flareside_thun
Reviving The General Tao
Geez Mel, that picture brings up not-so-fond memories. I had to tear one apart in diesel class......PITA is an understatement.
pump mods practice and theroy
- Thread starter 88beast
- Start date
phazertwo
Die Summer DIE!
You should speek for your self. I think you would be surprised the number of people on here that know allot more than they let on.
PZ
TestDriver
Registered User
More Pics
Despite DeepRoots's objections, and I can see some of what he objects to, there could be something to learn here. For instance, the discovery of the DB4 rotor was news to me. I'd like to know what the diameter of the DB4 plungers is. It'd be interesting to know the area difference.
I've always thought it'd be easy to increase the DB2 flow in discrete measures merely by varying the plunger diameter. And, since area goes as the diameter/radius squared, it would not take a significant amount to make a measured difference. Could this be the secret of the Alcean pump?
Anyways, here are some pictures I recently took. Some might help in picturing how the pump works.
Uh, sorry. Bin Laden is dead! I'll post pics later after I get myself well sauced over the news. Rejoice!
Despite DeepRoots's objections, and I can see some of what he objects to, there could be something to learn here. For instance, the discovery of the DB4 rotor was news to me. I'd like to know what the diameter of the DB4 plungers is. It'd be interesting to know the area difference.
I've always thought it'd be easy to increase the DB2 flow in discrete measures merely by varying the plunger diameter. And, since area goes as the diameter/radius squared, it would not take a significant amount to make a measured difference. Could this be the secret of the Alcean pump?
Anyways, here are some pictures I recently took. Some might help in picturing how the pump works.
Uh, sorry. Bin Laden is dead! I'll post pics later after I get myself well sauced over the news. Rejoice!
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phazertwo
Die Summer DIE!
DeepRoots
Tug Engineer
My issues are not JUST with the spelling.
Have you ever taken an injector apart and found the theoretical small piston? I only ever remember seeing a spring/seat assembly with shims to adjust pressure. There is also a nozzle. It more resembles a self seating blow off valve than anything.
Wow.... so the lines need to go to specific injectors? No new ground here.
I can't wait for you to teach me some 'mods'
Ok, so is that in or out for more fuel?
or "Adjust it until I see fit"
Mel... I want my money back. (thats sarcasm).
If I came to this board for the first time and I saw this post, and I saw everyone going: "Wow, thanks, that's great."
I would immediately think you were all a bunch of retarded 15 year olds that have never seen a diesel engine. This would have been my last visit to this site.
Best of luck,
Drew
K.... so the fuel system is like a brake system. I guess in as far as they are both hydraulic by nature. So, where is this "Theoretical small piston" in the injector?
Have you ever taken an injector apart and found the theoretical small piston? I only ever remember seeing a spring/seat assembly with shims to adjust pressure. There is also a nozzle. It more resembles a self seating blow off valve than anything.
So does it fire sooner or later? which is it? Ohh, guess it doesn't matter, sometimes you notice it and sometimes you don't. Well, I'm really happy you've cleared that up for me.
Wow.... so the lines need to go to specific injectors? No new ground here.
Oh good, now that you've taught me so much about pump function (ie it's like a brake system, and the lines need to go to their proper injector and need to be the right size I think....),
I can't wait for you to teach me some 'mods'
"Adjust the screw as I see fit" Brilliant! Thanks!
Ok, so is that in or out for more fuel?
Ok, so just f--k with it until it does what I want? Dang, this pump stuff is easy..... I knew Mel was ripping me off with all this "highly refined calibration mumbojumbo" I coulda just dicked around with my pump "till it runs as I wish"
or "Adjust it until I see fit"
Mel... I want my money back. (thats sarcasm).
Nice..... So these two lines are actually the only worthwhile thing said in this post.
If I came to this board for the first time and I saw this post, and I saw everyone going: "Wow, thanks, that's great."
I would immediately think you were all a bunch of retarded 15 year olds that have never seen a diesel engine. This would have been my last visit to this site.
Best of luck,
Drew
flareside_thun
Reviving The General Tao
Wow, I'm glad someone here knows everything about everything and is as perfect as can be in every single way. Without Drew's sarcastic comments I'd sure be lost as a retarded 15 year old and all. If I was new to this site and read this thread I'd be goin, " Oh wow, some people are taking the time to post up decent information and this DeepRoots guy is just being Grade A ****** about it." Ya know, it's nice being reminded that I am a retard by someone such as yourself who obviously has the IQ and anger manageability issues of a chicken. Thanks for clearing that up. I hope my punctuation and spelling didn't mislead you as to the information I've just typed.
