Crankcase vent to the oil tank... or not. Why wouldn't I?

So I understand about the oil vapor, trying to condense it into the tank, vent only the gases. BUT.. I've got the reed XS650 valve ready to go in, I can't help but wonder if that valve, connected to a road draft tube out by the license plate, would make life in the oil tank so much more happy, less huffing and puffing, less leakage at the cap. Has anyone done this? Any reports on how it works?

Re: Crankcase event to the oil tank... or not. Why wouldn't

I have seen this on Jay Leno's JPN.

Re: Crankcase vent to the oil tank... or not. Why wouldn't I

With my 850 I just put the vent hose off the one-way-valve, (which is just off the timing case) straight down between the engine and tranny case. It may drip a drop or two if any, I figure no sense blowing all those nasty blow-by gasses into the oil tank along with a lot of moisture. Environmently it would be better if somehow it could be hooked up to manifold vacuum to evacuate the case just like a true automotive style PCV system.

GB

Re: Crankcase vent to the oil tank... or not. Why wouldn't I

sure, why not?

I have my 73 breather hooked up to a one way valve that then goes to piss gently and rarely on my rear chain

no reason it has to have anything to do with your oil tank

I have a rubber plug in the oil tank tube where it would have plugged in to

and I have a hose line on the tube that exits the oil tank and goes in to an open plastic bottle in my battery area
so the oil tank can still breath out, should it choose to do so

Re: Crankcase vent to the oil tank... or not. Why wouldn't I

I assume your breather comes off the timing chest so that you don't evacuate oil thru it when you are wet sumped?

Russ

Re: Crankcase vent to the oil tank... or not. Why wouldn't I

rvich said:

I assume your breather comes off the timing chest so that you don't evacuate oil thru it when you are wet sumped?

Russ

Click to expand...

yes, '74

Re: Crankcase vent to the oil tank... or not. Why wouldn't I

I run mine into a dump bottle that sit between the engine mounts, its just a old plastic bottle with a screw top, I also run a breather hose from the oil tank to the same bottle, the two hoses just sits in the top where the bottle cap use to screw on, but there is still some space between the hose for the dump bottle to breathe, it don't get much oil in it and only emty it once a year (about a oz or 2 of oil) as for wet sumping mine has never had that problem in 36 years of ownership.

Ashley

Re: Crankcase vent to the oil tank... or not. Why wouldn't I

I'm just about to connect mine up after fitting a reed valve behind the rear of the timing cover, I would of thought that running from there to the oil tank and another from the oil tank back in to the standard air filter housing would be fine.
No???

Re: Crankcase vent to the oil tank... or not. Why wouldn't I

There are reasons its long traditional to disconnect the Norton Chain oiler and the Norton oil tank vent into low pressure air box thence into intakes, both make a mess, one can just wipe away but the other gets coked onto the chamber, valves and pistons.

Seems many ways to effectively vent oil tank and cases to outside, that don't take much oil with it. I compromised the best or worst of these by a single PVC valve up close to the tank to keep hot oil vapors to a minimum then vent tank most direct route to the ground on RH side out of line of chain grit collection and rear tire patch.

Exhaust extractor is another way to try not to suck oil out with the blow by.

Re: Crankcase vent to the oil tank... or not. Why wouldn't I

Mine is an ancient system that comes off the timed breather on the drive side and goes to the top of the central oil tank which probably none of you have, but anyway, there's a breather that goes into the air box from the central oil tank and it drips oil in the filter and then drips down on to the top of the gearbox and you can guess where it goes from there. Anyhow, I attached a tube to the oil breather and attached it to a large pill bottle that I place between the engine and gearbox. Doesn't drip down on the road and I clean it out once in a while, maybe yearly. Not much goes in there, but when it goes on the gearbox, it seems to go everywhere.



Dave
69S

Re: Crankcase vent to the oil tank... or not. Why wouldn't I

No way I'm venting that out the back. You don't want that stuff on the road or worse, on your rear tire. Vent to oil tank and don't worry about it. At least on the 72 the oil tank vents to the air box, all good.

Re: Crankcase vent to the oil tank... or not. Why wouldn't I

Oh swooheroo, its going to come out any way and its just silly to worry about where - other than prevent a mess on bike or inside chambers but for sure its a non issue on road or tire even if aimed right at the patch. A daily regular rider leaves more oil pollution behind by the dead bug bodies oils. Unless its a polished copper or chrome plated 1/4" pipe factory fitted and mounted like the leather belt drive total loss bikes, a run of oil vent hose along a bike length just looks so so, well, Arkasnsas Micky Moused : )

Even my Trixie blown gasket smoker with twice the ring gap blow by does not drip oil out her straight down tank hose. She did use and leave oil behind last 1000 miles but not from the normal oil system exits. Catch bottle look cool on race bikes but crude patch job eye sore on road bikes to me. If bottle only needs attention once every few years, why not just a plugged hose with a tiny vent hole up high, pull plug now and then, then tuck hose back neatly in place. If you really want the racer cluttered look with clean function then should also add their under frame catch tray and diaper.