Like I said earlier, if the H-D engineers didn't have to put that **** back in there they wouldn't. I bet they will agree that the best place for that **** is any where but in the intake.

 

A question for those of you that have installed cans that have to be emptied. Why? Why not run it under your bike and to the ground?
The amount coming out is negligible. You will run through 5 times what comes out in a couple hundred miles. (Those numbers are just WAG so take a pill)

 

The goo will find it's way all over the underside of the bike and the rear wheel. Also when you park the bike in the garage you will need to remember to set an oilsorb pad under the area at the end of the hose. Seems that an external catch can that is easily accessed can be emptied without much fuss. Just my 2 cents.

 

 

For the sake of arguing, you run your **** the way you want, and I and a lot of others will do it the way we want. My pistons will remain clean and carbon free. As I said earlier I have seen first hand the difference in pistons with the breather lines going into the intake verses being vented away.

 

False..
1) the system does not require vaccum to pull the pressurized air from the case - the air is pressurized and drives itself out.
2) the vacuum does nothing to reduce case pressure.
3) the vapor does nothing for upper cylinder lubrication. That is not how 4 stroke gas engines are designed. It's not a 2 stroke.

Completely False. The system will not "collapse" if you do not run the breather tubes into the intake.
Again the introduction of EPA mandates is the only reason these gasses are directed into the intake to be burnt. Not because of a system or performance dependency. The system runs fine without it.

Bottom line, the breathers only point into the intake as a convenient place to dispose of the escaped gasses as to not hurt the environment.
Point of reference, older (before EVO) 4 stroke Harley engines did not have breathers going into the intake.
These gasses exited the bottom of the engine case (without vacuum) and went either into the primary or back to the oil bag or sometimes the ground.

That all said, does it matter? No. The engine does not care. You may care (about intake, valve, and piston cleanliness), and that's alright. America.

 

 

I've been following this thread and some of the information/opinions are laughable. I subscribe to the external breather group and have been riding a HD since 72, well before the time when they started to vent the crankcase into the carburetor now throttle body. I simply vent to the ground and can also confirm that none of the vented oil ends up anywhere on my underside/saddlebags/tires. Granted I'm currently riding a 14 FLHTK so maybe the M8 vents more oil than the twin-cam 103 but I wouldn't think so. I think what really deters most folks from doing this mod has to do with warranty because it is illegal to modify an EPA requirement. Also I felt that it would be better to not have hot oxygen deprived gases being pumped directly into my stage 1 cold air intake..