A bleed line from the radiator was rarely used on the MkIs. Don't forget that the Parts List drawing is only applicable to the MkI road cars and is pretty accurate - there were variations as to where the water temperature gauge sensor was fitted and other slight differences; it is obviously only applicable to cars with the Weber set up; the Y-pipe was replaced with a single pipe on the Holley-equipped cars. The race cars generally used a different set up which sometimes included the use of Ricardo gas separators and the larger header tank; MkIIs were different again.I concur, looks like the fan is on the hot input side.
what is not shown in plate D is the radiator air bleed line. This is shown in the Homologation papers or the FSAE papers. Cant remember which one.
Plate D is odd though, it shows the early MK I air bleed tank and heater as was common on the MK I road cars. It also shows the twin hot feed from the 8 stack intake manifold which was not used consistently across all road car. Need to check which way the water pump was configured as well.
It is a method for filling coolant into a closed system originally free of coolant- not a method for removing air pockets from an incompletely filled system. Compressible: watch what the hoses are doing under vacuum (in one of the several u-tube videos on this method) - ;-)How can a vacuum pull air from a non-compressible aluminum radiator if air is sitting at the top of an end tank?
I've drilled and tapped radiator end tanks for a M10x1.0 bleeder, I've done this now on 4 radiators and one heater core. Very satisfying psssst, then coolant to know that just about every mL of air is out of the system!
Dorman 902-112 Coolant Air Bleeder Screw Compatible with Select Models, 2 Pack https://a.co/d/hfeIcUL