Author Topic: Is this Douglas?  (Read 4643 times)

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Offline sarolea

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Is this Douglas?
« on: 18 Jan 2010 at 11:57 »
Hi,

I've had this lying around for a while.
Now that i'm cleaning up the shed a little I started wondering what it is exactly.

Could it be Douglas, and if so anybody knows which year/model?
I turned it over to see if i could spot a serial number somewhere, but at first glance i saw none.





« Last Edit: 18 Jan 2010 at 20:23 by Dave »

Offline Chris

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Re: Is this Douglas?
« Reply #1 on: 18 Jan 2010 at 17:01 »
Hi Sarolea
    This is a douglas engine with the Douglas flywheel clutch (albeit with all its innards missing), It is either a late model EW 350 or a subsequent model which used a virtually identical engine except having separate cylinder heads. I.m not quite sure when the separate heads became available. The early EW models of 1926 and 1927 had cylinder heads integral with the barrels.  Chris.

Offline sarolea

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Re: Is this Douglas?
« Reply #2 on: 18 Jan 2010 at 18:19 »
Hi Chris,
thanks for your reply.
The idea of an EW crossed my mind too. But, and I am by no means a Douglas expert so correct me if needed, i assumed they were all sidevalves.

And what i have seems to be the leftovers from an OHV engine, no?

Offline Chris

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Re: Is this Douglas?
« Reply #3 on: 18 Jan 2010 at 18:45 »
Hi again
   On reflection I think you are correct I had missed the fact that there is no boss for tappet covers to be fitted between the crankcase and the cylinder heads. In that case it is probably the D28 or D29. Which are the 350cc overhead valve models of 1928 and 1929. Quite a rare model as there are only seven listed in the LDMCC Machine Register. Sadly a lot of parts missing. Chris.

Offline Doug

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Re: Is this Douglas?
« Reply #4 on: 19 Jan 2010 at 03:35 »
Sarolea,

The flat bottom to the timing cover places it as 1930 or later; as does the just visible rotary breather valve on the crankshaft. The 1930 350cc models were mounted on a oil sump. As I do not see the required hole in the bottom of the timing chest for the oil pump drive shaft, the minimum date now moves up to the 1931 dry sump model, the A31. The A31 also lacked the bosses inside the timing chest (as does your engine) for the exhaust valve lifter mechanism. I am not sure just when, but these were reinstated on later engines. Possibly by 1934, certainly by 1935. Given there were likely no 1933 350cc machines manufactured (financial distress), that narrows the possibilities down to 1931-32, and a A31 or A32 model. The OHV lightweight based on the 350cc side-valve machines (K32 & M32) had a rounded shape to the top of the timing chest.

I do not know of any means to distinguish if it is a 1931 or '32 and I believe the model remained unchanged. This is reinforced by the fact the engine, frame, and gearbox prefix codes as assigned by the factory remained unchanged. (Exception, very late '32 may have received a new style plate cylinder heads, but your barrels are not for that type.) The engine prefix should be EV and will be stamped on the top of the crankcase. If you scrub the area indicated below you should find a trace of it followed by a three or possibly four digit number.



-Doug

Offline sarolea

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Re: Is this Douglas?
« Reply #5 on: 19 Jan 2010 at 18:06 »
Thanks Doug,

I think you're correct since a little cleaning on the indicated place revealed a number: EV 18xx
So these are the remains of either an A31 or A32 engine.

If anybody on the board here is on the lookout for these parts (cranckshaft and pistons are there, and turn over) they can contact me. As I, unfortunately, do not have any other parts from an OHV Douglas...

Offline bas

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Re: Is this Douglas?
« Reply #6 on: 19 Jan 2010 at 21:05 »

Hello Doug!

Do you think I can use this barrels and cranckshaft in my D28 engine?

Or do you know somebody else who had parts to complete my engine?

Thanks a lot in advance,

Best regards, Bas from Holland

Offline Doug

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Re: Is this Douglas?
« Reply #7 on: 20 Jan 2010 at 04:31 »
Bas,

The cylinders for the A31 would not be the same at that for a D28/29. Nor are the crankshafts for the 350 OHV and side valve the same. The side valve cranks were drilled out on the drive main shaft to save weight, but this was not done on the more powerful OHV engines as it weakens the shaft. But more importantly, the D28 is similar to the EW in that it feeds oil through the crankshaft to oil the connecting rods. The A31/32 crankshaft is not drilled for oil, as the oil is feed to the crankshaft externally via a spray bar.

-Doug

 

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