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Douglas 1913 Model P motorcycle

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Douglas 1915 3 Spd-Gearbox and Clutch

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Dave

2025-01-07, 19:16:39
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2024-06-08, 19:30:04
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Dave

2024-06-03, 09:23:05
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2024-06-02, 09:34:05
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Dave

2024-06-01, 19:33:27

Dave

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early veteran crank case oil valve

Started by steveale, 17 Mar 2016 at 04:51

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steveale

I searched and found prior threads where Doug provided drawings on the EW type oil valve.  On my 1913 the lower fitting has a straight bore below the cage with no taper seat for the spring to set...if a spring was inserted it would just fall into the crankcase oil passage.  The top fitting has a taper but it doesn't seem logical that the spring would be on top and pushing the disc downward.  When I dismantled mine, there was no spring inside.  Did the earlier veterans (mine is 1913) only have the disc sitting in the cage and it opened and closed with associated pressure/vacuum and no spring?  Perhaps the spring was added in following years to insure the valve was close at all time except for vacuum to draw oil? 

Any insights are appreciated....

Chris

Hi Steveale
The simple answer to your question is yes! I have come across one way valves with a full dia bore in the lower part of the body in veterans so that there is no way to hold a spring. They still seem to work.
Chris.

cardan


Simple flapper valves like this, using the weight of the flapper disc rather than a spring, are found on many veteran motorcycles - for example those used on JAP motors were essentially identical to the Douglas item. They were often found at the entry point to the crankcase, or on the outlet end of the drip-feed oil pump, or sometimes in both places.

If the disc is missing a piece of 0.005" brass shim (or a piece of aluminium Coke can when you've lost the original in the grass on the side of the road) cut out with scissors usually works fine.

Leon

steveale

Thanks guys the knowledge on this forum is AWESOME!  Leon, I'll have to remember the coke can as I cannonball across America.  Unfortunately with our litter problem there are plenty of them along the roadsides. 


One additional question...prior to my engine rebuild I had been using straight 30 weight oil.  After research I've decided to run a 20w-50.  Last night I filled the oil tank and was doing the pre-load pumps but noticed the oil was not running out of the sight glass as quickly as before.  The entire glass would fill up and take about a minute to empty into the engine.  Is the difference in oil weight causing this much delay or do I have a problem with my crank case valve?  I imagine it takes some time for the oil to seep through those slots on the sides of the valve disc.