DIY Kugelfischer Test Stand

[dlacey]

Hey All,

 

During the pandemic I started a project to build a test-rig for Kugelfischer fuel injection pumps, I've got to the point that I can run the tii style pump though its rev range (about 350-3500 rpm pump speed) while ensuring adequate lubricating oil supply and fuel pressure. With this system I can measure the output of the pump at the different throttle lever positions and pump speeds, collecting the injected fuel in simple measuring cylinders. This rig is compact and made just for the tii KF pump, it is not a fully flexible industrial test stand for Bosch diesel pumps and other weird things, just a simple stand to test and calibrate the tii pump.
I asked here a few times to try to get calibration data, seems that data is hard to find...but recently I got hold of the original Schaefer Pump Overhaul and Calibration in German, which explains how to setup the engine-speed-dependent cone position by adjusting the internal spring tension.

 

Here's my contraption:

 

To drive the pump you need a powerful variable-speed motor, I chose a 1000W AC Servo Motor (90ST-M04025) and control its driver using some simple analog wiring. I use a similar drive belt as used by BMW to drive the pump in the tii, with a couple of T5 timing pulleys. 

 

For the oil supply, i used a simple industrial automatic oiler - the type of thing that supplies lubricating oil for equipment... its got quite a low flow but out puts 50-100psi oil, which is perfect for supplying the KF pump... its physically small and easily does the job.
 

 

I mounted the KF pump at the front with the motor underneath for compactness, but the pump drips oil (and potentially fuel), so i fashioned a plate to protect the motor and catch the oil dripping from the KF pump.

For the fuel supply I got a 2 litre Swirl Pot/Surge Tank that the racing boys use, it has a high pressure bosch fuel pump integrated into it. Again its a compact solution to address fuel supply. I was worried that the fuel pump might overwhelm the KF pump, so i fitted a fuel pressure regulator to be able to throttle the output if needed.

 

 

The KF Pump output lines run up to standard DLO20D injectors, which just sit in a 'fuel collector', which is actually just a sintered brass air silencer/muffler... i thought it would minimise the fuel mist and allow the liquid to drain down into plastic measuring cylinders clipped to the plywood back board.

 

 

I'm glad to report that the contraption works fine! 

 

From the Schaefer documents i learnt how to interpret these calibration markings on the 'cone gear' inside the pump:

 

The '0' and '5' refer to the idle speed setting for the cone... 0 is 350 rpm pump speed, and 5 is 500rpm pump speed - these are checked against a datum point on the pump body. These points have no error margin, they must be dead-on correct... if not correct then the large coil spring in the back of the pump is either tensioned or slackened. The manual requires checking for hysteresis, and making sure that '5' mark lines-up perfectly with the datum. Once thats right, pump speed is increased to 1200rpm and the right-arrowed markings above rotate to the datum, and should be within the small band defined by the two marks. Then up to 2800rpm and check the left-arrowed markings against the same datum. If thats all correct then the remaining steps are to set the delivery volume to the specs using the verboten screw.

Hopefully, my translations of the Schaefer documents will get published in the technical articles section of the 02FAQ soon - and that will show how such a test stand can be used to setup these pumps and i can add more detail on what i have found out so far.

 

 

 

 

Edited August 30 by dlacey

[kbmb02]

Great work, @dlacey. -KB

[stephers]

Well done!!        About the sintered mufflers, would you want to see the actual spray pattern as well as the amount?

 

Thanks, Rick

[Mike Self]

Holy cow!  That's a very professional rig!  

 

Think I'll stick with Solexes and Webers 😉...much more my level of engineering!

 

mike

[bob02]

Rube Goldberg would be proud! Very cool, Dave!

 

 Bob

[jimk]

@dlacey ,

Request you add a link to your youtube video on the explanation of the mechanicals of the pump to this thread.  It would add a wealth of information about the pump.

[JsnPpp]

Massive applaud here. Well done! 

[WTP]

Incredible! @dlaceypeople like you are what make FAQ so valuable to the rest of us 2002 owners!

[NMDerek]

great thanks for this too! makes brain surgery easier.

[bergie33]

Dave, that's amazing!  Well done.

[Howardpowered]

love it; looks like some of the rigs i played with in the ChemEng lab. 

 

[gambitpaul]

Very impressive

[SydneyTii]

That’s just very cool!

[resra]

where is Marty Mc Fly? Doc, we are going back to the future!

[dlacey]

18 hours ago, jimk said:

Request you add a link to your youtube video on the explanation of the mechanicals of the pump