Mikee Minute #8 - Crankcase Recirculation Systems

Tips and Recommendations from Guru Mike Nixon

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mikenixon
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Re: Mikee Minute #8 - Crankcase Recirculation Systems

#46

Post by mikenixon »

The catch can idea is good, it's what racers do. But as to whether I think the filter should be right on the crankcase or remote, I can't see it making much difference. I think if esthetics are important. then a filter attached to the original hose but tucked up into the shelter cover or behind a sidecover makes a lot of sense.
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Re: Mikee Minute #8 - Crankcase Recirculation Systems

#47

Post by Sidecar Bob »

Right now the breather is connected to a barb near the top of the airbox with a hose inside the box so that the condensate drips onto the bottom near the drain. The filter is on the end of a hose connected to the airbox drain.

I can't say about other years but the '83 'Wing came with a catch can that was supposed to be emptied periodically but it was really easy to forget so I replaced it with an old fuel filter. That worked well until I added the sidecar and then the oil consumption increased dramatically. I had a similar filter on the original airbox/breather drain on the 650 from when I put that bike together and it and it always used a lot more oil than it should have. After I redesigned its breather/drain setup the oil consumption decreased significantly. My theory is that the wind that blows between the bike & the sidecar at speed siphons oily air out of the crankcase.

BTW: One of the guys on the Canadian URal & Dnepr riders (CURD) forum has built a breather setup or his Ural with a piece of 1/2" copper pipe that carries the condensate to a catch can beside the rear fender. His catch can is a vented metal container (he is a machinist) that can hold several ounces with a stopcock from a car radiator in the bottom for easy draining.
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Re: Mikee Minute #8 - Crankcase Recirculation Systems

#48

Post by robin1731 »

The reason racers use a catch can is the rules. It keeps oil off of the track. Otherwise we would just dump it on the ground. The catch can would basically be a maintenance thing. You would have to remember to empty it once in awhile.
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Re: Mikee Minute #8 - Crankcase Recirculation Systems

#49

Post by pidjones »

Let me suggest properly maintaining the original system as an option. In days long gone,most roads were dirt or gravel, and the oil from the engines kinda help keep the dust down. Move up to paved roads and increased traffic - a black stripe down each lane and a puddle at every stoplight from the old road draft systems. When I first started riding it was imperative to watch out for that and avoid. Now it is usually radiator overflow or AC condensation at the lights, and junkers dumping occasionally (luckily, they don't run long enough to create a big problem -but watch for their trails!) I was taught to drive a cage as if I was straddling the black stripe. Today, that stripe is barely discernable on many roads.

I know we are a very small percentage of the motor traffic on the highways. What if the trucks decided it was keeping their intakes gummed up and removed the system, then the taxis, then the delivery vehicles, then police cars, then.... I intend to keep my crankcase vapor recycle system functioning as Honda designed it. This means cleaning, draining, and checking regularly. The racers have it right, I think. ANY oil on the road is a bad thing, particularly if your life depends on rubber-to-pavement friction in a high speed up-hill sweeper!
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Re: Mikee Minute #8 - Crankcase Recirculation Systems

#50

Post by robin1731 »

pidjones wrote:Let me suggest properly maintaining the original system as an option. In days long gone,most roads were dirt or gravel, and the oil from the engines kinda help keep the dust down. Move up to paved roads and increased traffic - a black stripe down each lane and a puddle at every stoplight from the old road draft systems. When I first started riding it was imperative to watch out for that and avoid. Now it is usually radiator overflow or AC condensation at the lights, and junkers dumping occasionally (luckily, they don't run long enough to create a big problem -but watch for their trails!) I was taught to drive a cage as if I was straddling the black stripe. Today, that stripe is barely discernable on many roads.

I know we are a very small percentage of the motor traffic on the highways. What if the trucks decided it was keeping their intakes gummed up and removed the system, then the taxis, then the delivery vehicles, then police cars, then.... I intend to keep my crankcase vapor recycle system functioning as Honda designed it. This means cleaning, draining, and checking regularly. The racers have it right, I think. ANY oil on the road is a bad thing, particularly if your life depends on rubber-to-pavement friction in a high speed up-hill sweeper!

All good points. And I too have a catch can on the race bikes. But they get regular maintenance like anything else. I'll bet most with the stock setup don't get that. Although they should.
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Re: Mikee Minute #8 - Crankcase Recirculation Systems

#51

Post by NewWinger »

I just rebuilt my breather element on my 77GL.
The inside of the breather element was full of rust powder and disintegrated filter element. I just cut up a fram breather element and used the media between the screens and put it back together after cleaning. I will keep the hose from the crankcase attached and put a small catch container on the outlet of the element housing to illuminate the discharge to the road.
As far as the PCV hose that goes on the air box can I block it or put a small breather element on it? :?:

This recent activity on this tread is very timely for me as I am working these things out.

regards to all
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