3. Installing front oil coolers and braided crossover lines:
The twin front Behr oil coolers have been one of the biggest challenges with this project, given the ongoing quest for maximum authenticity.
Reference period photos of the luggage compartments for the 18 customer racing S-Rs - 3 more S-Rs were converted to rally spec, these being 0495, 0550 and 1019 - have been extremely difficult to find however this picture of the werks 1972 Monte Carlo rally car 911 230 0041 confirms the factory did use zinc-coated, stainless steel, 32mm diameter, braided oil lines with a consensus opinion suggesting no tracer, as opposed to the hard crossover lines fitted in the 1970-71 2.3 STs:
The serial '72 S hard oil lines running below the passenger door sill (rocker) were omitted due to the high risk of damage on rallies so the flexible braided oil lines were also run inside the car and through the bulkhead into the luggage compartment instead:
No such issues with the racing S-Rs, however, which utilised the serial S hard oil lines although the short serial supply and return connecting hoses (see below)
were replaced with three lengths of the same braided hose (one short section and two longer crossover lines) with M30 x 1.5mm straight and 90 degree Argus fittings attached:
The coolers themselves were the serial '72 S Behr radiator-type cooler with the larger and new for '72 M30 threaded fitting but the brackets were cut off and reversed for the left hand cooler. The serial S cover guard with gasket was employed for RH with a specially fabricated one for LH.
Finding another non-leaking Behr cooler for the LH side to go with @dougieboy1's partially repaired one has been very difficult: a handful of NOS ones are currently available (Manfred Freisinger - €5,000 (of course) and Manfred Herring at Early911.de - a pair for €7,000...
These Behr coolers, whilst light and efficient when intact, are unfortunately very fragile, which might explain why Porsche changed to the more robust (no cover guard required), but less efficient, 'snake' type front cooler for 1973 MY 911 S and Carrera RS.
However I did manage to source another good used one from Dirk Schäfer for €900 whilst at the Strähle swapmeet at the weekend and this will be modified and trial fitted to the shell this week - to go with the right hand one trial fitted yesterday:


Once the left hand one has been installed we then need to mark out where the holes in the inner wings need to be made for the crossover lines to be routed around the rear of the 110l fuel tank. Plastic sleeving will need to be fitted to each hole to protect the braided hose from chafing on sharp steel edges:


(this is the Toad Hall Racing 911 230 0538 following restoration by Porsche Classic and further modifications by Raceline and HS Tuning in Switzerland in 2016 to exact Le Mans 1972 specifications)
More to follow...