FT: Frame (Twin) Elephant trunk breather
- Thread starter Vincent Brake
- Start date
I changed my mind, Put it on my Ex L/ning rep', Very neat , Very pleased. Cheers Bill.
Hello youngjohn.. I'd be interested in one of your breathers also... I have rigged up a PCV onto a D cap on the rear cylinder spring cap (highest point I could use) I've used a PCV that I had left over from my Harley (big motor) drag racing days. We would run the PCV anywhere where it was practical, never really thought about it being vertical (it seemed to work though) I've mounted the PCV under the battery, horizontally... (now I think of it, BMW twins mount their breather vertically) I've tried to mount my valve in a practical and unobtrusive way... but now I'm respecting your idea that I could do better, I'm almost saying I've got it all wrong, but I hope I'm just overthinking it (that happens a lot with us Vincent owners) I would prefer your idea if you have a 'kit' you could send me... I'm in Victoria' Canada... Oh and Nigel, I've read your comments and agree, I did study those theories also but I have had good experience with PCVs so I'm on that road for now. Thanks John
Good evening,
thanks for the picture! Two questions:
1) does it make a difference whether you use the inlet or outlet valve
cap of the front cylinder for the breather?
2) Is there an internet shop where I can buy the plack plastic part which provides the 90 Degree
angle? I bought one made of brass, would prefer black plastic.
Best regards
Dirk
thanks for the picture! Two questions:
1) does it make a difference whether you use the inlet or outlet valve
cap of the front cylinder for the breather?
2) Is there an internet shop where I can buy the plack plastic part which provides the 90 Degree
angle? I bought one made of brass, would prefer black plastic.
Best regards
Dirk
Hello
Could you add me to your list for when you make a new batch (I've already got a new 'D' breather cap if one is needed)?
Thanks
Duncan (Scottish Section)
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Hello, hopefully attached photos of a new reed valve breather set up for my two engine's. The one with a stainless out let pipe is based on an Ivan Caffery unit which work well but was noisy due to the plastic ball used.
This has a oil separator that connects to a D valve cap on the front exhaust valve spring. Not sure this is needed as no oil comes out of the other one and it only has a 16mm silicon pipe to atmosphere.
The reed valve is from eBay, easy to find, and needs milling down to make it shallower. John.
This has a oil separator that connects to a D valve cap on the front exhaust valve spring. Not sure this is needed as no oil comes out of the other one and it only has a 16mm silicon pipe to atmosphere.
The reed valve is from eBay, easy to find, and needs milling down to make it shallower. John.
Attachments
My brother had this elephant breather as can be seen in the last picture on his B twin.
He fitted the device from a start after a nut and bolt restoration before ever trying if it was necessary.
The breather worked very well, but what a noise!
On tick over the breather made more noise than the engine, also when trundling along it made a noise that could still be heard above all the engine noise.
As good as it was, I would try every thing else possible before fitting this banister to my bike.
Simply because of esthetic reasons as well as the noise.
Maybe I am old fashioned, but there must be better ways to do it without spoiling the looks of the most beautiful motorcycle engine ever made.
Bernd
He fitted the device from a start after a nut and bolt restoration before ever trying if it was necessary.
The breather worked very well, but what a noise!
On tick over the breather made more noise than the engine, also when trundling along it made a noise that could still be heard above all the engine noise.
As good as it was, I would try every thing else possible before fitting this banister to my bike.
Simply because of esthetic reasons as well as the noise.
Maybe I am old fashioned, but there must be better ways to do it without spoiling the looks of the most beautiful motorcycle engine ever made.
Bernd
From someone who works on these bikes, I can say that i am not a fan, although i can see they do work well. From my experience you only need a more sizable breather if you intend on pushing the engine regularly past 80 plus MPH. Having said that, on the twin racer I built, I only used a larger bore timed stock breather that vents into the kickstart cover that is sealed in its lower half to the G50 plate and a couple of extra holes drilled to vent up near the hole where the clutch cable passes through. My road going Rapide uses a breather type inspection cap atop the front cylinder exhaust valve with a 3/8" bore hose running to the rear axle. If the bores and rings are in good condition and the heads seal well without using excessive amounts of torque on the head stud nuts, oh and use 3 mm "O" rings on the pushrod tubes instead of the stock type, you will have minimal oil leaks. Again I can see that folk might like to use them, and It is a shame the factory did not make the breather much better. But I have never used the elephant's trunk type breathers on any of the engines I have done.......To each his own.
Hello Greg,
Just out of interest. How did you drill the breather spindle, cause I thought it was hardened. Did you actually drill a finished spindle or did you do one yourself and had it hardened and ground afterwards?
Just out of interest. How did you drill the breather spindle, cause I thought it was hardened. Did you actually drill a finished spindle or did you do one yourself and had it hardened and ground afterwards?
I fitted an elephant trunk to my Rapide after it was rebuilt just to be sure. I am a lazy sod and after 15,000 m it is still there. The only thing that comes out of it is misty air. no real noise to speak of. I will probably move it onto the Shadow when it is rebuilt and fit a breather onto the front exhaust cap or widen the timed breather slot. Looks do not worry me as much as a (relatively) oil tight machine and reliability.