I know that there are some shops out there building some really good pumps. how do they do that? I got a spare pump, and want to rebuild it, and do it right and have it put done serious fuel out. does anybody what exactly what those shops do and why we end up paying so much money for theirs? where do they get there parts if they do change ir improve the internals.
injection pump parts
- Thread starter Goose_ss4
- Start date
lotzagoodstuff
Full Access Member
+1 on the parts not being the issue, putting it together and making sure that all the clearances on a high tolerance pump is what makes them perform AND last.
Think of it this way: rebuilding and tuning a carburetor is pretty mindless, and there's nothing very high tolerance about it. Now think about a pump that's making around 2000 psi as opposed to a vacuum driven venturi that can (and will) run when it's pretty out of sorts/worn out. I can rebuild the 780 Holley on my racecar in about an hour with $28 worth of good parts, and if I took it to a shop it would be every bit of $150. Taking into account the complexity, cost of parts, and cost of knowledge (knowledge ain't free), I think $500-600 is worth the price for the heart of your fuel system.
Just my .02
Think of it this way: rebuilding and tuning a carburetor is pretty mindless, and there's nothing very high tolerance about it. Now think about a pump that's making around 2000 psi as opposed to a vacuum driven venturi that can (and will) run when it's pretty out of sorts/worn out. I can rebuild the 780 Holley on my racecar in about an hour with $28 worth of good parts, and if I took it to a shop it would be every bit of $150. Taking into account the complexity, cost of parts, and cost of knowledge (knowledge ain't free), I think $500-600 is worth the price for the heart of your fuel system.
Just my .02
Last edited:
rhkcommander
Full Access Member
You can probably rebuild it yourself but no gauruntee about its reliability/performance. Mel has a pic of the calibration machine that rebuilders use somewhere...
OLDBULL8
Good Morning Ya'll.
$65,000 will get you there close for rebuilding.
MidnightBlade
Shiftin' Smooth
So.........according to what you're saying after they pay off the calibration machine, the price of rebuilds will drop
MidnightBlade
Shiftin' Smooth
From what I understand the inside of the pump is cylinder with a piston. The same as with any piston wall contact one or the other is going to get worn out, so they rehone, or if needed rebore the cylinder and then replace the piston with a new one to match the new bore. The way I understood it is, it's like overhauling an engine on mineature scale
Tis true. There is not a huge amount of science in these pumps. And there is more than one technique you can use to increase fuel output. But despite it's simplicity, and the 100 or so parts that are in it, getting all the parts to work in harmony with each other is a bit of a precise science. The calibration machine saves a ton of time, and allows you to measure things you simply cannot measure when the pump is on an engine. The net net is that by the time you get done doing your own rebuild, tweaking, and mounting and dismounting the pump from your engine to make changes, the time you will have spent as well as the sanity you will have lost will make you regret what you've done. That, and by the time you are done if you should happen to luck out and have it come out perfect, you will be unable to tell others exactly what you did, and you won't be able to really share your method for obtaining what is otherwise unobtainium. Did you ever wonder why there are no real articles on how to hop up a pump anywhere on the internet? It's not because pump builders belong to some secret society sworn to secrecy. It's because each builder knows without the calibration machine, it's totally hit and miss as to having any chance of sucess. Think about it.... you can probably find all the info you need to build an atomic bomb, but you won't find much on how to rebuild a pump. That's just illogical unless the answer is what it is.... there is no way to tell somebody how to do it and have it come out right without the tools yet alone the knowledge.
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I have just ran into stanadyne pump shops that charge insanely high price for a stock rebuild, and after all that they say they cannot increase the fuel. they say it breaks thee contact they have with thee pump manufacturer.
icanfixall
Official GMM hand model
redneckaggie
rebel w/o a cause
damn sure wouldnt try to rebuild one myself what they do is anyones guess, I would assume its got something to do with transfer pressure, max fuel output, and timing curve, now how they do that is anyones guess. I do know that the fuel pressure screw is what made the most difference on my bros dodge, but also what ruined the pump over time.
well you have 2 plungers that compress the fuel in a stock pump now stock they are around .280 inch but you can up their size to .350 in. now you also have the 4 plunger option this will just short of double fuel output now how the pump makes pressure is by compressing the fuel between these plungers. now the 4 plunger one is only avaible to gm products right now because it rotates backwards but with some easy modifacations i can put one in the ford pump.
