Mechanical "oem" dual feed ve.

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bogurt

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Hopped up ve pump in normal position. Cheapo ve core pump in place of ac compressor. Obviously replace oem drive setup with a serpentine pulley. On auxiliary pump.... Alter plunger shaft and position fuel collar to prevent injection pressures and reduce heat. Injection line ports blocked. Hose from shutdown solenoid hole to shutdown solenoid hole on main ve pump. Keep spill port holes stock or block port on aux pump or whatever. Could keep case pressures stock but supply double fuel since double vane pumps. Or spin aux pump faster...etc.. You get the idea. I'm not one of the cool ve guys like kta or jqmile so it might just be a crazy idea. I'm just a cheap skate and couldn't find an electric high pressure pump that I liked.
 
All I can add is that if your turning the 2nd pump with the serp belt, it's going to be running faster then the stock pump since the stock pump runs at 1/2 crankshaft speed.
 
Depends on if pump runs on same serpentine as everything else. I could always run a second belt with different diameter pulley...pump shouldn't have over speed or temperature issues if I alter some doodads so that plunger doesn't plunge...then it's just a vane pump. Still no idea if it would work. I was toying with the idea of how fast I could get a 12mm pump to make power...might play with the cam plate. Again, I'm not even close to an expert. I will be tearing my first pump down tomorrow, I've never had one apart before.
 
Personally I like the idea. I'd take out the camplate rotor rollers etc. Basically everything but the vane pump. Build a block off plate for the head and pump top or just plug up the head accordingly. Use the pulley size to tune for the base pressure you want.
 
P pumps are lame TO ME. Everyone and their grandma can make power easily with a p pump just by bolting stuff on that someone else came up with. There's just no fun in doing something that 100s of other people have already done. There's still plenty of things that haven't been tried with ve pumped motors yet and they are much more fun to tinker with. As far as time to fab....I don't see bolting some stuff up as taking any longer than doing a swap. I have as much fun tuning as I do driving and just throwing money at a p pumped motor with no experimenting needed seems boring to me.
 
I like the idea also. But could you not find a cheap hydrologic pump to do the same with better pressure? Then you would not loose your core ve (they are starting to get hard to find). With the second ve pump all you will net is the worn out vein pumps pressure 60~150ish. I would think you could find a shaft driven hydrologic pump fairly cheap and mount it in the same location with a pulley set up. If I remember right Brian block was doing that back in the day to keep case pressure?
 
bogurt said:
P pumps are lame TO ME. Everyone and their grandma can make power easily with a p pump just by bolting stuff on that someone else came up with. There's just no fun in doing something that 100s of other people have already done. There's still plenty of things that haven't been tried with ve pumped motors yet and they are much more fun to tinker with. As far as time to fab....I don't see bolting some stuff up as taking any longer than doing a swap. I have as much fun tuning as I do driving and just throwing money at a p pumped motor with no experimenting needed seems boring to me.
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I used to say stuff like this, then I built an 800hp daily driver and had more fun than I ever had toying with VE's. they have their place, and if you have more time than money, more power to ya.

that being said. there are some good cheep vane pumps to be had that would replicate what you are doing . If I was you I would shoot for more than stock pressures. as that is what is going to aid fill time. yes, a second pump will help case pressure maintain itself under load... but go bigger
 
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Not a bad idea, and an easy cheap pump to find. I don't think you can remove the whole guts like mentioned as from memory the cam springs pushing against the cam are what holds the shaft in place it might float around on the shaft and the gear could contact the housing. The secondary pump could easily be used to supply high pressure by using something like this-
http://hydraforce.com/Pressure/Pre-html/6-010-1_RV08-20/6-010-1_RV08-20.htm

set at around 200 250 psi and have it feed the other pump. The problem I see with this set up is that you have to be able to still control the timing curve correctly as the orifice matching is designed with piston pump consumption as a design factor, as in vane pump output at given rpm equals piston pump output + orifice return flow (the 2 in the relief and the 1 in the return banjo fitting), if this balance isn't maintained then your timing goes out the window. Also you are now loading the return orifice with 2GPM fuel flow at 3500rpm instead of 1GPM, and the associated effects of that.

Another problem is what do you do with the return fuel from the aux pump? by design the VE only returns a small amount of fuel to tank the rest is circulated to the inlet of the vane pump, if you return it all to tank then you need a lift pump capable of supplying around 130 GPH to ensure that it can keep up at full throttle with an inlet pressure of say 30psi at the vane pump inlet. IMO you don't need an aux pump you need a better way of controlling the pressure at the head and rotor and maintaining timing advance.

I stuffed around with a spread sheet that maps the flows of each pump and the orifice and the resulting case pressure results, it seems pretty close to real life observations. I will post up some graphs when I get a chance if anyone is interested.
 
Had a bit more of a think about it and if you turn the aux pump at 30-40% of engine speed you should still have 1/3 more fuel output from that pump than the main pump piston rotor can pump, this means your delivery lift pump etc doesn't need to be quite as big but will still have more than enough head room to maintain pressure if you use the relief I posted above.

Id be worried about the case pressure in the main pump if it is no longer supplying fuel to the rotor assembly, it could get easily high enough to explode the case at revs above 3000.
Has anyone read the case pressure at full revs on a dual feed set up where the case is blocked from the rotor?
 
Sorry for getting back to this so late. I slowed down on this project upon realization that I have been chasing horsepower that I had all along. Ive also been sulking a little as well. Ive had a 1/4 inch boost leak in my intercooler boot. My turbo outlet elbow also had a slight leak where the vband is. And my fuelling issue was just silly. When I was upgrading to 1/2 hose, I decided to drill and tap the lift pump input to take 1/2 pipe. The entire screen was covered in little plastic or rubber bits causing starvation....No I don't have a fuel guage. As far as the 2nd pump goes...I never even thought about not having the rotor draw fuel. As far as keeping some of the guts in the pump, thats why I mentioned removing the fuel collar and keeping the rotor intact, possibly modifying. As far as too much fuel for the orfice, I am running injectors twice as large as stock. Im sure the problem could still take place while not under load, but at full throttle I would thing things would be ok. I will be getting back to working on this project. For now, I am going to take my time and make sure I have everything functioning properly before I move on. I also considered running aux ve on a toggle...normally, complicating things isn't my style, but I happen to have a spare motor used for driving water pumps that oughta work out nicely. I can also pretty much make it a stand alone unit for experimental purposes.

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