Author Topic: Broken case  (Read 705 times)

Offline RDfella

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Re: Broken case
« Reply #30 on: 05.02. 2020 18:00 »
BSA 54 – apologies if it seemed I was stepping on your toes, but I do get concerned that queries about nitriding BSA cranks keeps coming up, when that would not be a good choice. You did indeed state ‘not nitriding’ but I felt that using the term carbo-nitriding was possibly unfortunate as it could plant the ‘nitriding’ thought back into some peoples’ minds.
In that regard I was merely raising the fact tufftriding and nitriding are different, without going into all the details. Sure, the effects are very similar (fatigue resistance etc) but there are critical differences as you are aware. It’s bad enough that even some firms advertising such services don’t know what they’re talking about - I saw one stating that ‘nitriding, unlike tufftriding, is very shallow and if not careful could be polished out’! They went on to state that tufftriding causes less distortion. Best avoid that firm methinks.

'49 B31, '49 M21, '53 DOT, '58 Flash, '00 Firestorm, Weslake sprint bike.

Online BSA_54A10

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Re: Broken case
« Reply #31 on: 06.02. 2020 06:38 »
RD,
Never worry about challenging anything that I post.
We have now had some chit chat and hopefully enough too & fro to make it stick in peoples mints.
It was easy 20 years ago when you could just say Tuffride or tuffcoat & every one knew what you were reffering to but now days those prpritory names are fairly meaningless.
A member had his crank done decades ago & when doing a major rebuild was horrified when the grinder sent it back with full circumference deep cracks around all journals.
But the crank was running strong & true & he was running 10.5:1's
Bike Beesa
Trevor

Offline Superflash

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Re: Broken case
« Reply #32 on: 09.02. 2020 02:52 »
Hi all. I've cleaned up the new timing case and discovered something that doesn't make a whole lot of sense. I thought the plunger motors stopped being made in 1957. Yet I've found a date stamp saying 21.5.61....? Had a good look and it's definitely 61.
68 Trophy
74 Trident
74 XLCH Sportster x 2
86 Liberty Sportster
07 FXDWG (current)
53 BSA SF (WIP)

Online BritTwit

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Re: Broken case
« Reply #33 on: 09.02. 2020 04:04 »
What does the date stamp on the drive side say?  Should be close to the top of the chain adjuster

Offline Superflash

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Re: Broken case
« Reply #34 on: 09.02. 2020 05:11 »
22.5.52. Cheers
68 Trophy
74 Trident
74 XLCH Sportster x 2
86 Liberty Sportster
07 FXDWG (current)
53 BSA SF (WIP)

Offline Swarfcut

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Re: Broken case
« Reply #35 on: 09.02. 2020 08:47 »
   G'Day.
       It may have been part of a Service Exchange Unit. Page 37 of the 49-53 parts Catalogue has a note that a damaged crankcase half could be replaced with a new casting, and by all accounts factory matched to the existing used good half. But from experience, it is the timing side that usually survives, a rod through the drive side case being the usual malady.

     So that's a possibility, but halfway round the world hardly likely, however the stamp font used looks BSA factory style.  Maybe they just kept making spasmodic batches?

     Date on the Drive Side Case  is from a time of change and case may have the early crankshaft oil slinger or the later proper oilseal. The only difference is the size of the hole, early case can be opened up to take a seal.  If the drive side outer race is still in place, and no seal fitted, the slinger should be found still in place between race and case. I mentioned this difference in design with an earlier post.

 Cheers

 Swarfy.