Breathers
Seasoned HDF Member
Joined: Jul 2014
Posts: 8,590
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From: Cental, MI
Originally Posted by 98hotrodfatboy 
I'd much rather have a bottom breather.....
I'd much rather have a bottom breather.....A given... But... Not as Forgiving as a Head Breather.. A Shovel can really benefit from Crankcase evacuation... but PITA... on any of 'em.
Seasoned HDF Member
Joined: Jul 2014
Posts: 8,590
Likes: 3,358
From: Cental, MI
I blame EPA and Tree Huggers for the head breathers and Umbrella valves as well..
I have very Limited experience with head breathers... and do Not think they are as Efficient as a case Breather Anyway. And I don't care if I pollute just a bit of oil Mist!!
Since Most of my experience is a result of Drag Racing..I am adapting what I feel is pertinent for street use... I am trying to Help my Head breather, Breathe, by routing to the Intake... But...No Oil in my breather system.... Yet
Last edited by Racepres; Feb 7, 2019 at 09:12 AM.
Grand HDF Member
Joined: Nov 2009
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From: Tampa
Hence the terminal demise of all "marking territory" jokes around Harley Davidson.
Seasoned HDF Member
Joined: Jul 2014
Posts: 8,590
Likes: 3,358
From: Cental, MI
And yes... the head breather would need to be pretty badly Sumped to get oil outside the System...
I bet letting a Stroker Breathe thru those Heads is gonna be challenging... Drag Racers do it completely Differently... But... We ain't racing... just want to do the best we can with what we gots...
Dirt don't hurt
Joined: Jan 2011
Posts: 21,065
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From: Haslet Texas
No way in hell yer Harley will even come close to Achieving "negative pressure"... tho logic tells us it may...Experience Shows it is Impossible...Best we can hope is to let 'er breath uninhibited..and trust me... it will all be Exhale!!!
And yes... the head breather would need to be pretty badly Sumped to get oil outside the System...
.
And yes... the head breather would need to be pretty badly Sumped to get oil outside the System...
.
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Seasoned HDF Member
Joined: Jul 2014
Posts: 8,590
Likes: 3,358
From: Cental, MI
No... The valves can be removed without any real change... and the breather gear??? Maybe... I never seen one so bad that it Caused sumping...But, Maybe.
Dirt don't hurt
Joined: Jan 2011
Posts: 21,065
Likes: 4,561
From: Haslet Texas
Neither one will cause sumping but if either or both are bad you will be spitting oil out the breather tube wherever it's routed to.
