I, like a lot of others, have vented their breathers to the atmosphere to keep the oil from pooling at the bottom of the AC housing. (think early '60's automotive road draft tubes....if you're old enough) Why couldn't an individual tie the AC breather tubes/vents via a hose or tubing to a fitting on the oil fill cap that has been drilled and tapped ?? Of course to properly vent the crankcase, you'd have to vent the cap also, but I don't see this as a problem. (drill and adapt a small standoff, then attach a small breather from K&N or similar) All the oil from the AC breathers tubes/vents would then drain directly into the crankcase through the filler cap but the crankcase oil vapors would still be vented to the atmosphere through the standoff and small breather attached to it. I've used the search function to try and find an exploded diagram of the TC engine to see if it would vent properly with this setup, but have been unable to find one. Has anybody done this?? Would it work?? Your thoughts and comments are welcome.

 

with oil cap off, you may feel the pressure surging, I think that to time pulses from the breather to the oil fill would be a challenge.

so a vented reservoir that returns oil to the tank by gravity?
on a recent model there would be room over top of the starter- until the header heat set it on fire.

1st day in auto shop at CC, instructor shows us film of LA freeways in the 50's, then the 70's. the early film shows the center of the lanes dark from the road draft--- imagine riding that in the rain!

Mike

 

Road Draft Tubes! ... Damn ... you are old! Haven't heard that term in many many moons! Not too sure about venting back into the oil tank. In essence you're putting a "positive charge" back into the system. May get messy. I ran the vent line on my EVO down and out to a simple filter wiith a PCV Valve used as a check valve just before the filter. Never had a problem with that setup. Not so sure about the TC Engine though .. but I think it should work.

 

I'm (only??) 55, didn't start driving until '72 but have studied automobiles and their related components all my life. (hence the screen name)
I currently have my AC vent tubes drilled and tapped and have installed two brass fittings with nipples. I've run a hose from each to a T fitting, then a single hose down under the bike. The oil drains down the hose and (theoretically) drips to the ground, but it actually blows back underneath the bike creating an oil slick on the frame, oil pan, etc.

 

I was thinking about adding a vent tube to my bike, except the part where it run out on the road. My Idea was to have a small 1 pint square flat oil can that is vented at the top installed on the bike and run the vent tube to that. I would attach this to the lower frame in the void space just behind the oil cooler/voltage regulator location and add a drain plug at the bottom of the oil can. Collect the oil, vent the crankcase, then drain the oil out of the small oil can at every oil change. This would keep the oil off the bike, the road, and most importantly outta the air cleaner. Are there any manufacturers out there that would make something to test this application?

 

Venting the head breathers back into the oil tank isn't venting anything. And trying to drain off oil pushed out of a vent tube, back into the oil tank is unlikely to work either due to pressure wanting to push the oil back out. The best system is still venting it into the air cleaner where eventually it gets sucked into the intake and burned. You can vent externally, but will get some oil dripping at some point. No way around it.

 

Run the hoses to a T and up under the tank and drill and tap the frame. What little mist makes it up will keep your internal frame rust free and gravity in the hose will take care of the rest. Just a thought?

 

or you could just put a half a quart less oil in....

 

My bike runs warm enough without shorting it any amount of oil.


Guntoter: There shouldn't be any pressure in the oil tank because it too will be vented to the atmosphere via the standoff and attached breather. Remember the SB Chevys in the '60's where they had the oil fill tube with a breather attached to the top of the tube?? (this was before PCV valves) That was for crankcase ventilation. I'm proposing the same setup, only with an additional hose running from the AC to the standoff for oil drainback. I see no problems with a setup like this, but am asking because I haven't seen it done this way before and I can't figure out why nobody has done it. surely there must be a reason.

 

Shorting your oil tank 1/2 qt. will not make your motor run hotter.
Your idea may work but , as John Wayne said in The Shootist, "you're taking the long way around the barn".
What would be more effective would be to have the rocker boxes vented out the top, instead of the side of the head, using a PCV valve. Then gravity would keep the oil in the rocker box. It'd be ugly, but effective - just like the aforementioned SBC.