Oil mist from breather & Hayden Krank Vent Plus

[1340evo]

Hi Again.. 89 bottom breather and I have the breather running to a small K&N chrome filter thing under the bike. But it's misting up the underside of the bike.. Any thoughts on how best to stop it?

I have seen on here before about oi catch tanks and I could do that, but also remember people talking about Hayden Krank Vent Plus having a posative effect on misting issues.

Any thoughts on this please... Maybe silver was not the best choise to paint my engine 

[HogMike]

I ran my breather tube from the engine vent to a catch can mounted behind the primary cover.
Took off the little breather screen and ran tubing from that hole to the bottom of the rear fender. Can't really see anything and I empty the can every few rides.
Bike stays clean.
Works for me for years.
 

[Hossamania]

Has the filter been cleaned on a regular basis?

[JSD]

Plastic breather timmer gear warped

[JW113]

Jog my memory, didn't you just rebuild this engine? If so, how many miles?

The krank vent won't keep it from exhausting oil mist out the breather, it's job is to hold a partial vacuum inside the crankcase. If you have blowby, it's going to come out krank vent or no.

-JW

[1340evo]

I've got about 750 miles on now since re-build and still on mineral oil, but does not appear to be getting any better. It's only mist that's coming out but collects on the small filter and local area so is something I wipe off every now and then.
Its a bottom breather and they all do it or so I'm told... is a catch tank the way forward then? have see some posts saying the valve solved the misting issue?
BTW, I have a steel valve that replaced the plastic one....

[JW113]

Where is the outlet (filter) physically located?

By all means use some sort of Krank Vent, it does more to hold oil in the motor rather than ooze out through the seams, and also helps with ring seal. I don't have much use for those filters at the end of the breather hose, just makes a mess from my past experience. I just run the hose to the back of the frame, and point it at the ground off to the side of the rear tire.

-JW

[1340evo]

its here, so lower than the outlet which may be part of the issue.

So would running a Hayden Krank Vent Plus hold the oil in from the vent do you think.. people say thay work for them stopping oil misting out.
Do you just plug the thing in and run with the existing system?
Are there other types to try that may work better?

If you don't have a filter on the end can it drag things into the engine?

[Ohio HD]

The Hayden vent will not keep oil from coming out of the breather hose. It only stops air flow from going into the motor. It's a one way valve just like the S&S valves that are much less expensive.


S&S 50-8122

[Ohio HD]

All that the expensive Hayden unit does is house the $4.00 Twin Cam breather flap, part number 26858-99. A lot of money for a housing for the $4.00 flap.

[1340evo]

okay, thanks for this. I guess if I fit one of these in-line I can run the pipe open to ground as it won't suck back in....
With a bottom breather can I just plug it into the tube with everything else still installed? Obviously the right way around to it allows pressure out. 

[kd]

With the mount you use on your filter you have created a type of pitot tube.  That's drawing the mist out of the crankcase and venting it into the turbulence as you ride. It is possible repositioning it to a clean atmosphere up higher may resolve it.

I have 2 head breathing Evo's vented with a long tube that ends on the right rear side of the trans and made sure it was terminated up out of the draft.  They work well with only the occasional single drip after a long hard run, but as said, they are head breathers.

I don't remember if you are running a chain or belt.  If it's a chain, another alternative is to direct the hose to directly above the trans sprocket and terminate it there. It will make good use of the occasional venting drip.

[1340evo]

good call, it may be acting as a kind of venturi where it is?

I did suggest oiling the chain with it myself but told the 'O' rings in the chain did not like engine oil? not sure why?

I may also get one of the above valves to create negative pressure in the engine whilst I'm at it ...

 

[Ohio HD]

With the mount you use on your filter you have created a type of pitot tube.  That's drawing the mist out of the crankcase and venting it into the turbulence as you ride. It is possible repositioning it to a clean atmosphere up higher may resolve it.

