OK its official then.
The NGK Y532J is a dual coil ( self regulating) glow plug rated at 11V ( a little academic in dual coil plugs) and can be used in Wilson switch applications on B engines.
I started my research because I have a B or (1B whatever) with no controller, only a Wilson switch and got through a set of HKT PT145 (10.5V) plugs in less than 5 000 km and with not too many winter starts.
I like the “Full Metal Jacket" and in highly scientific tests carried out by clamping the plugs directly across a fresh battery I got:
15 seconds to full glow with the surviving PT145
6 to 8 seconds to full glow on the Y532J.
Starts like a bastard in 5 centigrade on a 6 second glow ( 1 potato ,2 potato……), and holding them on for a further 6 seconds reduced the exhaust huffing puffing and snot to almost none.
I’m off the west coast of Southern Africa soon, and believe it or not, it gets bloody cold there, so I will report back on my return.
In defence of the HKT plugs I have been having a lot of “hot start” bother where I believed it was necessary to glow the plugs because she struggled to start when hot, so they got more use than normal, and probably a few long glows in frustration at these times. Sorted that problem with an IP rebuild (low internal fuel pump pressure), but still, 15 seconds to full glow and then add another 3 plugs on a not so fresh battery??? thinks.
Anyway, I’ll report back after the trip but see no reason why this “modern technology” can’t be used in the old bangers, but obviously look out for compatibility with glow controllers.