PCV valve (I think) modification - do I need it?

[oldGSfan]

I have an elbow fitting on my GS1100E turbo, tapped into the cover next to the breather outlet. I also have a brass one way check valve which I'm assuming function as the PCV valve.
Seems like a useful thing to have, and I'm curious: How else would the engines breathe with only that one breather outlet?

I Frankensteined an Empi VW air cleaner filter and cover to the original cleaner's backing plate. and added the breather tube from the Empi. I think I'll just get a new 'real' PCV valve and ditch the brass one, the size of it means too much adapting of hoses. Or if it's not needed I can just blank both ends off I suppose.

By the looks of the length and bend of the old breather hose, it dumps out ahead of the rear tire, is this really the case? It appears to go into that opening at the rear of the motor where the battery and carb overflow tubes go.

Not cool if so. I remember my brother's old '70 Bonneville had a hose all the way to the back of the rear fender.

 

[hillsy]

The breather is not a PCV as such - it's just a port to the camchain tunnel.

The original hose (the one still connected in your pic) went to the airbox.

Not sure why someone has put a second outlet on there - unless there was extra blow-by as you said it was a turbo?

 

[oldGSfan]

Yes I realize it's just a port, thanks for info on routing. I was mixed up on in vs. out but it makes sense now. But one breather seems lacking - where does the engine ingest air, just blow-by past rings?

The 2nd port seems to make it like an automotive system I'm familiar with, to compete the circuit, so it breathes filtered air in, and then (like my old Willys and other cars) routes the output into the intake manifold, not through the carb. There's no such port on the manifold below/past the carb, so that is maybe where a catch tank comes in?

It still is a turbo - see my thread here.

The breather is not a PCV as such - it's just a port to the camchain tunnel.

The original hose (the one still connected in your pic) went to the airbox.

Not sure why someone has put a second outlet on there - unless there was extra blow-by as you said it was a turbo?

 

[Rijko]

in standard trim the bike does not have much pressure in the crankcase, and the original port was to let the engine breathe, catch the occasional drop of oil vapour, and to dump toxic gases into the air filter to get burned off.

With a souped up engine, the pressure in the crankcase builds up higher and needs more room to escape. Think that's the reason for the extra breather on your bike.

Underneath that breather cover should be 2 wire meshes catching oil.
My bike never spat out a drop.
Seeing how clean your bike looks arount the extra port, looks like yours doesn't either.
The oil catch tank i think was mandatory in racing and was adopted on street bikes for the cool factor.
And it's good to catch that occasional drop of oil in a tank should it come out, better than on the engine.

 

[Rijko]

where does the engine ingest air, just blow-by past rings?

In the old days before compression meters were commonplace for the average Joe, that was one of the indicators for worn rings - block that breather port and open the oil filler cap, and see what comes out. Place your palm on the hole, pressure is bad and smoke even worse