E: Engine Breather Timing: A long description of a different way (Part 1)

[erik]

T'he 2 valve BMW's have a breather which is a pertinax disc preloaded by a spring under a small aluminium dome with a connection for a tube looking a little bit like a one side closed banjo connection. Has anybody tried this to fit on a series D breather cap?

 

[vibrac]

T'he 2 valve BMW's have a breather which is a pertinax disc preloaded by a spring under a small aluminium dome with a connection for a tube looking a little bit like a one side closed banjo connection. Has anybody tried this to fit on a series D breather cap?

It is on the forum somwhere because I went and bought one and then found a car one that works fine in a normal hose pipe for a couple of quid, unfortunately on the forum search "BMW" is too short a search term and "breather" is a subject so well discussed as to melt the servers. I jumped back 10 pages of the search and found a thread entitled "Oh no not breathers again!" and I lost the will to look further "reed valve" might get you somewhere if you have the stomach.

 

[Bill Cannon]

T'he 2 valve BMW's have a breather which is a pertinax disc preloaded by a spring under a small aluminium dome with a connection for a tube looking a little bit like a one side closed banjo connection. Has anybody tried this to fit on a series D breather cap?

Yes I have and it improved the oil loss on my bike. I removed it as it was rather ugly and rebuilt the engine instead!
Bill

 

[erik]

i thought about BMW because the boxer engine has nearly the same Problem like a V-engine.both Pistons are lowering into the crankcase at the same time.realy the same pumping effect.with two breathers on the valve caps was my idea.

 

[bmetcalf]

Here is the reed valve:

https://shop.maxbmw.com/fiche/NotesParts/11111335712_4_B.jpg

Here is the assembly and the spring loaded alternative:

https://shop.maxbmw.com/fiche/Diagrams/B0000089.png?v=07242017

 

[timetraveller]

Has anyone tried the Enfield 'duck bill' system on a Vin and if so what were the results?

 

[mercurycrest]

Has anyone tried the Enfield 'duck bill' system on a Vin and if so what were the results?

I've had one on my A Comet for years. It marks it's spot when idling (the screws are backed way out on the adjusters) , but works well at speed... (maybe). At least it doesn't oil up the rear of the bike.

 

[Oldhaven]

Has anyone tried the Enfield 'duck bill' system on a Vin and if so what were the results?

While I am going to use the standard timed breather on my Comet project, and will use the information in this thread to some advantage, my use of an HD solenoid type compression release makes the valve lifter mechanism unnecessary. I have to plug the timing case exit point for it now and I am considering using a duckbill type breather tube there instead of a solid plug. That seems to be the cheapest and simplest version of a breather around. Has anyone used this port for a breather and does it make any sense? I know that when used as intended it is a prime area for oil leaks without some care being taken, perhaps from oil being thrown off the large idler. It's out of the way location is nice since it is not obvious, though in my case the access is very tight due to the gearbox mounting method I used.

Ron

 

[bmetcalf]

My 2007 Buell has three reed-type breathers, one from the crankcase

And one in each cylinder head (Item 1):

 

[Flo]

It is on the forum somwhere because I went and bought one and then found a car one that works fine in a normal hose pipe for a couple of quid, unfortunately on the forum search "BMW" is too short a search term and "breather" is a subject so well discussed as to melt the servers. I jumped back 10 pages of the search and found a thread entitled "Oh no not breathers again!" and I lost the will to look further "reed valve" might get you somewhere if you have the stomach.

Look for Manfred Kinne - he's done it and published a drawing.

BR

F