The sleeve drive sprocket has been drilled by Bob to allow for a vernier adjustment. The 9 holes allow the sprocket to be fitted to the timing shaft in a number of different positions.
With 22 teeth not being visible by 3, three mounting holes would allow the sprocket to be fitted three ways, each time a tooth ends up in a different relative position. To refine this further, three sets of three mounting holes have been drilled.
Why? Well during final assembly the valve timing will need to be set. This will be achieved by setting the piston at the point where a valve opens, moving the sleeve into the correct position and then bolting the sprocket to the timing shaft.
Sounds so easy when you say it!
While Dave works on the patterns, a little job I’ve been meaning to get around to I finally got around to! The Kawasaki brakes seize monthly during the British winters. Government sponsored rust fairies abound when they put salt on the roads. Might as well be riding through the sea!
The brake pistons are steel which is hard chromed. Ok for a while but the chrome is thin and eventually flakes off. New pistons are pricey and don’t last more than a couple of seasons. I knocked up a pair in 303 stainless steel, which should last a long time! (Longer than the rest of the bike looking at it).
So the front is rebuild and the rears will go in this afternoon. The mighty KLR 650 will be back up and running for winter – if I ever get to go anywhere 😷🥶🏍
Meet Dave. Dave swims like a fish, no, wait – that’s a 70’s government advice cartoon urging you to learn to swim.
Meet Dave, our new pattern maker. Dave cut his teeth making patterns for his apprenticeship, before branching out into wooden shoes. He’s fairly local and s biker too, so it all fits together nicely!
We’ve spent a few nights running through our project, the drawings and some patterns from other engines. Dave has suggested a few foundries to try around Leicestershire, so that’s next on the list.
It should take around 6 weeks give or take, so I could have a set of patterns in my hand for my Birthday. Or maybe, even, the castings!!
The drive pin showing off the lovely finish, the ball it fits and the sleeve in the background. (Albeit upside down). Just a case of removing it from the carrier and pressing it into the crank assembly.
Down to size and a very nice finish to boot. The cylindrical grinder did a good job on the sleeve drive pin, which now fits the ball on the sleeve a treat.Hardened steel grinds better and I will be making more use of this machine in future.
I hadn’t done much grinding before, but this has inspired me to get the 3-phase supply sorted for the Jones & Shipman 540 I have languishing in the garage.
Well not really. Much as this looks like a cool cocktail, it’s the sleeve drive pin being quenched. The whole jar became too hot to handle, so there was plenty of heat in the pin. Rock hard! Now to temper it.
When it had come to a reasonable temperature, we gave it a wipe and warmed it up again – this time to a dull red. From there into the oven at 200°C for an hour, before allowing to cool slowly.
Next up, it grinding to size on the cylindrical grinder.
Phase 1 of hardening the sleeve drive pin is to get it to a bright red heat. The butane blowtorch I tried wasn’t enough for the job, so I I bought a butane/propane mix. That was much better and with a few bricks around to reflect the heat it was soon glowing.
The photo looks like a space raygun about to vaporise something. Maybe I watch too much SciFi?
Next to quench it in oil.
Whilst I’m press hunting attention has turned to completing the sleeve drive. I haven’t bought any sprockets yet, but with an old one laid over the drawing along with some chain it began to get real.
Bob put the sprocket carrier / sleeve drive crank we made at the top and overlaid the oil pump and worm at the bottom. So the sleeve drive assembly looks pretty complete, certainly enough to see how it’s all going to work.
Some thought and effort has gone on in the background, working out how to set the valve timing. Then how to adjust the valve timing after that! Using 22/44 toothed sprockets and 3 fixing bolts, we’ll have a vernier adjustment to fine tune jumping a tooth.
Bob has devised a 9 hole mounting pattern that allows timing adjustment down to 0.9°. That should do it!
High hopes this morning when a friend set me up with access to a 30 Tonne press. There’s a lot of weight in the flywheel assembly now but I duly carried it to the car and set off for Rugby.
Matt and his mate Andy were great, giving me a quick operation lesson and leaving me to it. I prefer that than someone taking over, though they were on hand to help and advise.
One half of the crank pin is now fully home, but the other side still has about 10mm to go. So its off to find an even bigger press to finish the job. Everything appears to be straight and parallel, so fingers crossed that next time it’ll all go in.
Despite getting the timing side flywheel up to 240, and the crank pin down to minus 15, the trusty rusty press just wasn’t enough even at 17 tonnes to push it fully home.
We’re gonna need a bigger press!
A valiant effort and we’re within an 8th of an inch, but the call has gone out to mates with heavier duty kit.