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Re: Constellation - breather bolt

Posted: Thu Aug 11, 2022 8:43 pm
by Adrian

Re: Constellation - breather bolt

Posted: Fri Aug 12, 2022 6:32 am
by Jakub
Adrian wrote:
Thu Aug 11, 2022 8:43 pm
Is THIS the stuff?

https://www.ebay.co.uk/itm/223789673562 ... SwtC1d3U~d

A.

Yup. Looks like the one. However the price seems exorbitant.

Re: Constellation - breather bolt

Posted: Fri Aug 12, 2022 1:13 pm
by Cape Blue
That's very decent of you, I appreciate it.

How do I give you my address details privately - can't see a function to do that?

Re: Constellation - breather bolt

Posted: Fri Aug 12, 2022 1:31 pm
by Cape Blue
Cape Blue wrote:
Fri Aug 12, 2022 1:13 pm
That's very decent of you, I appreciate it.

How do I give you my address details privately - can't see a function to do that?
Found your email - emailed you.

Re: Constellation - breather bolt

Posted: Mon Aug 15, 2022 9:17 am
by Jakub
Short remainder, the 1959 model has just atmospheric outlet on the left side of the crankcase, just below the cylinder. The 1960 model has outlet in the same place but with two ring/plates operating as one way valve and the small diameter pipe connected back to the oil tank, additionally there is breather in the crankshaft nut connected to the chaincase.

I do have 1959 bike but with 1960 setup.

I did experience increase in overpressure in the chaincase manifesting with lots of oil coming out from the chaincase breather hose.

So I followed advice from certain Constellation owner and blocked off the breather nut. Wrong advice. Don’t do it.
I am old but did a rookie mistake. Mixed two different solutions from different years. Closing off the breather nut perhaps works well with atmospheric outlet. Not with these two tiny valve plates. As a result I have now oil weeping from under cylinders. Suspect crankcase pressure damaged the paper seals.

And with hindsight I suspect original reason for overpressure was one of the plates in the side breather got skewed and didn’t work properly. With engine working amount of overpressure from the side pipe was negligible compared to same setup but with plates removed.

Re: Constellation - breather bolt

Posted: Mon Aug 15, 2022 4:45 pm
by Vince2
Hi, does your oil tank cap have a hole in it? Vince

Re: Constellation - breather bolt

Posted: Mon Aug 15, 2022 5:44 pm
by Rasp
I was very surprised when I recently stripped my Constellation (1960). I found that there were holes, around 10mm diameter, (definitely from the factory) that directly connected both the crank and the timing case with the oil tank. Because of these holes I couldn't see the point of breathing gas though a one way valve from the base of the barrel into the oil tank when there's a hole leading leading back into the crankcase. I have plugged the hole in the top of the oil tank and directed the breather onto the chain.
Rasp

Re: Constellation - breather bolt

Posted: Mon Aug 15, 2022 7:55 pm
by Vince2
Hi, dont block up the oil tank, it needs to be vented, bear in mind the return pump is double the capacity of the feed , you dont want a pressurized oil tank. Vince

Re: Constellation - breather bolt

Posted: Mon Aug 15, 2022 9:55 pm
by Rasp
I've only stopped the one way breather below the left hand barrel breathing into the oiltank. As I said in my last post there are internal holes connecting the crank area with the oil tank and the so the one way valve will reduce the pressure in the crank area, the timing case and the oil tank if it vents to the atmosphere.
Rasp

Re: Constellation - breather bolt

Posted: Mon Aug 15, 2022 10:00 pm
by Rasp
Jakub, thanks for the tip about the EPDM foam rubber seal. I ordered 7mm diameter, easy to fit and a perfect seal.
Rasp