Good call

Your old enough to remember the road draft tubes that cars and trucks used before the PCV was invented. They changed the angle of the cut off of the vertical tube catching air under the motor to tune the amount of average suction.

[Ohio HD]

[Will-Run]

With the mount you use on your filter you have created a type of pitot tube.  That's drawing the mist out of the crankcase and venting it into the turbulence as you ride. It is possible repositioning it to a clean atmosphere up higher may resolve it.

I have 2 head breathing Evo's vented with a long tube that ends on the right rear side of the trans and made sure it was terminated up out of the draft.  They work well with only the occasional single drip after a long hard run, but as said, they are head breathers.

I don't remember if you are running a chain or belt.  If it's a chain, another alternative is to direct the hose to directly above the trans sprocket and terminate it there. It will make good use of the occasional venting drip.

Would there be any advantage to putting one way valves on setups like yours?. Thank you.

[kd]

With the mount you use on your filter you have created a type of pitot tube.  That's drawing the mist out of the crankcase and venting it into the turbulence as you ride. It is possible repositioning it to a clean atmosphere up higher may resolve it.

I have 2 head breathing Evo's vented with a long tube that ends on the right rear side of the trans and made sure it was terminated up out of the draft.  They work well with only the occasional single drip after a long hard run, but as said, they are head breathers.

I don't remember if you are running a chain or belt.  If it's a chain, another alternative is to direct the hose to directly above the trans sprocket and terminate it there. It will make good use of the occasional venting drip.

Would there be any advantage to putting one way valves on setups like yours?. Thank you.

There was a thread about a couple of months or so back that Ohio was in relating to the S&S valves that may answer that question.  I just went raw and open because the 3/8" tube I used was about 6' long to the exit end.  I wasn't concerned with any backward feed at that length.  I figured I would keep it simple and try that first.  I can say the misting (drips from the breather onto the engine) was regular when running hard on hot days and it was resolved after that.  Previously I used a 2" long folded piece of absorbent paper towel between the bottom of the filter and the cover.  After the hose working I didn't see any reason to fool with success.  .

I searched using - s&s one way breather valves and found a few threads I remember discussions that may help you decide.   My hose starts out at the carb ase and travels to the front of the engine and down then to the back so it may be considerably longer than what you are looking at.   The searched threads may be more helpful if a position change doesn't work.  I'd be inclined to get it out of the wind and try a new position first.

[1340evo]

6 foot of pipe !.. that must restrict it a lot I'd of thought, especially if you get any sump areas in there where oil collects?

[kd]

6 foot of pipe !.. that must restrict it a lot I'd of thought, especially if you get any sump areas in there where oil collects?

That's 6' of 3/8" ID tube for the full length. All considered it is way less restrictive than 1 fitting or the S&S one way valve ports. 

[1340evo]

ok, yes it would have to be for that length 

[1340evo]

Did a 15-20 mile run tonight with the breather pipe into a 4" x 1 1/2 dia catch bottle and this is what came out. There is quite a lot of condensation in there. I'll see if it settles out into oil?
This is with the pipe going down still. I need to get some more pipe and run it up like sugested....

[JSD]

Short runs build condensation motor not getting hot. Cover oil cooler if running cold weather.

[kd]

Your pistons and head surfaces will thank you.  The blanket of carbon is formed by burning the oily  contaminated air when the crankcase vents that crud through the breather into the cylinders.

[1340evo]

So what's the original breather pipe direction for the bottom breathers? Where did the pipe go?

As you see I have a straight pipe out of the case now, but I also have a 90 deg fitting of the same size in my spares box so wondering if originally it came out and went through 90 deg somewhere?

Also, if I did point it up and take the pipe straight up first so any oil ran back into the engine, what would happen if the pipe eventually filled with oil and it could not breath? could this happen??

[Ohio HD]

Originally it went to the are filter housing.

If the motor is expelling oil out of the breather line, then oil will eventually find the end of the hose and puke out no matter how it's arranged on the bike.