I managed to get my crankcase breather off. It took some heat to convince it to budge. Probably the first time it has been touched in 66 years.
There was debris in there so it needed some attention.
I expected there to be a spring and ball bearing but find only a ball bearing with a threaded insert that holds in the bearing.
With the insert threaded down until it bottoms out there is still room for the ball bearing come off itâs seat when the piston is on the way down and pressurizing the crankcase. ball bearing seems to seal well in it's seat when I blow through it from the "outside".
So it does both suck and blow as I suppose it should.
Is that all there is to it ?
or is there a spring missing or any adjustment that I should know about?
Grant MacNeill, 1951 ES2 plunger,
Toronto
Attachments IMG_1534.JPG img_1535-jpgHi Grant, The drive side b…
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Hi Grant,
The drive side breather valve was fitted to the ES2 for most of it'sproduction life, and also the other singles. There is no spring in this so the ball bearing rises andfalls with crankcase pressure with the insert screwed in tight. The size of the valve is much too small to be of much use and at 60mph the ball is trying to rattle up and down 6 times every second ! A famous English tuner, Phil Kettle, told me the best thing to do was to remove the ball and threaded insert and forget them, or better still replace the original with a plain oil pipe fitting (1/4" BSP) with the largest bore available. On the other hand you may want to keep it to standard spec.
Regards, Richard.