Introduction and '73 revival project

[Reuben L]

Looking good Mark. Great to see the motor in its home rather than in the corner of the workshop.
Regards
Reuben

[91133]

Well, it looks like it's having a wee sleep back there (in good company with a 993RS and an M6... not so sure about the Maserati) but things have been happening underneath....just getting the alloy trailing arms sorted out. It turns out 'bolt right in' applies only after a bit of work. ;-)

[91133]

Far too long since an update....and far too slow in recent progress but that's another story...things are moving and looking pretty...




Not quite sure how 'original' this exhaust is!

[frankc]

....just getting the alloy trailing arms sorted out. It turns out 'bolt right in' applies only after a bit of work. ;-)

I was considering using the trailing arms from a '77 in my '73 project since they have the correct sway bar drop link connections. What difficulties did you run into?

[Gearby]

I believe the 323 is the production date. My mfi tag for a late June early July 73 car is 32506791
The 325 is 2 months after yours ie may 1973. I have been trying to work out what the last part of the number represents - mine is an 014 pump for an E. I have a feeling it may be a serial number, in my case the 6791'st 2.4 e pump made but without a lot of other data points it would be hard to prove. In that case yours would be the 2154'st 019 pump made????

I know this is going back a ways, but yes 323, refers to March, 1973. 325 is May,1973. First digit is the year and then the second and third are the month. In the '70's Bosch changed the numbering beginning with January at 21, Feb. at 22, Mar. at 23, and so on all the way through 332 (Dec. 1973). As far as the last 5 digits, there is no way they made 6,791 E pumps in '73. According to what I'm looking at they only made 2,421 1973 911E's, which includes coupes, targas, and sportos. I highly doubt that they made 2154 019 pumps. Perhaps Bosch numbered all the pumps sequentially regardless of type. The font is different on the two numbers, probably when the pump housing went to another area to be built it already had the serial number, and then when the guts were put in, the lower number was stamped in.

[91133]

They absolutely will work and the tech article published in Excellence at the end of the 90's is great but leaves out one really important details - you HAVE to use the late hubs as the early ones (73 etc) will leave the caliper and disc 'out' by about 5mm....a *minor* matter not mentioned anywhere I guess because most folk would grab the arms with hubs attached...I just had a couple of NOS arms lying around w/o hubs attached.

I was considering using the trailing arms from a '77 in my '73 project since they have the correct sway bar drop link connections. What difficulties did you run into?

[91133]

I know this is going back a ways, but yes 323, refers to March, 1973. 325 is May,1973. First digit is the year and then the second and third are the month. In the '70's Bosch changed the numbering beginning with January at 21, Feb. at 22, Mar. at 23, and so on all the way through 332 (Dec. 1973). As far as the last 5 digits, there is no way they made 6,791 E pumps in '73. According to what I'm looking at they only made 2,421 1973 911E's, which includes coupes, targas, and sportos. I highly doubt that they made 2154 019 pumps. Perhaps Bosch numbered all the pumps sequentially regardless of type. The font is different on the two numbers, probably when the pump housing went to another area to be built it already had the serial number, and then when the guts were put in, the lower number was stamped in.

Interesting thoughts. I guess the first point to note is that the pumps in question ran across more than one model year and spares were probably numbered also? As far as the 019 pumps go, Porsche was delivering MFI 2.7 engines into ROW markets into the 1976 MY immediately preceding the 3.0 Carrera. That could make 6000 pumps in total a possibility. Maybe.

Cheers,
Mark

[frankc]

They absolutely will work and the tech article published in Excellence at the end of the 90's is great but leaves out one really important details - you HAVE to use the late hubs as the early ones (73 etc) will leave the caliper and disc 'out' by about 5mm....a *minor* matter not mentioned anywhere I guess because most folk would grab the arms with hubs attached...I just had a couple of NOS arms lying around w/o hubs attached.

Ah yes, I remember reading about this somewhere now that you mention it (was it in this thread?). Unfortunately I have neither the stub axles nor the hubs for the '77 arms, but I do have both from the '73 arms. So now the question is; will the later hubs work with the early stub axles? If not, then I'll have to source both parts. I'll have to check the part numbers in PET.

[Gearby]

of course though as the 1974 model year came along the first number on the pumps would have changed to a four and I would assume that the serial numbers would start over again at 1

Interesting thoughts. I guess the first point to note is that the pumps in question ran across more than one model year and spares were probably numbered also? As far as the 019 pumps go, Porsche was delivering MFI 2.7 engines into ROW markets into the 1976 MY immediately preceding the 3.0 Carrera. That could make 6000 pumps in total a possibility. Maybe.

Cheers,
Mark

[91133]

I would assume that the serial numbers would start over again at 1

A logical assumption indeed but how do we reconcile the very high serial numbers? Either way, the numbering system has its mysteries. :-)