MFI Pump Dyno build- My newest project

[356RS]

Scott, I have a full copy of the BOSCH PED 6 KL.. maintenance and test flow. Covers all 10 pumps from 69 to 73 but not the 2.8 or 3.0RSR. That I would love to have a copy of. Picture of one of the test flow pages for a 2.4T below:

[356RS]

Finished the pulley adapter today and mounted the electric motor to the test stand. Bolted the test stand to the work bench. I will finish the wiring of the motor to variable speed control unit tonight.

[304065]

What is your plan for motor speed control? Variac?

How will you count revolutions for a test?

How will you monitor RPM? Would be cool to use a factory tach modified to take a hall sensor.

This project is OUTSTANDING, thank you for having the courage to tackle it.

When you are finished I'll share my plans for a Bosch distributor machine

[356RS]

John, The speed control is a frequency inverter also a phase-converter to operate a three-phase motor from a single-phase supply. The one I'm using is from "AC Technology Corporation" It's programmable with lots of features like; Independent Accel / decal ramp time; 8 programmable preset speeds; DC injection braking; Speed potentiometer control; Acceleration Boost; ect,ect.
RPM will be counted with a Shimpo Panel Mount Tachometer with an accuracy of 0.01% at all rpm's. Has a 5 digit LED display and reads from 1 rpm to 10,000 rpm. It uses a Photo-Reflective Sensor at 3 to 5 inch. away from the motor shaft. Reflective tape on the shaft.
Counting the revolutions will be with a stopwatch for now. One revolution of the pump operates each injector and of course the same timing, 1,6,2,4,3,5 of the engine. A test at 1000 RPM will take 60 seconds. Tests made above 1000 rpm can be run for 2 min. and then mathematically worked out for different rpm runs. Tests at slow RPM's like 400 work out to 150 seconds, 600 RPM would be 99.6 seconds. I think I'm figuring this out right, but I'm not 100% sure. Looks like it will take 4 hours or more to complete a full test on a good pump.

[356RS]

Installed the electric motor to the test stand and put on the pulley adapter. I will wire up the variable speed control unit tomorrow and test run for vibrations etc.

[356RS]

Got the electric motor running today along with the RPM counter and throttle arm adapter for the angle of degree reading. Hooked up a MFI fuel pump and filter console, set pressure at 1 Bar, filled the boat gas tank with Stoddard Solvent, added the injectors and started pumping. Did a test at 450 RPM then ran it up to 4000 RPM with no problems.

[jbell959]

That is awesome... Congratulations.

[jpahemi]

Mark:

Would there be any benefit to mount the MFI pump body to some type of vibration isolating blocks on the stand?
Great project!

Regards,
jp

[jcge]

Great work Mark - glad to hear you could hit top speed without any problems- did you stay with the 1/2 hp motor? How was the overall rigidity of the setup ?

John

[kenikh]

Mark, you are my hero. This rocks.

[Jandrews]

I love this kind of "take control" approach!! Bravo! This is what makes the Porsche DIY community so amazing!

Let me know if you need another test subject....'73 2.4S MFI pump currently running on 2.7RS motor....you know, just for more data points!

JA

[356RS]

Let me answer some of your questions: JP; Several people have been concerned about the stability of the pump mount, including myself. I used 3/4 inch OD solid round Aluminum stock for the pump mounts on all four corners. Made sure the 2 rear mounts were welded not only at the bottom, but also up the side of the drain bowl. Those two will carry most of the load. Running it today @ 4000 RPM showed just about zero vibration. Very smooth at all speeds.
John; As far as overall rigidity of the pump test stand, it is made up with 3/16 Aluminum and bolted to the table. I can work on the pump, like remove the outer pulley hub and also remove the inside collar nut that secures the space cam & counter weight with no problem. Solid as a rock. Oh, buy the way, It's a 1/3 HP motor. Happy to see it turn the pump so well.
JA; One of my reasons to do all this was so I could change the space cams like on a 72 T pump with a RS space cam and then dial it in to spec. I have 7 MFI pumps from year 69 to 73 I can't wait to check specs on.
And after a few pump tests and fine tuning under my belt, I'll be ready to take on someones pump.

[jcge]

Fantastic work Mark (and the custom glassware looks great too)

I'm sure you'll be needing a bunch of NLA tools (or substitutes) to help set up your pumps...

Here's a few I've built (for taking a micrometer head) - 17mm is the retracted "zero point" on the Mitutoyo spindles that I have.



And for the rack displacement....(thread on right image is M14x1.5 for the MB/RSR threaded rack bush)



I've also found that a cheap cast iron 2" G clamp with a few mods (cut, braze and bush) makes a great dial guage stand (for the baro cell, thermostat) - I'll post a pic if you're interested.

John

[kenikh]

Originally Posted by jcge

Fantastic work Mark (and the custom glassware looks great too)

I'm sure you'll be needing a bunch of NLA tools (or substitutes) to help set up your pumps...

Here's a few I've built (for taking a micrometer head) - 17mm is the retracted "zero point" on the Mitutoyo spindles that I have.



And for the rack displacement....(thread on right image is M14x1.5 for the MB/RSR threaded rack bush)



I've also found that a cheap cast iron 2" G clamp with a few mods (cut, braze and bush) makes a great dial guage stand (for the baro cell, thermostat) - I'll post a pic if you're interested.

John

This just got even better.

[356RS]

John, This is great! This was the missing piece of the puzzle I hadn't had time to figure out. Yes pictures of the tools would be perfect. Thank you so much John.

[jcge]

Sorry to hijack - I'll run a seperate thread for some of the MFI tools I've made (drawings, how to's and explanations for each) and post a link here.

Mark - Are you using a commercial tool to remove the round nut that retains the flyweight assy from the cam?

John

[911st]

Originally Posted by jcge

Sorry to hijack - I'll run a separate thread for some of the MFI tools I've made (drawings, how to's and explanations for each) and post a link here.

Mark - Are you using a commercial tool to remove the round nut that retains the flyweight assy from the cam?

John

I took a socket and ground it down until I had the two tangs needed to remove the nut and access the space cam. Worked great many times!

It would be interesting to develop some type of model or program so custom space cams could be CNC'd to fit a given builder's needs. Would not be complicated for the right person. Basically just a physical map of throttle position by rpm.

I used to run a black felt pen over the space map and go out and run the car at the place I need more fuel. Then take the pump apart. The space cam left tracks where the black was. Then I would bet my hand grinder and file out.

[356RS]

Not a hijack John. All good stuff and good information.
I made some tools for removing the flyweight assembly. The tool on the left is a puller made from an old VW transmission hocky stick. Drilled out a hole and taped it for a long fine thread bolt, works great. The tool on the right is for holding the MFI pulley while I use the modified scoket, below, to remove the collar nut.

[jcge]

Great tools Mark - thanks for sharing

911st - like your idea of using the felt tip pen to record points of contact

[911st]

Originally Posted by jcge

Great tools Mark - thanks for sharing

911st - like your idea of using the felt tip pen to record points of contact

Thx