Dual Feed P-Pump
Diesel Wrench
Joined: Mar 2007
Posts: 714
Likes: 87
From: York,PA
On a street/daily driver there was no gain seen in the dual feed HP wise at all.
I would disagree with how the ones shown in this thread are set-up.When chatting along time ago with the pump man who did my pumps about this very deal I was told to not feed the pump from the front port,feed it from the OFV port and use the front port as the return with a good regulator to maintain the proper pressure.The reason behind this comment as he then explained to me was cavatation of the fuel inside the pump created by the imbalance of pressure from the front being a straight in feed and the back fuel port having to turn the corner.Naturally the front feed port will try and overcome the rear and could create the cavatation he described to me that day.By using the rear(stock feed port) and the OFV port the fuel will enter the pump in equal amounts and not create as much cavatation inside the pump.By using the front port as the return the overall pressure is maintained more equally thus giving the better balance of fuel distribution to each barrel and plunger.
One thing he stressed back then was that in his opinion this was not needed on a 12mm pump and was better suited for the larger more demanding 13mm pumps.
What needs to be done is for someone to actually put a temp gauge into their fuel line both before the p-pump and after in the return line while running both a single and dual feed set-up.Myself,I do not think there is going to be enough temp difference in the fuel to prove any benefit of the dual feed and I would venture to say you would gain more benefit by adding a cool can to your fuel line and packing it with ice before each pull.
But what do I know as I am just a dumb truck driver.
I would disagree with how the ones shown in this thread are set-up.When chatting along time ago with the pump man who did my pumps about this very deal I was told to not feed the pump from the front port,feed it from the OFV port and use the front port as the return with a good regulator to maintain the proper pressure.The reason behind this comment as he then explained to me was cavatation of the fuel inside the pump created by the imbalance of pressure from the front being a straight in feed and the back fuel port having to turn the corner.Naturally the front feed port will try and overcome the rear and could create the cavatation he described to me that day.By using the rear(stock feed port) and the OFV port the fuel will enter the pump in equal amounts and not create as much cavatation inside the pump.By using the front port as the return the overall pressure is maintained more equally thus giving the better balance of fuel distribution to each barrel and plunger.
One thing he stressed back then was that in his opinion this was not needed on a 12mm pump and was better suited for the larger more demanding 13mm pumps.
What needs to be done is for someone to actually put a temp gauge into their fuel line both before the p-pump and after in the return line while running both a single and dual feed set-up.Myself,I do not think there is going to be enough temp difference in the fuel to prove any benefit of the dual feed and I would venture to say you would gain more benefit by adding a cool can to your fuel line and packing it with ice before each pull.
But what do I know as I am just a dumb truck driver.
Diesel Enthusiast
Joined: Jan 2009
Posts: 144
Likes: 6
From: Morgantown WV
Unless you have a glass pump housing it's just as you said, his opinion. And I've heard the same before. My thoughts after looking at the pump ports was to feed opposite ends and use the rear as a return. With enough volumn and pressure cavitation would be less likely than single fed. This also keeps cool fresh fuel at both ends. If one is enough I have more than I need.
I quit driving otr 15 years ago.
I quit driving otr 15 years ago.
Diesel Bomber
Joined: Oct 2008
Posts: 1,474
Likes: 35
From: Pennsylvania
The only way you could possibly get a pressure differential as you are describing is if there way a restriction to flow such as an orifice. A turn will not do it. Maybe your pump guy needs a lesson in hydraulics.
Diesel Wrench
Joined: Mar 2007
Posts: 714
Likes: 87
From: York,PA
Kevin...
I do not feel its opinion when it comes from someone who has alot more experience than any combination of us here together could ever muster.Feeding opposite ends straight in and the bypass in the center would be the correct and proper way to do it which would then in effect make the fuel feed area in the pump a "fuel Log" in effect.However with no way to make this happen you need to make the best of it and try to ensure that your fuel is fed/enters the same way in both ports.This way when it does bend the corner at the factory feed point its will have the same velocity that the front feed will have.If you feed to pump directly from the front then fuel feed velocities are going to be different due to the difference in feed angles.
Ah Yes Young Mr. Tater....
Lesson in hydraulics you say he needs....
I'd say when that man was in the same world as the rest of us he forgot more than you will ever learn and when we lost him to cancer late last year the local pulling world to a HUGE hit.He was a part of a circle of 4 shops who started this craze we all enjoy some years ago and with his passing,all of the other shops also felt it.So your very vain atempt to make him out to be lacking knowledge does not sit well with me and you need to know who you are flapping your lips about before you flap them.
Old man once told me this and you need to learn it,maybe then your issues will get easier and you may even learn something.....
"Know your role before you flap your hole".
cumminspwr11....
Something like that,but,not exactly......
I do not feel its opinion when it comes from someone who has alot more experience than any combination of us here together could ever muster.Feeding opposite ends straight in and the bypass in the center would be the correct and proper way to do it which would then in effect make the fuel feed area in the pump a "fuel Log" in effect.However with no way to make this happen you need to make the best of it and try to ensure that your fuel is fed/enters the same way in both ports.This way when it does bend the corner at the factory feed point its will have the same velocity that the front feed will have.If you feed to pump directly from the front then fuel feed velocities are going to be different due to the difference in feed angles.
Ah Yes Young Mr. Tater....
Lesson in hydraulics you say he needs....
I'd say when that man was in the same world as the rest of us he forgot more than you will ever learn and when we lost him to cancer late last year the local pulling world to a HUGE hit.He was a part of a circle of 4 shops who started this craze we all enjoy some years ago and with his passing,all of the other shops also felt it.So your very vain atempt to make him out to be lacking knowledge does not sit well with me and you need to know who you are flapping your lips about before you flap them.
Old man once told me this and you need to learn it,maybe then your issues will get easier and you may even learn something.....
"Know your role before you flap your hole".
cumminspwr11....
Something like that,but,not exactly......
Diesel Enthusiast
Joined: Jan 2009
Posts: 144
Likes: 6
From: Morgantown WV
I always listen to and respect my elders. Even though they may not always be right. I've seen many people feed the pump as I do with their explanation why. I had a big paragraph with my explanation but as we all know everyone has their own idea and opinion.
Diesel Fan
Joined: Dec 2008
Posts: 65
Likes: 0
From: socal
ive seen a lot of different set ups, some very big names in diesel motorsports, that run their fuel systems the way Kevin does. i see nothing wrong with it if it has been working for years for them. thats the way i will be doing mine.
Garrett
Garrett
