MPS rebuild, mission accomplished Options

[emerygt350]

I just used Chris Foley's excellent rebuild kit on my leaky MPS. After removing the spider webs and varnish it all went together nicely. Chris gave me some great tips on getting an initial set. I think it is there but I don't have any experience with how a well tuned djet 2.0 914 should run. I suspect there is probably 150k or so on this engine although it could be lower, I doubt higher unless it was cared for very very well. Impossible to know with the dead odometer. Compression is great on all cylinders with no variability.

I took a little video of a drive, start up, corners, and two pulls to 60 (of various quality). After the first 40 seconds I opened my sliding rear window so you can hear the engine sounds better.

https://youtu.be/Fi4vFCWhlCw

[emerygt350]

Sorry, I put mm but meant inches. I will fix that.

I am glad someone can use inductance. I found it to be of little value. Certainly my lcr is cheap but I do feel better about tuning it by Dyno and afr.

[emerygt350]

Would be awesome to have a way to check your lcr. Also, that table doesn't seem to do any adjustment for alt. Might just be my phone's browser.

Yeah, just checked it on my laptop. Just didn't like my phone. The readings for alt are only around .01 different for me.

Considering the MPS rebuild is around 200 dollars, buying a 250 dollar LCR could be better spent on buying a good WB02 instead.

[adolimpio]

Would be awesome to have a way to check your lcr. Also, that table doesn't seem to do any adjustment for alt. Might just be my phone's browser.

We honestly don't know if Ander's results are accurate, but we do know that he used a LCR55 so it's best to use the same tool. Others have reported significant differences between it and other meters.

The MPS site should have a field into which you can enter your altitude and then press the submit button. The bottom half of the table should then be adjusted based on the altitude setting.

Also, if the site detects that your device has GPS capabilities you should be prompted to allow access to location services. If you allow it it should display the current altitude in the upper right with a button to use the current altitude. If you press that buttion the current altitude will be copied into the field on the left and then you need to press submit to adjust the table using that value.

[JeffBowlsby]

We honestly don't know if Ander's results are accurate, but we do know that he used a LCR55 so it's best to use the same tool. Others have reported significant differences between it and other meters.

A few of us were around when Brad developed his MPS calibration values, he wporked very methodically. He collected several NOS and otherwise excellet condition orignal, known reliable, MPSs of each part number and characterized each with the LCR55, to generate the values depicted. The values are averages of several MPS values of the same part number, and are as accurate as are available.

With that comes the knowledge we must recognize that different MPS factory original NOS MPS units are not identical calibrations, but are fairly close in range. I can also tell you that an MPS calibration based on 0, 4 and 15 is a good summary and the best informaiont known at the time, but values for 12 and 18 are also valuable and the calibrations for those load conditions are important when using a dyno or WB02 to understand the engine performance over the full range of operating conditions.

Engines and their fueling system must be balanced. You can take a perfectly correct fueling/induction system from one engine and bolt it on another engine and it may not be 100% correct for that engine. The engine itself brings with it variables in wear, compresion/vacuum, and a myriad of other things - so that an MPS calibrated perfectly for one set-up may not be 100% correct for another. It was much easier to do on the production line when everything was new and predicatable, not so much now with the variables in our engines 50 years later.