MFI injection pumps - alloys used / years

[Rusty911]

I’m curious about when the aluminum mfi housing and aluminum regulators started for the injection pumps and if any other alloys have been used on the pumps. I’ve seen some pumps that appear to be a hybrid with mag housing and al regulator.

Another experienced mechanic said some pumps had cast iron but never heard that before. Does anybody know the types of alloys used for the pumps and when they were used? Any problems with mag on not lasting as long as aluminum or not an issue?

I also saw a side by side comparison of a RS 019 pump and a 2.8 rsr pump. The RS was clearly aluminum but the rsr was much greyer making me think it was possibly mag?

Interested in learning more about this.

[Chuck Miller]

Rusty,

Some info here:
https://www.early911sregistry.org/fo...hat-s-it-worth

[Rusty911]

Thanks Chuck for forwarding link. I did research the threads here and on pelican and just had a few specific questions that might build on those threads.

1. Some threads indicate that around end of 72 (Nov?) is when al pumps started to appear and before that there were hybrid pumps with mag housing and al regulator, I guess I was wondering if there are any clues based on the tags whether a certain serial number range would indicate if pump came as either mag or alum from factory?

2. Besides al and mag, we’re other alloys used for housing like cast iron?

3. Were there any alum 73 rsr injection pumps (RS mostly had alum) or were they mag?

4. Any durability issues with mag housings or mag regulators?

[2.5MFI]

I have a few pumps in house that are alum and with serial numbers starting as low as 229.
Only mag & alum alloys were used on Porsche's. All Mercedes pumps were alum.
All RSR pump were mag. I have seen some alum 3.0 RS Carrera pumps, tagged 019.
The mag pump did have some problems with cracking and threads being striped out.