Bush - Main bearing to Primary chain drive

[stagowner]

I need a Bush turning that spaces the primary chain drive cog away from the Main bearing.

unfortunatly my little lathe wont handle anything above 1" dia

Can anyone point me out some one who would make one for me at reasonable cost,

Phosphor Bronze -

1.317" OD
0.981" ID
0.4" long

Thanks

[richie1958]

Why phosphor bronze Stagowner? Is it a spacer, or does it act as a bearing?
                                                                                                      Richie

[stagowner]

Good Question, It looks to me that it should be a tight fit into the engine casing (to prevent oil from pouring out, and the crank shaft has to rotate inside it. The engine I’ve stripped had one but it’s made of steel and badly worn, plus its only ½ width of what I require for some reason and it looks like it’s got hot at some point as it’s blue in color.

The casing I’m using now the bore in the aluminum is slightly bigger than standard, again I can only put this down to the steel spacer rotating, and in combination with a worn main bearing the result is its worn the casing a bit.

My only course I Think is to have one made

[MilitaryRon]

What engine is this Stagowner? I'm with Richie on this, wondering why there should be a bronze bush. Ron

[richie1958]

OK Stagowner; I've just pulled the spacer you're on about from my C11G cases. It's not supposed to be a press fit in the left hand crank case. On my bottom half it is a sliding fit in the case, but fits through and seals on a lip seal. The inner half that runs in the crank case has six holes drilled radially, presumably to distribute oil to the crank case/spacer interface. There is a funny little key on the inside that locates on one of the crank shaft splines. The spacer appears to be made of hardened steel, and although the ID and OD roughly coinside with your dimensions - ID 0.985"  OD 1.308" The length is 0.938"
By the fact that it's got a key on the inside, it's obviously supposed to rotate with the crank shaft. Although mine hasn't got so hot that it's turned blue, there is some wear around the point where it runs in the crank case. This has to be caused by a knackered main bearing at some stage in the engine's life. If all is healthy in that department, the spacer should just whizz round on a film of oil.
                                                                                            Richie

[timsdad]

I, too, have been a bit puzzled by this, Mr Stagowner. I'll have a look at my own lump when I'm passing, but if all on that side is held together by the primary drive sprocket nut on the end, then everything is turning more or less together at engine speed. Most of the oil is held in by the gasket between the primary case and the crank cases, splash through the bearing is kept in by the seal round the steel spacer in question and the remainder comes out of the breather onto your boot. I think your spacer should be a nice, sliding fit in whatever is wrapped round it. In the case of my bike, it was a very hardened felt-type seal but Richie's alternator arrangement might be different to my dynamo model. I would think perhaps a knackered main bearing has caused your particular problem. Cheers, Ray

[stagowner]

It’s a 1938 C10 casing, on the C10 –there is a steel washer that’s fits into the casing before the main bearing goes in. but this won’t seal any oil. There is also no keyway, so I was guessing that the bush is stationary and the main shaft rotates in it – hence bronze.

So to clarify the bush fits onto the main shaft and then rotates against the aluminum housing? Hmmm no wonder it’s worn and leaking oil.
The other engine I have striped has no seals, and that engine used to pour oil into the chain case, so I was intending getting this right on the rebuild

I would like to pursue the manufacture of a press fit Phos Bronze bush

[richie1958]

The spacer I'm referring to Stagowner just slides into the crank case, through the oil seal and butts up against the nearside of the main bearing's centre journal. Presumably the engine sprocket butts up against the outboard side of the spacer. If it was a press fit in the crank case, because it is sandwiched between the main bearing journal and the engine sprocket, regardless of whether it is keyed to the main shaft or not, the crank wouldn't go round!

[MilitaryRon]

I have been looking at my 39 parts list. (is this the same as 38?)  The bush stated is 65-2052 It,s top hat shape with what looks like an oil grove round the outside. For the life of me I can't remember what the bush was like on my 39 C10 but my photos do show it as a brass colour. Although I took a comprehensive photographic record of my rebuild...the one you want is not there. I can post the pictures I have if you want them. Meanwhile here is a picture from the parts list. It also shows the shielded drive side bearing 24-732. Not a bad idea to fit a modern sealed bearing with one side of the seal removed.  Ron

[richie1958]

Although my later one doesn't have the top hat brim, and it's got six radial holes instead of the oil groove, the one in the above spares book is a whole lot longer than 0.400". I'd guess it's about the same as my later one ie 0.938"
I'm guessing your primary chain alignment relies on the length of this spacer being correct.
         Richie

[richie1958]

Where's Owen when you want him    Probably swanning around in the hallowed halls of academe 

[timsdad]

My name's not Owen but perhaps I can help as I nailed my 1940 C12 bottom end together last week.

The top-hat bush you mentioned, Ron, is the timing side main bearing bush. On the drive side, there's the oil retainer washer tucked into the N/S case under the main bearing and all held in with a spring clip in a groove in the case. On the outside of the L/H casing, there's a cylindrical hardened steel bush that slides onto the drive side crank shaft up to the main bearing, followed by the sprocket and cush drive assembly. This bush, according to my 1940 parts tome, is called an Engine Shaft Distance Collar, part no. 65-2048. Mine measures thirteen sixteenths long, an inch and five sixteenths O/D and 25mm I/D. I know the inside diameter is in new money but the main bearing, like the piston, is metric, it's not my blacksmith's measuring! The inside diameter of the C10 bush may possibly be smaller because the 350 has a beefier bottom end but they're the same part number according to my parts book and they look to be about the same size as you quoted for your new bush.

My distance collar is unworn and only a bit shiny on the quarter inch where it spins against the crank case hole. There's no seal as such on my crankshaft, I presume it relies on the oil retainer and the previously mentioned gaskets. I've fitted a sealed main bearing, with the plastic seal removed from the flywheel side, to help keep the slippery stuff in.

I think you just need a new, steel bush, Mr S, and as long as your main bearing is OK then all will be fine. All the best, Ray

[MilitaryRon]

Yep! My mistake. These bloody pre war parts lists are a sod to follow! As you say Ray it's just a steel collar. Which must surely go round with the shaft. We could use Pete Allen (WDC10's) here. I think he has some factory service sheets for this period. I wouldn't mind a copy Pete if it's possible.  Cheers Ron

[timsdad]

Yes Ron, it's a nice, sliding fit on the crankshaft but is held tight by the sprocket and cush drive.
My parts book is also a bit tricky, I think it's a photocopy of a re-copied, not-very-good photocopy! The small parts and some part numbers are not too clear but the larger stuff help me to see what my missing bits should look like. Also helped by the photos of your muddy coloured bikes! Cheers, Ray

[camman3]

My parts list for C10L, C11, & C12 call it an engine breather collar (hence the radial holes) but it is listed as part no. 29-2027.
It is clamped up by sprocket and rotates in oil seal part no. 29-1970.
Also listed, are spacer washers 66-1705 or 25-389, which are used to for sprocket alignment. Like Ray said it is hardened and ground steel, and only spins in oil seal.
I will post pictures later, if they help?
Graham