Breathers
Seasoned HDF Member
Joined: Jul 2014
Posts: 8,554
Likes: 3,309
From: Cental, MI
Why Not keep yer **** tuned and in good order, while using the induction system to help with evacuation??? or ... is evacuation not necessary??
I don't but... it may be best!!!
Let's face it... an oil "problem" is in fact a "problem"... should be Fixed...Maybe?
Last edited by Racepres; Feb 5, 2019 at 10:55 PM.
Banned
Joined: May 2018
Posts: 4,576
Likes: 978
From: Viet Vet, crossroads
A "Dry" Sump System works really well if designed correctly..-if- is the word.
We have to remember this is a very old engine design and has worked.
It worked when it was a small cube and lower HP.
It has been made to work for a century.
TYhe EPA mandated their BS about the draft tube and PCV valves back in the late 1960s and this mandate has crept
even to the MC engines, as the idle hands of bureaucracy needs to prove they are doing something ..even if it is retardedly stupid.
The "dry sump systems work well in aircraft, sports cars like the big Porsche engines, and lots of others.
It always provides positive oil Pressure under most circumstances..
Bottom line is HD could have done better, but they chose the antiquated archaic way of doing it.
We have to remember this is a very old engine design and has worked.
It worked when it was a small cube and lower HP.
It has been made to work for a century.
TYhe EPA mandated their BS about the draft tube and PCV valves back in the late 1960s and this mandate has crept
even to the MC engines, as the idle hands of bureaucracy needs to prove they are doing something ..even if it is retardedly stupid.
The "dry sump systems work well in aircraft, sports cars like the big Porsche engines, and lots of others.
It always provides positive oil Pressure under most circumstances..
Bottom line is HD could have done better, but they chose the antiquated archaic way of doing it.
Dirt don't hurt
Joined: Jan 2011
Posts: 21,059
Likes: 4,534
From: Haslet Texas
A "Dry" Sump System works really well if designed correctly..-if- is the word.
We have to remember this is a very old engine design and has worked.
It worked when it was a small cube and lower HP.
It has been made to work for a century.
The EPA mandated their BS about the draft tube and PCV valves back in the late 1960s and this mandate has crept
even to the MC engines, as the idle hands of bureaucracy needs to prove they are doing something ..even if it is retardedly stupid.
The "dry sump systems work well in aircraft, sports cars like the big Porsche engines, and lots of others.
It always provides positive oil Pressure under most circumstances..
Bottom line is HD could have done better, but they chose the antiquated archaic way of doing it.
We have to remember this is a very old engine design and has worked.
It worked when it was a small cube and lower HP.
It has been made to work for a century.
The EPA mandated their BS about the draft tube and PCV valves back in the late 1960s and this mandate has crept
even to the MC engines, as the idle hands of bureaucracy needs to prove they are doing something ..even if it is retardedly stupid.
The "dry sump systems work well in aircraft, sports cars like the big Porsche engines, and lots of others.
It always provides positive oil Pressure under most circumstances..
Bottom line is HD could have done better, but they chose the antiquated archaic way of doing it.
Banned
Joined: May 2018
Posts: 4,576
Likes: 978
From: Viet Vet, crossroads
Don't try to make gravity do what it does not want to do.
Whilst the original design was to use the pressure from the pistons to help with scavage and lubrication,
it was not ever in their vision to attempt to make AOS system out of it.
Revert to timed bottom breathing and all will be fine.
That is "was" how it worked.
To change that one will have to fit suction line into the bottom of the crankcase and build a propper scavenge pump.
This a 911 pump below, there are many variations with the same theme.
Porsche runs a real dry sump system.
HD could.....they would pick up some real engineers.
Notice the scavage is two-time larger than the pressure side.
How big is it?
More then a large hand full -you can't wrap your finger around it.
The pump not counting the tube depending on which one (many variations as said) is 5 inches to 10 inches long .'
It's very real
Last edited by Kingglide549; Feb 6, 2019 at 10:35 AM.
Seasoned HDF Member
Joined: Jul 2014
Posts: 8,554
Likes: 3,309
From: Cental, MI
^^ That is my point... but, unnecessary if an evacuation pump... even electric is used... or.. Simple thought... use the intake to help in this regard... ala the MoCo method...
Oh Yea... darnnit gonna get oil into the combustion chamber.... Only if something is Not Right anyway!!!!
Especially with a head breather....
BTW There are an abundance of oil pumps out there with Much larger scavenge side than feed, specifically designed for Harley's!!... and we even restrict oil Severely on the feed side..to the point of bypassing up to Half of it... Sometimes Racers are able to provide real World Solutions to Engineering Problems...that apply to All, without re-engineering/ adapting, a 911 pump...for instance...
Oh Yea... darnnit gonna get oil into the combustion chamber.... Only if something is Not Right anyway!!!!
Especially with a head breather....
BTW There are an abundance of oil pumps out there with Much larger scavenge side than feed, specifically designed for Harley's!!... and we even restrict oil Severely on the feed side..to the point of bypassing up to Half of it... Sometimes Racers are able to provide real World Solutions to Engineering Problems...that apply to All, without re-engineering/ adapting, a 911 pump...for instance...
Last edited by Racepres; Feb 6, 2019 at 10:35 AM.
Seasoned HDF Member
Joined: Jul 2014
Posts: 8,554
Likes: 3,309
From: Cental, MI
BTW I like the Dry Sump, as I do not wish for an Oil supply under my engine... Mostly due to the need to then Raise the bike to clear from Harms Way...
The old 4-speed is King of low center of Gravity... The last true Girl's bike IMO... and of course vertically challenged individuals... And... those of us raised on them...
Seasoned HDF Member
Joined: Jul 2014
Posts: 8,554
Likes: 3,309
From: Cental, MI
Back in the day, at the Track, the Shovel guys would Cry sumpin terrible if they had to race against Ironheads... The ones that ever did it before anyway!!!
The dawn of the EVO leveled that a bit...and the Twin Cam is Exceeding even that... Slowly...
BTW Speaking of breathing, and Oil Pumps... The Post '77 Sportster cured alot of that stuff rather handily... Took a while to figure out the Breathing part... but Sporty got it right Long before the Big Twins!!!
Last edited by Racepres; Feb 6, 2019 at 12:07 PM.