The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: roadrocket on 07.03. 2019 20:31

Title: crank and cases - are they OK?
Post by: roadrocket on 07.03. 2019 20:31
Hello

I have been offered a crank and a set of cases. The crank should be large journal A 10 and the cases are stamped CA 10 RR 1475, which should be 1955 as far as I can gather. However I think the attached photo of the crank show very little distance from the sludge trap plug to the crank bearing, which makes me think it might be A 7?

The number on the cases seem very big, and not using the usual kind af letters (to my eye), also the area around the engine number looks as if it has been ground off?

I would be grateful for your input

Title: Re: crank and cases - are they OK?
Post by: trevinoz on 07.03. 2019 20:48
Otto, that appears to be the heavy RR crank.
No comment on the numbers.
Title: Re: crank and cases - are they OK?
Post by: chaterlea25 on 07.03. 2019 22:21
Hi Otto,
As Trevor says + only 650's went big bearing
VERY faked numbers  *eek* *eek*

John
Title: Re: crank and cases - are they OK?
Post by: berger on 07.03. 2019 22:44
I really don't think,- more like I know none of the rockets were stamped RR it was always CA10R -- DA10 R --- then CA10SR DA10SR and those numbers are away with the fairy's like hepolite piston rings--- that is unless you are very lucky-- like lucky lucky lenny and find some over 40yrs old in a BARN *whistle* *problem* *problem* *problem* *fight*
Title: Re: crank and cases - are they OK?
Post by: trevinoz on 07.03. 2019 23:20
Not correct, Berger.
All Road Rockets which came to Australia were stamped CA10RR.
Super Rockets here were CA10R & DA10R.
Title: Re: crank and cases - are they OK?
Post by: berger on 07.03. 2019 23:57
well I be corrected *conf2* , just like them yanks them aussies got to have two of everything *fight*
Title: Re: crank and cases - are they OK?
Post by: trevinoz on 08.03. 2019 01:25
So we should have two of everything.   *wink2*
If it wasn't given to us we would steal it, with our convict background.
Title: Re: crank and cases - are they OK?
Post by: RichardL on 08.03. 2019 01:28
I think the right chemistry or, maybe, xray would reveal the original numbers. Does anybody NOT see what appears to be the impression of a 3 between the two Rs? Then, maybe a 6 just before the 1 in 1475?

Richard L.
Title: Re: crank and cases - are they OK?
Post by: Servodyne on 08.03. 2019 08:29
Otto, that appears to be the heavy RR crank.

It looks like the post 1957 large journal 'standardised' crank with the removable flywheel.
Title: Re: crank and cases - are they OK?
Post by: roadrocket on 08.03. 2019 09:12
Thanks gentlemen, I am happy to hear that the crank look to be A 10 large journal. It should be ground to 0.20 and be non-oval as is (yes that would be round ...). The cases I will pass. I do not suspect the vendor of performing the trick stamping, but I don't want to ride around with dodgy stuff. The crank has a different source than the cases, so I'll proceed with that.
Title: Re: crank and cases - are they OK?
Post by: Swarfcut on 08.03. 2019 09:24
Otto... Cases look very suspect. The style and numbers are not quite right, so the cases are not what they appear.  OK if you need a set, but not right for a concours winning machine. Check they are a matched pair....identical numbers stamped side by side on the front faces,  but these too could be fake. A camshaft should turn easily by hand with no binding in a correctly matched pair, and as such is a quick test. I think you will do well to pass on them.

 The crank will be an A10, if it is big journal. Just check the big end journals still have some life left for a regrind.

 Swarfy.
Title: Re: crank and cases - are they OK?
Post by: BSA_54A10 on 08.03. 2019 12:19
Yes there are signs of the cases being ground and the numbers are not the correct font nor size.
However that does not mean there is anything suspect.

Funny thing about RR's is they were all owned by little old grandmars who only rode them to church on Sunday in second gear at no more that 1/4 throttle.
As such there is no chance that in the previous 60 years some ratbag would have ever run the snot out of the bike tossed a rod & destroyed a case is there.
That only ever happens with bog standard cooking version low compression A 7's dosen't it ?  ;)
Title: Re: crank and cases - are they OK?
Post by: trevinoz on 08.03. 2019 22:13
I stand corrected on my identification of the crank.
I didn't notice the radial bolt in the flywheel.
Time to clean the specs.
Title: Re: crank and cases - are they OK?
Post by: DuncanF on 09.03. 2019 18:20
There are still un-stamped cases around, but correct font stamps are very rare. It's not illegal to re-stamp cases, only to use cases you know to be stolen.

Even if they've been stolen, you are not breaking a UK law if they've been "recovered", i.e. if the bike or parts have been recovered and numbers removed from the police stolen property lists. The engine number may be anything you like, I know of a bike in Croydon where the engine number is "80LL0...", it's perfectly legal, and it's on the registration document. Mind you, it did take a while to convince Croydon police, when we got pulled over!

The last places I know where un-stamped cases were on the shelf, was Millers in Hastings, and Ken Chaters, in Bexley. Both now sadly closed, but cases do turn up at auto-jumbles.
Title: Re: crank and cases - are they OK?
Post by: hdawson on 10.03. 2019 06:37
Quote-- 'Mind you, it did take a while to convince Croydon police, when we got pulled over! '
Strewth!
The only time I have been pulled over by the highway patrol is to chat about the bike.
I offered to show my logbook but was told not to worry.
I think old bikes over here are more of an oddity and have many times seen police give me a wry look as if to say,
"What the hell is that thing?-on your way"
Too much trouble when there is so much low hanging fruit to fil the daily quota.
Sorry to digress *wave*

 
Title: Re: crank and cases - are they OK?
Post by: BSA_54A10 on 10.03. 2019 11:39
Ah yes,
I was using the WDB40 for work on day and after having done about 20 illegal things suddenly noticed the HWP on my tail.
Despite being "Me perfect" on went the blue lights and over Trevor went.
He then proceeded to tell me his father rode one of these during the war ( assumed to be WWII ) and he had always wanted to see one up close.
I never bothered to correct him, then rode away,,,,, very carefully.
Title: Re: crank and cases - are they OK?
Post by: worntorn on 10.03. 2019 15:34
When I built the Special and it was time for numbers I stamped some in that I liked.
When it was time for registration the search showed up a U-Haul trailer in Ontario with the same numbers.
The Motor Vehicles inspector hummed and hawed for awhile then declared " It's clearly not a U-Haul trailer so I guess we can register it"

Phew!!!

Glen