Just a reminder guys... keep this level. No personal attacks or name calling. Everybody has an opinion. I think it's naturally curious to want to know more about how these things work, and what a person could do to improve there situation.
No Tom, I don't have any exploded views. There is a web site, and I forget the link, but it has been linked to dozens of times on here that shows you exactly how the parts interact with each other. I'm sure if you search on threads on the DB2 you will find it. Here's the thing, and this is the crux of the problem. Let's say you, me or anybody else here, lets say they come up with some pump that works great. Well, there is no practicle way to duplicate it, because the final result is the end product of tweaking and fooling around with it. You might be able to come up with a recipie for what to do to it, but it's never going to be right, without one of these.
And I think that is the point Drew is trying to make. The amount of man hours and time a person will have invested in trying to come up with something that works well for them is going to make doing it hardly worthwhile. Personally, I don't like swapping pumps in and out of a truck, and I had to do it enough times getting the Moose Pump created, that just doing those swaps was all the effort I could stand. I was glad I didn't have to add on top of that the man hours that went into coming up with the final product that just plain works. And because my guy has this machine, the recipie IS reproducable time and time again. If you took this machine away from him, he would be just as helpless as the rest of us. Probing around in the dark trying to find the light switch.
No Tom, I don't have any exploded views. There is a web site, and I forget the link, but it has been linked to dozens of times on here that shows you exactly how the parts interact with each other. I'm sure if you search on threads on the DB2 you will find it. Here's the thing, and this is the crux of the problem. Let's say you, me or anybody else here, lets say they come up with some pump that works great. Well, there is no practicle way to duplicate it, because the final result is the end product of tweaking and fooling around with it. You might be able to come up with a recipie for what to do to it, but it's never going to be right, without one of these.
You must be registered for see images
And I think that is the point Drew is trying to make. The amount of man hours and time a person will have invested in trying to come up with something that works well for them is going to make doing it hardly worthwhile. Personally, I don't like swapping pumps in and out of a truck, and I had to do it enough times getting the Moose Pump created, that just doing those swaps was all the effort I could stand. I was glad I didn't have to add on top of that the man hours that went into coming up with the final product that just plain works. And because my guy has this machine, the recipie IS reproducable time and time again. If you took this machine away from him, he would be just as helpless as the rest of us. Probing around in the dark trying to find the light switch.
TestDriver
Registered User
Just a reminder guys... keep this level. No personal attacks or name calling. Everybody has an opinion. I think it's naturally curious to want to know more about how these things work, and what a person could do to improve there situation.
No Tom, I don't have any exploded views. There is a web site, and I forget the link, but it has been linked to dozens of times on here that shows you exactly how the parts interact with each other. I'm sure if you search on threads on the DB2 you will find it. Here's the thing, and this is the crux of the problem. Let's say you, me or anybody else here, lets say they come up with some pump that works great. Well, there is no practicle way to duplicate it, because the final result is the end product of tweaking and fooling around with it. You might be able to come up with a recipie for what to do to it, but it's never going to be right, without one of these.
(Pic Deleted)
And I think that is the point Drew is trying to make. The amount of man hours and time a person will have invested in trying to come up with something that works well for them is going to make doing it hardly worthwhile. Personally, I don't like swapping pumps in and out of a truck, and I had to do it enough times getting the Moose Pump created, that just doing those swaps was all the effort I could stand. I was glad I didn't have to add on top of that the man hours that went into coming up with the final product that just plain works. And because my guy has this machine, the recipie IS reproducable time and time again. If you took this machine away from him, he would be just as helpless as the rest of us. Probing around in the dark trying to find the light switch.
You are absolutely right. Without a way to test, there is no means to measure.
I have rebuilt some pumps though. And I'll admit that I have no interest in "modding" them. My involvement comes strictly from doing things for myself instead of paying someone for it. I'd still like to have one of those testers. But, I'm already a card carrying, bona fide tool ****** and have no room for one.
TestDriver
Registered User
Pics
Of the pumps that I've worked on, I've found that the transfer pump is a weak link. Of course, this has been burning WMO. I don't have a good indication as to how the transfer pump would live strictly on D2.
Here are some pictures of how the transfer pump sits on the shaft.
