Author Topic: Large journal crank  (Read 1579 times)

Offline Rich

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Large journal crank
« on: 02.03. 2012 19:05 »
Hi all
I have just aquired a large journal A10 crankshaft already reground and with a new main bearing fitted, however on inspection I notice that the sludge tube has only one plug threaded into one side only, the other end being solid , in other words the tube is in a blind hole.
Is this normal? as the large journal crank I have had for some time awaiting ready cash to have reground has two sludge trap plugs,
As I can now start putting together a spare engine for my S/R I need to know which crank is correct.
Many thanks
Richard

Offline Rich

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Re: Large journal crank
« Reply #1 on: 02.03. 2012 20:33 »
I have just had another look at the crank in question, its remarkable what one misses in the excitment of getting a bargain, the crank must be an alternator model as it has a longer drive shaft with a keyway in it, it may be an A65 crank or are they the same as an A10 altenator crank?.
Anyway I have two choices to give it back and get my money back, no problem there, or offer it for sale cheap and let some one else have a bargain getting the correct crank, as if one prices up the cost of a regrind then the cost of this at say £125  is cheap. I believe it is 010" undersize.
I have until tomorrow to decide. if you can throw more positive info on this then please do
ta

Online chaterlea25

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Re: Large journal crank
« Reply #2 on: 02.03. 2012 23:19 »
Hi Rich,
The A65 timing side bearing is bigger than the A10's at 1.5in. ??? A 10, 1.375in? (or is it the other way round????)
There was a thread on this subject a few days ago

HTH
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Re: Large journal crank
« Reply #3 on: 03.03. 2012 07:07 »
sounds like time to do some measuring and look for identifying features. The A65 crank has a much shorter stoke.
A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
New Zealand

Offline Rich

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Re: Large journal crank
« Reply #4 on: 03.03. 2012 08:21 »
Stroke even,
Looks the same as the A10 except for the shaft, I have another large journal spare on the bench, the throw looks the same, however one has a slightly larger timing side journal, but that may be due to the fact that one has been reground, I will find out the standard and undersize measurements and check later, just off to Shepton Mallett auto Jumble in Half an Hour

Offline LJ.

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Re: Large journal crank
« Reply #5 on: 03.03. 2012 09:03 »
Isn't there any part numbers stamped anywhere? indeed crankshafts and their sludge traps were discussed a few days ago and I had to go out and examine what I have, I found part numbers and wondered there and then why the part numbers were not mentioned in the discussion.
Ride Safely Lads! LJ.
**********************
1940 BSA M20 500cc Girder/Rigid- (SOLD)
1947 BSA M21 600cc Girder/Rigid-Green
1949 BSA A7   500cc Girder/Plunger Star Twin-(SOLD)
1953 BSA B33  500cc Teles/Plunger-Maroon
1961 BSA A10  650cc Golden Flash-Blue
1961 BSA A10  650cc Golden Flash-Red

Offline Rich

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Re: Large journal crank
« Reply #6 on: 03.03. 2012 15:00 »
it is an A65 crank 010" undersize reground crank.
I will now sell it on cheaply I may even make £10 or £20 on it and it will still be a cheap crank for someone, all that will be needed is a timing side bush to be made and new big end shells and it is ready to be used.
If anyone knows anyone intersted then pm me
Thanks as usual
Richard