Labyrinth wanted.

User avatar
buzby
Posts: 190
Joined: 14 Apr 2006 18:31
Location: southampton

Labyrinth wanted.

Post by buzby »

Can somebody please help me , I need a labyrinth, that's the plastic baffle that goes in the crankcase breather pipe. Mdina have none.

thank you,
Dave.
David
75 350 Strada, 76 350 Strada, 76 350 Sport. 80 250 vee, 72 Triumph TR5T and 81 Honda CB250RS
norbert
Posts: 750
Joined: 15 May 2007 15:15
Location: Lübeck/Germany

Re: Labyrinth wanted.

Post by norbert »

If you don´t find them nearer, I should have a pair of them anywhere. Normaly there are two labyrinth in the tube, but Rocinante wears only one for years in a Gardena-garden-tube without any problem :wink:

norbert
Steve Brown
Posts: 1390
Joined: 12 Nov 2007 23:44
Location: Leicestershire

Re: Labyrinth wanted.

Post by Steve Brown »

As Norbert says, one will be fine. My own bike was supplied new in 1977 (76 model-correct shade of red) and works fine still.

For my Camel build I couldn't find one and used a non return valve intended for diesel fuel systems. That works fine too. Available from motor parts factors everywhere for a few quid.
All donations to the rest home for old Camels, Leicestershire.
harrymuffin
Posts: 292
Joined: 07 Apr 2014 16:06
Location: west midlands

Re: Labyrinth wanted.

Post by harrymuffin »

Unfortunately I have just sold two. If you should get really desperate then I can knock you a couple out, I have aluminium ones in my pipes. but plastic would be just as easy.
User avatar
buzby
Posts: 190
Joined: 14 Apr 2006 18:31
Location: southampton

Re: Labyrinth wanted.

Post by buzby »

Thanks everybody. I read somewhere, possibly on here, that they cause the necessary back pressure so that oil reaches the cylinder heads.
David
75 350 Strada, 76 350 Strada, 76 350 Sport. 80 250 vee, 72 Triumph TR5T and 81 Honda CB250RS
User avatar
Daddy Dom
Posts: 512
Joined: 16 Nov 2006 19:48
Location: Auckland, New Zealand

Re: Labyrinth wanted.

Post by Daddy Dom »

A job for someone with a 3D printer, I reckon.
MRC 3082½
User avatar
Ming
Posts: 798
Joined: 01 Aug 2014 16:32
Location: France
Location: Central France

Re: Labyrinth wanted.

Post by Ming »

Stainless scouring pad?
Steve Brown
Posts: 1390
Joined: 12 Nov 2007 23:44
Location: Leicestershire

Re: Labyrinth wanted.

Post by Steve Brown »

buzby wrote:Thanks everybody. I read somewhere, possibly on here, that they cause the necessary back pressure so that oil reaches the cylinder heads.
The effect is more like a one way valve, hence why my mod works, it isn't a new idea and they get used to control the crankcase breathing on many classic car and bike engines very effectively. If you bung it up with something like wire wool! :? you will create positive pressure in the crankcase, lose perfomance and gain a lot of oil leaks. Then you can really call it a proper classic! :wink:

3D printer is a good idea though!
All donations to the rest home for old Camels, Leicestershire.
Steve Brown
Posts: 1390
Joined: 12 Nov 2007 23:44
Location: Leicestershire

Re: Labyrinth wanted.

Post by Steve Brown »

Ming wrote:Stainless scouring pad?
!!! Noooo!!!
All donations to the rest home for old Camels, Leicestershire.
User avatar
buzby
Posts: 190
Joined: 14 Apr 2006 18:31
Location: southampton

Re: Labyrinth wanted.

Post by buzby »

I ended up using the one way valve for car or bike engines as recommended by Steve. It fits inside the breather pipe, it's cheap, you can't see it and it works. Thanks everybody for the advise.
David
75 350 Strada, 76 350 Strada, 76 350 Sport. 80 250 vee, 72 Triumph TR5T and 81 Honda CB250RS
simonnorthroad
Posts: 388
Joined: 16 May 2017 10:57
Location: Bath, UK

Re: Labyrinth wanted.

Post by simonnorthroad »

where did you get it from? Im interested in one
User avatar
buzby
Posts: 190
Joined: 14 Apr 2006 18:31
Location: southampton

Re: Labyrinth wanted.

Post by buzby »

David
75 350 Strada, 76 350 Strada, 76 350 Sport. 80 250 vee, 72 Triumph TR5T and 81 Honda CB250RS
George 350
Posts: 450
Joined: 16 Jun 2007 09:43
Location: Northampton

Re: Labyrinth wanted.

Post by George 350 »

Surely you want oil mist to go 'upstairs' to the rockers? If you put a non-return valve on the crankcase breather, then every time the pistons go up you will be sucking air into the rocker covers due to there now being a vacuum in the crankcase and any oil mist will come down with it.
(Any blowby past the rings shouldn't be any where near enough to fill the vacuum unless your engine is really shagged).
I remain of the opinion that the crankcase breather needs to have a controlled 2-way flow, so that the road draught under the engine can draw oil mist up to the top end.
98000 miles on original rockers suggests that the original design works.
Regards, George.
George
350 sport 1978, 350 Strada 1978
650 Norton 1967, 650 Kawasaki 1977 and 650 Enfield 2019
User avatar
Ming
Posts: 798
Joined: 01 Aug 2014 16:32
Location: France
Location: Central France

Re: Labyrinth wanted.

Post by Ming »

For what it's worth - I have always thought that the labyrinth in the crankcase breather was no restriction to air, but was simply something for any oil mist to condense on and fall back into the engine. ie the crankcase would be always at atmospheric pressure. Am I wrong?
Zed1
Posts: 18
Joined: 18 Dec 2016 09:59
Location: Bedfordshire

Re: Labyrinth wanted.

Post by Zed1 »

Should all models have these ? I've a Excalibur and when I swapped the breather tube it was just a empty tube ,if needed would 1 of the non-return valves be ok thanks Paul
Post Reply