From ‘72T to 2.5 S-R: GeLo Racing #44

[IanM]

I assume they're handed depending whether your car is LHD or RHD?

[matteo68]

All the factory-built SRs were LHD

[IanM]

What's an SR? No mention of that model in any of the Paul Frere's books if I'm not mistaken.

Back in the day, a factory roll cage could be purchased through the race department.

[Nine One One]

Sport / Racing

[Leirbag]

This one? Diagonal going the other way again - same as PET illustration...

Yes, that's the one. Porsche offered the kit for home installation or at the factory, and I feel like the factory installation included the reinforcement in the opposite direction, perhaps to differentiate on a racetrack, both version (M491 and customer) ?

(I doubt they were really focused on aesthetics at that time, but you never know?)

[Leirbag]

Take your pick....

The first 3 on the right : 0910, 0908 et 0870 : factory M491 kit

The other 3 : 911-Kubero (red), 911 030 1016 (white-red) et 911 250 0335 (Kremer green) : either factory kit or own kit

[matteo68]

Sport / Racing

The official term for the 1972 model year was 911 S Coupe M491 Competition or Racing version.

S-R was an unofficial term like ST for the 1970-71 2.3 911 S (which was assembled from various kits which could be ordered from the factory). Because the 21 1972 911 2.5 911 S were developed for Group 4 racing the 'R' for Rennausführung was accordingly adopted in some circles to identify them - this is the fzg-a (or build sheet) for 1687, the last S-R built:




Also the 1973 2.8 RSR was never officially known as that - the official reference was M491 Carrera RS 2.8l - RSR was a term coined by Erwin Kremer, the R for Rennausführung again.

[matteo68]

My 1971-dated "K Kurz Hessental KG" 110l fuel tank came with an original 100l fuel sender and 110mm diameter alu Blau finned fuel cap, all super cool items.



Increasing the cool factor further, I have just learned via another read through of Flunder's excellent / reference ST build thread "Another Hot Rod" on ESR that the Blau cap goes by an early part number for the Carrera 6: 906.201.023.04 "Tank closing"...

[matteo68]

Today's job: turning an original SWF / genuine Porsche washer bottle into an oil breather bottle and trial fitting it in the front-right corner of the engine bay:

Turns out - by reference to the many photos I have of original SR engine bays - that it sits flat on the cross-member so we had to cut the tab off the bottom and the neck off the top and then reprofile the strengthening strip on the top of the cross-member to get it to fit snugly:

[matteo68]

Next we need to fabricate some 90-degree brackets and weld these on to hook the 356 rubber battery strap onto, create a new hole in the shoulder of the bottle for the breather pipe to go into and plug the other two holes

[majordad]

See you at Strahle, we arrive Thursday

[matteo68]

See you there Dave!

I'll have these with me to hawk around the tables!




March'67 dated so all correct for 906 & 911R...

[matteo68]

Bosch transistor ignition modules, ballast resistors and S/121 AA Marelli dizzy - see here: https://auction.nicola-ac.de/catalog134 ... y=&filter= for twin-plug set up...




An NOS set of modules, resistors and coils sold on Ni-Cola for €7,000 4 years ago...

[matteo68]

First job of today: fitting the Bosch push-on / quick disconnect twin CDI cut-off switches (part number: 901.602.702.00) either side of the ignition lock:






(old instruments and alu trim panel mocked up to aid correct positioning)

[Lightweight_911]

First job of today: fitting the Bosch push-on / quick disconnect twin CDI cut-off switches (part number: 901.602.702.00) either side of the ignition lock:

I'm sure you intentionally posted the incorrect part number to see if anyone was watching ...

- that part no.is for the CDI box.

The Bosch 2-pole pull-switches that Porsche originally used for isolating the 2 ignition circuits on the 911R, 904, etc was the same as used in 356/356A models (for fog lights, fuel pump, etc) - part number 644 613 501 01.

This version had the screw terminals but Porsche later (in ~ 1970 from memory) used the version with 'spade' terminals as in your picture (can't remember the Bosch part number offhand).

Apologies for the 'side track' ...

.