Back in November last year we considered the various sizes and types of pie crust radiator caps found on Armstrong Siddeley cars. From the owner’s point of view having the correct cap, bearing the Sphinx in the correct pose for his or her model of car, is the icing on the cake. This is especially so for anyone fortunate enough to own a Siddeley Special, or indeed for the collector of such memorabilia, it is the prized trophy.
Just when we thought every aspect of these caps had been discussed we received an email pointing out several tell-tale points regarding detail of paws, head dress patterns and the ‘rearing Cobra’ atop the head of the Sphinx. Then an observation so simple, yet so far apparently ignored, concerning the difference between the Special cap and the easy to confuse 20hp cap.
It is this, the pips which form the grip to assist removal of the cap are for the Special 20 in number and those for the 20hp they are 24 in number. Once recognised it is so evident, as seen in the picture below.
We would like to thank those who took the time and trouble to assist us in setting this matter to rights. Your input is appreciated and is exactly the participation this column welcomes.
Footnote. The base of the 12hp cap also has 24 pips but as the Sphinx is noticeably smaller, it rarely causes confusion. Still it is good practice if making a purchase to check out any cap using the measurements provided in the last entry on this subject, 22 November 2022.