Transfer pump end. The socket head screw is the adjustment for the transfer pump pressure. This screw can be turned in for more pressure if your pump is running low.
Pump vanes and liner. These can be replaced in in situ but it's a bit difficult. The cost is minimal. I think the last time I bought one it was less than $30.
Vanes as they sit on shaft.
Vanes and liner.
Of the pumps that I've worked on, I've found that the transfer pump is a weak link. Of course, this has been burning WMO. I don't have a good indication as to how the transfer pump would live strictly on D2.
Here are some pictures of how the transfer pump sits on the shaft.
Transfer pump end. The socket head screw is the adjustment for the transfer pump pressure. This screw can be turned in for more pressure if your pump is running low.
You must be registered for see images attach
Pump vanes and liner. These can be replaced in in situ but it's a bit difficult. The cost is minimal. I think the last time I bought one it was less than $30.
You must be registered for see images attach
Vanes as they sit on shaft.
You must be registered for see images attach
Vanes and liner.
You must be registered for see images attach
very good pics test. thanks.
Events in a 4-cycle diesel. A little difficult to see, but enlarge it. The post is not about how an IP works, but about what it's function and timing is, timing is very critical to the efficiency of the engine, not so much as the amount of fuel injected. At 2000 RPM, the pump has only 23 thousands of a second duration for the injection process before the piston reaches TDC.
If you want to keep reading about a diesel go here.
http://www.tpub.com/content/construction/14264/css/14264_44.htm
For a mere $35,000 you can purchase a IP pump tester like Mel has pictured.
If you want to keep reading about a diesel go here.
http://www.tpub.com/content/construction/14264/css/14264_44.htm
For a mere $35,000 you can purchase a IP pump tester like Mel has pictured.
Attachments
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DB2 injection operation
The DB2 is an opposed-plunger, inlet-metering, distributor-type diesel injection pump. It was designed for low-cost production and mechanical simplicity. A typical DB2 (there were slight variations on the design for different engines) has a total of approximately 100 components and only four main rotating members. There are no spring-loaded components, none are lap-fitted in manufacture, and there are no ball bearings or gears. The pump has a single pumping chamber in which two opposed plungers are actuated by an internal cam ring.
The geometry of the hydraulic head determined the distribution of fuel between cylinders, and because fuel flow can be preset, lengthy periods spent on the fuel pump test bench were eliminated.
Fuel is drawn from the fuel tank by a mechanical lift pump that works independently of the DB2 injection pump; it passes through two filters and then into the injection pump inlet. From there, fuel flows past the inlet filter screen to the vane-operated transfer pump contained in the pump end cap. The vane-type transfer pump consists of a stationary liner and spring-loaded blades carried in slots at the rear of the transfer pump rotor. As the blades rotate in the liner, they move outward and the volume increases until the leading blade passes out of registry with the inlet slot. The fuel between the blade is carried to the bottom of the transfer pump liner and enters the outlet groove. As a result, pressurized fuel is delivered through the pump into a channel to the hydraulic head passage.
Fuel delivered to the head passage under transfer pump pressure splits in several directions. A portion of the fuel goes to the pressure side of the pressure regulator. The remainder enters a circular passage in the head from which radial passages lead to the vent wire assembly and then to the governor housing and housing pressure regulator; the transfer pressure tap hole plug, which was used for test-stand purposes only; the advance mechanism, and the metering valve.
The pressure regulator assembly in the transfer pump regulates fuel volume based on changes in pump speed--pressure increases with pump speed.
The vent wire assembly is located behind the metering valve bore, and is made up of a J-shaped wire retained in a hollow screw. The wire is free to vibrate and restrict excessive return oil and undue pressure loss.
Fuel entering the housing from the vent fills the housing, lubricates the internal components and cools and carries away any small air bubbles through the return oil line.
The housing pressure regulator is a ballcheck fitting in the governor cover that maintains even housing pressure, except when the housing pressure cold advance solenoid is operating, and allows fuel to return to the fuel tank.
The advance system is a simple, direct-acting hydraulic mechanism. Powered by fuel pressure from the transfer pump, the advance mechanism moves the power piston to rotate the cam to vary the delivery timing. It advances or retards the start of fuel delivery in response to engine speed changes. The advance piston, located in a bore in the housing, engages the cam advance screw and so moves the cam in the direction opposite of rotor rotation. When engine speed decreases, hydraulic pressure is reduced and the cam is retarded because of low transfer pressure. When engine speed increases, transfer pump pressure increases and moves the advance piston and cam.