then the expensive part of modding is the cam. the plungers in the pump that compress fuel ride on a cam think of it like the cam in the motor. this cam can radically change the timing of the motor. this cam actually rotates when the cold start advance is activated advancing the timing much farther forward to keep it running. this cam can be modded to do anything you want the pump to do. back in the day tractor pulling used these cam changes to make tons of torque. also this cam can change how fast the injector fires and how long it will stay open. also how quick it closes, all by the lumps that the plungers ride on to compress the fuel. hope that helped you
but the main thing is finding one of those fancy machines now if you have a spare truck you dont mind doing damage to then build your own but i would not put a pump on a truck you need unless you have access to a fancy flow machine like mel had a pic of. if the pump is off a bit it can cause damage and issues but the other point of the flow machine is to replicate the same thing as parts wear etc. it will change flow and proformance. so in all reality if you want the most out of a pump a company can reman one pump better than another but if they do that the general public says why is bobs pump better than jims and assumes its bad quality.
then the expensive part of modding is the cam. the plungers in the pump that compress fuel ride on a cam think of it like the cam in the motor. this cam can radically change the timing of the motor. this cam actually rotates when the cold start advance is activated advancing the timing much farther forward to keep it running. this cam can be modded to do anything you want the pump to do. back in the day tractor pulling used these cam changes to make tons of torque. also this cam can change how fast the injector fires and how long it will stay open. also how quick it closes, all by the lumps that the plungers ride on to compress the fuel. hope that helped you
but the main thing is finding one of those fancy machines now if you have a spare truck you dont mind doing damage to then build your own but i would not put a pump on a truck you need unless you have access to a fancy flow machine like mel had a pic of. if the pump is off a bit it can cause damage and issues but the other point of the flow machine is to replicate the same thing as parts wear etc. it will change flow and proformance. so in all reality if you want the most out of a pump a company can reman one pump better than another but if they do that the general public says why is bobs pump better than jims and assumes its bad quality.
well you have 2 plungers that compress the fuel in a stock pump now stock they are around .280 inch but you can up their size to .350 in. now you also have the 4 plunger option this will just short of double fuel output now how the pump makes pressure is by compressing the fuel between these plungers. now the 4 plunger one is only avaible to gm products right now because it rotates backwards but with some easy modifacations i can put one in the ford pump.
then the expensive part of modding is the cam. the plungers in the pump that compress fuel ride on a cam think of it like the cam in the motor. this cam can radically change the timing of the motor. this cam actually rotates when the cold start advance is activated advancing the timing much farther forward to keep it running. this cam can be modded to do anything you want the pump to do. back in the day tractor pulling used these cam changes to make tons of torque. also this cam can change how fast the injector fires and how long it will stay open. also how quick it closes, all by the lumps that the plungers ride on to compress the fuel. hope that helped you
but the main thing is finding one of those fancy machines now if you have a spare truck you dont mind doing damage to then build your own but i would not put a pump on a truck you need unless you have access to a fancy flow machine like mel had a pic of. if the pump is off a bit it can cause damage and issues but the other point of the flow machine is to replicate the same thing as parts wear etc. it will change flow and proformance. so in all reality if you want the most out of a pump a company can reman one pump better than another but if they do that the general public says why is bobs pump better than jims and assumes its bad quality.
then the expensive part of modding is the cam. the plungers in the pump that compress fuel ride on a cam think of it like the cam in the motor. this cam can radically change the timing of the motor. this cam actually rotates when the cold start advance is activated advancing the timing much farther forward to keep it running. this cam can be modded to do anything you want the pump to do. back in the day tractor pulling used these cam changes to make tons of torque. also this cam can change how fast the injector fires and how long it will stay open. also how quick it closes, all by the lumps that the plungers ride on to compress the fuel. hope that helped you
but the main thing is finding one of those fancy machines now if you have a spare truck you dont mind doing damage to then build your own but i would not put a pump on a truck you need unless you have access to a fancy flow machine like mel had a pic of. if the pump is off a bit it can cause damage and issues but the other point of the flow machine is to replicate the same thing as parts wear etc. it will change flow and proformance. so in all reality if you want the most out of a pump a company can reman one pump better than another but if they do that the general public says why is bobs pump better than jims and assumes its bad quality.
