends with a hammer.
All that remains is to cut out the middle of the shaft that is not needed and file the ends flush with the insides of the webs. The ends of the pins can be filed down at the same time.

Check that the crankshaft turns smoothly in the bearings and make any adjustments that may be needed as its easier to do it at this stage. Once happy that everything turns freely the base can be joined together. I used a small amount of JBWeld spread over the four joints and then screwed the parts together on a flat surface making sure that the crankshaft turned as the screws were nipped up.

If you leave the feet off it is easy to clean up across the whole end to remove excess filler and any high spots if the parts don't quite all lay flush. Once that is done the feet can be stuck in the same way. I prefer to use an easier-to-sand filler for cosmetic filling so some U-Pol car body filler was used to fill the screw holes. The same filler can be used to add a fillet around the feet and oiler bosses.

Part one here  Part two  Part three  Part four Part five  Part six  Part seven   Part eight