Author Topic: UNIDENTIFIED DOUGLAS CRANK PARTS OFFERED.  (Read 4231 times)

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Offline LATDOUGNUT

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UNIDENTIFIED DOUGLAS CRANK PARTS OFFERED.
« on: 22 Jan 2012 at 12:20 »
Hi folks,

I have found among purchased e-bay stuff this incomplete crankshaft, believed to be from a Douglas. Please see the attached photo. Any offers please?

« Last Edit: 23 Jan 2012 at 17:38 by Dave »
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Offline David Lawrence

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Re: UNIDENTIFIED DOUGLAS CRANK PARTS OFFERED.
« Reply #1 on: 24 Jan 2012 at 15:19 »
Hi,
Regarding the photo of what is definitely a Douglas crankshaft, I would suggest that it is the rear end of a post war Mark or Dragonfly shaft (Clutch end) The taper should have a keyway. The only slight doubt is the centre web which appears slightly square edged in section, but this may just be the angle of the photo. It looks as though the crankpin has been partly pushed out of the centre web, if it has a step in the crankpin it would indicate that it was from a later type of crank fitted to the Dragonfly.
I will be interested to see who agrees or disagrees with me!
Dave

Offline eddie

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Re: UNIDENTIFIED DOUGLAS CRANK PARTS OFFERED.
« Reply #2 on: 24 Jan 2012 at 16:46 »
This crank is definitely not from a postwar Douglas and probably not even prewar either. Most prewar Douglas engines over 500cc and postwar engines had a 7/8" x 20 tpi thread. I don't remember any Douglas cranks having a coarse thread as shown in the photo. Also, most prewar cranks had the crankpins integral with the centre web. The only other possibility is that it could be from a Douglas industrial engine.
     Regards,
                  Eddie.

Offline David Lawrence

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Re: UNIDENTIFIED DOUGLAS CRANK PARTS OFFERED.
« Reply #3 on: 24 Jan 2012 at 21:52 »
Hi again,
As usual Eddie is spot on! no way is the thread correct for a Douglas shaft, and on closer inspection neither is the main bearing mounting like post war Douglas shafts. Also is that a bolt in the end of the crankpin?
Sorry for the mis information, in future engage brain fully before fingers on keyboard!
Dave