A10 camshaft bush

[route 66]

Does anyone see anything strange about this primary side camshaft bush?

[Catz]

It looks like it's got a bit of scoring to the inner edge from the end cam.

[muskrat]

G'day router.
Do you mean it's not concentric to the c/case bore (kooks way out) ? It does seem odd but I've seen similar before.
Many years ago my job was to machine gearbox's. Sometimes the casting would sit a bit out in the jig so when bored the hole would look out of place but would be OK in relation to everything else.
Make a bar to fit in place of the cam and measure distance to the barrel face each end.
Cheers

[route 66]

I wondered about that but look to the bottom of the hole. The bush is even off centre to the innermost point.Here's a pic of another case I have.

[berger]

are the cases you have matching pairs , a number is stamped on the front of each case, if they are matching numbers put a cam in and see what happens

[muskrat]

G'day again.
Bergs got in first and what I was going to ask!
Possible if the cases aren't a matched pair.
Cheers

[route 66]

As matching as they can be.If you look right into the casing it's almost like the camshaft end has worn a dome like hole but the bushing is even off centre to that.I think a new bush has been fitted to a very elongated hole.

[muskrat]

G'day router.
You'll have to take it out. May have had an eccentric bush made.
Cheers

[route 66]

My thought is,if these bushes have been fitted then reamed through with the cases together,then perhaps the camshaft has been off parallel with the crankshaft.Now,all that would do is mean that the lobes of the camshaft on the primary side cylinder wouldn't have full contact with the followers and that cylinder would have more valve lift.Maybe these cases were replaced under warranty because of a misfire they couldn't cure.Who knows the history of all these secondhand parts? They're going back to where I got them,that's for sure.

[Swarfcut]

 The quick test is that the cam rotates freely with the cases bolted together. Like musky says we're not talking microns when considering these castings from 60 plus years ago. If that drive side bush has been replaced, more likely the timing side bushes set the datum and in fact everything is fine as regards parallel alignment with the crank.

 But confidence is another matter, and if you can get a refund all to the good, there are perfect cases out there somewhere. The numbers don't look as clear or as good a match as many, so treat with caution. Look for inspectors' stamps on the cylinder face, these are circular and bridge the crankcase joint. If present and complete, this confirms an original matched pair. Stamp a bit skewed? Odd cases with a bush offset to get a runner, crankcase number is artistic licence. Who knows?

 Swarfy.

[RDfella]

I wouldn't be overly concerned about that. The fact the machining for the bush isn't central to the casting isn't out of ordinary. In fact, neither case has the bush central to the casting lug.
Follow Berg's advice - if the cam rotates fine with the cases together, should be fine.

[JulianS]

Before spending money on that case, just incase the cam bush centre is off,  I would want to fit the cam with pinion plus the idler with pinion and the mag with pinion to make sure that the pinions mesh together properly and it all rotates freely.