New Breather Filter Test *PICs*
Stellar HDF Member
Joined: Jan 2013
Posts: 2,721
Likes: 103
From: St. Louis, MO
Check how your engine oil looks after some miles without a vacuum on your crankcase.
You've gone back to the "road draft" system used back before 1968 when cars vented to atmosphere, PCV valves became mandatory then.
An important side benefit of providing a vacuum on your crankcase is that your combustion byproducts are removed from the crankcase and thus your bearings and engine components live a much longer life. Compare how clean modern engines are inside vs when we used to open up engines back in the day.
I ran a breather for a short time, until I realized my oil got filthy in no time, and, I didn't like the oil spots and oil mist stink when I parked in my garage.
You've gone back to the "road draft" system used back before 1968 when cars vented to atmosphere, PCV valves became mandatory then.
An important side benefit of providing a vacuum on your crankcase is that your combustion byproducts are removed from the crankcase and thus your bearings and engine components live a much longer life. Compare how clean modern engines are inside vs when we used to open up engines back in the day.
I ran a breather for a short time, until I realized my oil got filthy in no time, and, I didn't like the oil spots and oil mist stink when I parked in my garage.
Road Master
Joined: Sep 2012
Posts: 875
Likes: 10
From: Corp of Discovery trail, Missouri
All I did is Google the subject and read a lot of excellent info. I would say the positives far out weigh any negatives of doing this mod.
Look at post 33. This looks like an extreme case of blowby probably caused from oil overfill but it shows the result of having oil in the combustion chamber and its consequences. If I get 1% of that carbon build up it is to much for my liking hence the reason I re routed the vented exhaust gases and oil misting.
https://www.hdforums.com/forum/touri...-filter-4.html
Look at post 33. This looks like an extreme case of blowby probably caused from oil overfill but it shows the result of having oil in the combustion chamber and its consequences. If I get 1% of that carbon build up it is to much for my liking hence the reason I re routed the vented exhaust gases and oil misting.
https://www.hdforums.com/forum/touri...-filter-4.html
Last edited by kneesinthebreeze; Jan 10, 2015 at 04:14 PM.
Road Warrior
Joined: May 2013
Posts: 1,430
Likes: 55
From: Florida
The Venturi effect (Pulling oil vapor/mist) seems to come from changing the stock to a High Flow A/C working aginst the umbrella valves. And the location of the vents on a lot of aftermarket and SE backplates don't aim right into the TB thus the pooling and dripping effect. The Crankcase pressure vented out to a catchcan or the atmosphere/ground dosen't produce as much oil as what I had seen collecting/pooling/dripping from my Air Filter. Either way I don't want the hot oily mostly exhaust vapor going into my engine. JMHO, FWIW
Elite HDF Member
Joined: Jul 2008
Posts: 4,762
Likes: 12
From: north jersey
All I did is Google the subject and read a lot of excellent info. I would say the positives far out weigh any negatives of doing this mod.
Look at post 33. This looks like an extreme case of blowby probably caused from oil overfill but it shows the result of having oil in the combustion chamber and its consequences. If I get 1% of that carbon build up it is to much for my liking hence the reason I re routed the vented exhaust gases and oil misting.
https://www.hdforums.com/forum/touri...-filter-4.html
Look at post 33. This looks like an extreme case of blowby probably caused from oil overfill but it shows the result of having oil in the combustion chamber and its consequences. If I get 1% of that carbon build up it is to much for my liking hence the reason I re routed the vented exhaust gases and oil misting.
https://www.hdforums.com/forum/touri...-filter-4.html
Elite HDF Member
Joined: Jul 2008
Posts: 4,762
Likes: 12
From: north jersey
Yes, we've posted vdop's pic before...it is pretty amazing how clean it is after 5k miles.
Here is a thread where he explains what engine it's in, how he rides etc. Post #20 at this thread- https://www.hdforums.com/forum/touri...-587-ac-2.html
Here is a thread where he explains what engine it's in, how he rides etc. Post #20 at this thread- https://www.hdforums.com/forum/touri...-587-ac-2.html
Hey Kevin if I want to use this particular kit in this link http://dkcustomproducts.com/Twin-Cam...-ACI-TC-BR.htm
but I'd want to use braided hoses instead of that black rubber one. How long would my braided hose need to be?
Thanks.
Last edited by Alain; Jan 10, 2015 at 08:03 PM. Reason: Forgot to post the link
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Seasoned HDF Member
Joined: Dec 2008
Posts: 19,745
Likes: 1,183
From: Jamestown, CA
_____Good Idea Alain , I'll keep Post-in as I get more Miles on-er .
Tourer
Joined: Apr 2014
Posts: 318
Likes: 24
From: London, UK
So what we need to avoid dumping hot oily air into the combustion chamber but still achieve some crank case vacuum to draw the mist etc away from the oil (to keep it cleaner) is a cleverly shaped filter placed in the airflow to generate a bit of vacuum in the hose from the movement of air over the filter as the bike moves. Any ideas?