In addition to the normal speed advance, a mechanical light-load advance is furnished as a function of throttle angle. It consists of a face cam attached to the throttle lever and an external pivot lever. The mechanical light-load advance provides proper advance for light loads when transfer pressure is low and the cam ring is in retard, by changing the reference point of the servo valve.
1981 and later models were also equipped with a housing pressure cold advance solenoid. This consisted of a solenoid assembly in the governor cover, and a ballcheck fitting. The unit allowed more advance at cranking and engine warm-up by reducing housing pressure, which allowed the power piston to move farther (approximately three degrees) in the advance direction. This resulted in a slower, more complete burning of the fuel.
The min-max governor regulates the injection pump at low idle and maximum rated speeds. At speeds between these two ranges, the throttle lever and governor spring of the governor directly control the metering valve.
The governor assembly consists of a cage with flyweights mounted on the rotor and a system of linkages. The movement of the weights acting against the governor thrust sleeve rotates the metering valve by means of the governor arm and linkage hook. The amount of rotation varies the position of the metering valve, thus controlling the amount of fuel to the pumping plunger. The governor derives its energy from the weights pivoting in the weight retainer. Centrifugal force throws the weights outward, moving the thrust sleeve against the governor arm, and rotates the metering valve through a simple positive linkage.
Retention of heat is a critical factor in fuel thinning after a high ambient heat soak. As the hotter, thinner fuel passes through the pump, internal leakage increases, reducing fuel output. To compensate for this loss, a bimetallic temperature compensator strip was added to the governor arm to increase metering valve opening. This provided a compensated idle speed curve and corrected engine idle speed at elevated ambient temperatures.
The metering valve allows a varying amount of fuel to pass through the charging passage to fill the pumping plungers in the distributor rotor. As the rotor revolves, the inlet passage registers with the charging ports in the hydraulic head, allowing fuel to flow into the pumping plunger. With further rotation, the inlet passages move out of registration and the discharge port of the rotor registers with another of the head outlets. While the discharge port is open, the rollers contact the cam lobes and force the plungers together. Fuel trapped between the plungers is then pressurized and delivered through the delivery valve and the nozzle (injector) to the combustion chamber.
More reading go here
The DB2 is an opposed-plunger, inlet-metering, distributor-type diesel injection pump. It was designed for low-cost production and mechanical simplicity. A typical DB2 (there were slight variations on the design for different engines) has a total of approximately 100 components and only four main rotating members. There are no spring-loaded components, none are lap-fitted in manufacture, and there are no ball bearings or gears. The pump has a single pumping chamber in which two opposed plungers are actuated by an internal cam ring.
The geometry of the hydraulic head determined the distribution of fuel between cylinders, and because fuel flow can be preset, lengthy periods spent on the fuel pump test bench were eliminated.
Fuel is drawn from the fuel tank by a mechanical lift pump that works independently of the DB2 injection pump; it passes through two filters and then into the injection pump inlet. From there, fuel flows past the inlet filter screen to the vane-operated transfer pump contained in the pump end cap. The vane-type transfer pump consists of a stationary liner and spring-loaded blades carried in slots at the rear of the transfer pump rotor. As the blades rotate in the liner, they move outward and the volume increases until the leading blade passes out of registry with the inlet slot. The fuel between the blade is carried to the bottom of the transfer pump liner and enters the outlet groove. As a result, pressurized fuel is delivered through the pump into a channel to the hydraulic head passage.
Fuel delivered to the head passage under transfer pump pressure splits in several directions. A portion of the fuel goes to the pressure side of the pressure regulator. The remainder enters a circular passage in the head from which radial passages lead to the vent wire assembly and then to the governor housing and housing pressure regulator; the transfer pressure tap hole plug, which was used for test-stand purposes only; the advance mechanism, and the metering valve.
The pressure regulator assembly in the transfer pump regulates fuel volume based on changes in pump speed--pressure increases with pump speed.
The vent wire assembly is located behind the metering valve bore, and is made up of a J-shaped wire retained in a hollow screw. The wire is free to vibrate and restrict excessive return oil and undue pressure loss.
Fuel entering the housing from the vent fills the housing, lubricates the internal components and cools and carries away any small air bubbles through the return oil line.
The housing pressure regulator is a ballcheck fitting in the governor cover that maintains even housing pressure, except when the housing pressure cold advance solenoid is operating, and allows fuel to return to the fuel tank.
