[I've cross posted this from another forum so theres a bit of extra story to go with the build]
The main idea is to use a car engine again but this time use the Peugeot / Citroen Metro etc 1500cc diesel engine and gear box that has been fitted to many cars over the years rather than the larger 1900 lumps. Then use the car gearbox but get the drive from the second shaft in the box rather than from the diff output like other builds. What makes this possible is that all cars of this era started off mainly as 4 speed boxes and then as sales pressures went up they all competed by offering 5 speed options. So rather than design a whole new gearboxes they were adapted, ie the 5th gear was put outside the original gearbox on extended shafts and then enclosed with a tin cover. This will allow a hole to be made on this simple cover and a shaft attached to the gear to go to the shaft drive of the bike. Hopefully this will be more clear as the build continues.....
The first thing to do was to obtain a left handed shaft drive. The reasons for using a shaft on the left is the direction of shaft spin on the output of the gearbox I plan to use. I was going to use a BMW R80 shaft drive unit upside down but after extensive research found that the crown and pinion gear in the bevel drive could easily have been either a spiral gear or a hypoid gear. There is no real way of knowing which but if they are hypoid then because of the tooth profile are weaker in reverse than forwards. Odd but thats what the text books are saying.
Anyway on the Way to collect the complete rolling chassis there is a massive rumble and I pull over onto the hard shoulder to find the alternator lay shaft bearing has collapsed. To get me going I pull the belt to one side and proceed at about 45mph for about 5 miles until I find a bit of shelter off the motorway.
Loads of shelter and almost out of view from the passing punters where a spare bearing is fitted.
As my legendary lateness was preceding me Matt had prewritten a note for me and was indeed just getting into his car to go to the airport as I arrived. He left a friend of his to oversee the removal of the rolling chassis. Infact they got so fed up waiting for me that they had already dismantled the whole bike leaving me the only task of loading it up and sodding off which was all rather swift.
I do admire his garden burner.
The trip home was very slow, there was a mild head wind which required full throttle which anybody who has followed the Z482 diesel bike know results in epic smoke from the exhaust. Many stops were had to check the straps and have a cupper.
Also note: The Z482 has done 11000 miles since I built it in the spring.
The next mammoth task was to clear the bike room of the house and took the best part of a whole day but well worth the effort.
First lay out the shaft and have a think over a cupper.
Then I located an engine on Gum Tree from a local bloke. It took 4 days for him to return my texts and messages but I eventually obtain an engine and gearbox for £180 after knocking him down by £50 and then getting him to transport it across town and help me up the garden path with it.
Engine on the floor next to the rear end.
There is a whole bunch of useless bits here.
A vaccum pump that can be removed and blanked off later on.
Then there is this monstrosity under the vaccum pump that holds the fuel filter and a whole load of plumbing bollocks and the thermostat.
All that can be removed and a adaptor plate made to hold only these two tiny bits for the thermostat and radiator connection.
Much better
But the inlet manifold also comes off because I dont like it.
Engine stripped of useless bits and looking more compact already.
Then it's gearbox off time
Then the tin end cover removed to expose the 5th gear.
The nut is removed after jamming a bit of rag in between the gears to lock them solid.
This allows removal of the three pronged washer thing that appears to be retaining the synchro unit.
So somehow I've got to attach a shaft to this hardened centre bit of the 5th gear synchro unit. It is solidly attached to the output shaft of the gear clusters but without the annoying reduction to the differential unit.
This shaft is obviously offset to the input shaft and hence offset to the centre of the engine. A rough measurement of 60mm offset is made.
But the offset of the chosen swingarm is about 90mm So if I want to mount the engine vertically it will be 30mm to the left. I shall think about this problem later.... maybe tilt the engine slightly to keep the centre of gravity in the centre of the bike.
The gearbox in position next to the shaft. To get the drive on the correct side of the bike I've had to invert the gearbox. I shall have to make an adaptor plate to hold it in this position on the engine. As well as make new filler / drain plugs and block the breather and replace the selector arm seals which might be a strip and rebuild job. I may also have to relocate the starter motor and chop chunks off the diff part of the gearbox housing which I hadn't anticipated.
The adaptor has to couple the shaft to the 5th gear synchro bits.
Because of the extra length of the gearbox and the longer swingarm of the GS650 I estimate the whole finished bike will be about 450mm (or about a foot and a half) longer than a normal big bike which will be interesting.
Anybody know if the GS650GS had a oil flooded transmission tube like the BMW R80 or was it dry with greased UJ??
.
). Crownwheel is *outside* the pinion on Russian FD units.
