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Injection pump ds4

John Romann

Member
Messages
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Location
New york
So this may have been covered before but as it was mentioned in my last post a ds4 can' flow much. So I've been reading my stanadyne operation and instruction manual. Mind you I have never taken a pump apart and being from NYC we don' exactly have alot of pump rebuilders so this is all theory. It appears that inside the pump the transfer section that takes fuel from where most of us enlarge the feed and it goes through a rotary section similar to a rotary engine and on the exhaust side of this rotation is wherre it builds it' pressure as it exits the liner into the rest of the circuit. What is someone was to take the liner and hone it a thousandth or two larger. And enlarge the intake and exit holes a thousandth so it will effectively allow for more volume in this passage without increasing the transfer pressure.20180304_142601.jpg 20180304_142601.jpg 20180304_142601.jpg 20180304_142601.jpg 20180304_142517.jpg
 
The Turbonator brothers (on another forum) tried this and I believe it worked but it scard the walls of the pump after running it a while. I’m pretty sure that’s what happened to it. I do know they said that it cost a whole bunch of money to do it and find a pump builder that would do it and do it right.
 
The Turbonator brothers (on another forum) tried this and I believe it worked but it scard the walls of the pump after running it a while. I’m pretty sure that’s what happened to it. I do know they said that it cost a whole bunch of money to do it and find a pump builder that would do it and do it right.
It shouldn't score the walls. The ds4 manual actually wants you to replace the steel blades with plastic ones so it shouldn't damage a stainless liner unless they had the old blades in there.
 
It shouldn't score the walls. The ds4 manual actually wants you to replace the steel blades with plastic ones so it shouldn't damage a stainless liner unless they had the old blades in there.
And yea my biggest problem is finding a pump rebuilder. I can do the tear down and modifications myself seeing as I have a machine shop next door to my pops shop.
 
That is the internal transfer pump that supplies the plungers and housing pressure for the timing piston.

The cam-ring and the plungers are what dictate the injection size. Then there are pumping losses.
 
That is the internal transfer pump that supplies the plungers and housing pressure for the timing piston.

The cam-ring and the plungers are what dictate the injection size. Then there are pumping losses.
What' The actual name for the plungers. In the entire manual it doesn' mention anything. Ive seen plungers mentioned and their diameter referenced before but I am trying to identify the part in the pump.
 
I miss spoke earlier. I remember what they did now.

They bored it out so they could put bigger plungers in the pump. After it ran for a while it scard the walls up.

Don’t let me discourage you. I’m just pointing out what happened on another build. You might can find someone who understands stanadyne pumps and can do it for you and it not fail like theirs did.
 
I think that is the name. I have only heard them referred to as plungers and seen the word written on internet documents. I am not a pump builder or anything. I did take one apart once and had a look see. I don't exactly know what they are measuring when they say something like 120 mm^3 of fuel per 1000 strokes ????
 
Modifying the vane pump is not likely going to get you anywhere. You can gain a little by switching to the 5068 cam ring, but I hear this is tricky due to a 4° difference in how they are machined. There is also some testing going on with the DS4831-6033 pump which reportedly has a more aggressive cam ring yet.

The plunger removal is shown on page 2.12 of your manual, figure 2.81.
 
Modifying the vane pump is not likely going to get you anywhere. You can gain a little by switching to the 5068 cam ring, but I hear this is tricky due to a 4° difference in how they are machined. There is also some testing going on with the DS4831-6033 pump which reportedly has a more aggressive cam ring yet.

The plunger removal is shown on page 2.12 of your manual, figure 2.81.
Thank you.
 
Thank you.
You're welcome. I have one apart in the shop. If you want photos of anything let me know. Otherwise this site has some threads showing DS4 tear down and assembly. Here are the plungers pulled part way out of the rotor.
 

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You're welcome. I have one apart in the shop. If you want photos of anything let me know. Otherwise this site has some threads showing DS4 tear down and assembly. Here are the plungers pulled part way out of the rotor.
So why would enlarging those 2mm score or lock up anything. And the idea of reworking the transfer section was to move more volume without increasing pressure. Obviously I'd need to modify other sections of the pump to allow the increased volume to travel but that' the feasible way I saw of increasing volume without increasing l.p. pressure or pump pressure stressing components. The manual says the transfer pump is capable of up to 160psi. So if one can move the same volume of fuel at only 120 psi into the next stage then there should be less strain on components
 
Find Kris Stratton on facebook. He's playing around in his spare time with 6.5l pumps, and I believe he hinted at working on a hybrid high flow ds4 pump. I know he is one of the only ones who has posted actual HARD NUMBERS showing what a pump can actually put out, not just the theoretical amount they could flow based on code and bore and stroke of the pump.
 
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