The advance system is a simple, direct-acting hydraulic mechanism. Powered by fuel pressure from the transfer pump, the advance mechanism moves the power piston to rotate the cam to vary the delivery timing. It advances or retards the start of fuel delivery in response to engine speed changes. The advance piston, located in a bore in the housing, engages the cam advance screw and so moves the cam in the direction opposite of rotor rotation. When engine speed decreases, hydraulic pressure is reduced and the cam is retarded because of low transfer pressure. When engine speed increases, transfer pump pressure increases and moves the advance piston and cam.
In addition to the normal speed advance, a mechanical light-load advance is furnished as a function of throttle angle. It consists of a face cam attached to the throttle lever and an external pivot lever. The mechanical light-load advance provides proper advance for light loads when transfer pressure is low and the cam ring is in retard, by changing the reference point of the servo valve.
1981 and later models were also equipped with a housing pressure cold advance solenoid. This consisted of a solenoid assembly in the governor cover, and a ballcheck fitting. The unit allowed more advance at cranking and engine warm-up by reducing housing pressure, which allowed the power piston to move farther (approximately three degrees) in the advance direction. This resulted in a slower, more complete burning of the fuel.
The min-max governor regulates the injection pump at low idle and maximum rated speeds. At speeds between these two ranges, the throttle lever and governor spring of the governor directly control the metering valve.
The governor assembly consists of a cage with flyweights mounted on the rotor and a system of linkages. The movement of the weights acting against the governor thrust sleeve rotates the metering valve by means of the governor arm and linkage hook. The amount of rotation varies the position of the metering valve, thus controlling the amount of fuel to the pumping plunger. The governor derives its energy from the weights pivoting in the weight retainer. Centrifugal force throws the weights outward, moving the thrust sleeve against the governor arm, and rotates the metering valve through a simple positive linkage.
Retention of heat is a critical factor in fuel thinning after a high ambient heat soak. As the hotter, thinner fuel passes through the pump, internal leakage increases, reducing fuel output. To compensate for this loss, a bimetallic temperature compensator strip was added to the governor arm to increase metering valve opening. This provided a compensated idle speed curve and corrected engine idle speed at elevated ambient temperatures.
The metering valve allows a varying amount of fuel to pass through the charging passage to fill the pumping plungers in the distributor rotor. As the rotor revolves, the inlet passage registers with the charging ports in the hydraulic head, allowing fuel to flow into the pumping plunger. With further rotation, the inlet passages move out of registration and the discharge port of the rotor registers with another of the head outlets. While the discharge port is open, the rollers contact the cam lobes and force the plungers together. Fuel trapped between the plungers is then pressurized and delivered through the delivery valve and the nozzle (injector) to the combustion chamber.
More reading go here
TestDriver
Registered User
Transfer Pump Pressure
I forgot to add this. Using an adapter, transfer pressure can be read off the back of the pump. I installed one on a poor running engine and monitored pressure while driving then compared to a rebuilt pump.
The worn pump was running at about 50psi tops and idle went down below 20psi. Cranking pressure was minimal. Starting was a real issue. The rebuilt pump had cranking pressure of about 25psi and top running pressure was around 95psi.
My current pump is running low as well but I've devised a workaround. I tee'd into the line that I have running into the cab to monitor pressure. The tee'd line comes from a typical, high pressure automotive fuel pump. I can run this at startup or if the running pressure is low due to thinning with the throw of a switch. Without it, I'm not sure it would even start now.
I forgot to add this. Using an adapter, transfer pressure can be read off the back of the pump. I installed one on a poor running engine and monitored pressure while driving then compared to a rebuilt pump.
The worn pump was running at about 50psi tops and idle went down below 20psi. Cranking pressure was minimal. Starting was a real issue. The rebuilt pump had cranking pressure of about 25psi and top running pressure was around 95psi.
My current pump is running low as well but I've devised a workaround. I tee'd into the line that I have running into the cab to monitor pressure. The tee'd line comes from a typical, high pressure automotive fuel pump. I can run this at startup or if the running pressure is low due to thinning with the throw of a switch. Without it, I'm not sure it would even start now.
Militaryman445
Full Access Member
I just tried to turn up my pump. Got the cover off and tried turning the motor over. Tried several times, never did that little screw show up. Why do ya'll not have pics of the right spot to adjust this screw? And do you tighten or loosen to increase fuel? Guessing loosen.
