Looking for period appearing brass knurled thumb nuts that fit the
metric spark plugs of the Z Head. Anyone have a ready source for
The straight side Champion X plugs use #5-40 thumb nuts. I got some #4-40 thumb nuts, drilled them and ran a 5-40 tap through them. The knurl is not quite right, but pretty close. You could probably find some thumb nuts that you could drill out and re-thread for the metric thread.
I'm curious, what plugs are you running?
: ^ )
Let me look at them and post chamarrh. It is midnight and I need to hit the rack.
I can tell you this, I took an original T plug (with knurled thumb nut) and tried the
nut on my modern plug. Threading was slightly off and bound up about 2/3 of the
way down. I then took both plugs to my local hardware store and checked the threads
against their gauge. It came up as 4mm, or "M4".
Well same option applies. Just drill and retap or run some silver solder thru them, drill out and tap M4. They do make metric taps you know.
Or simply chuck some brass rod, bore and tap it, knurl it and groove and part off to suit.
Well, McMaster-carr has them in zinc plated brass, see a bit down on this catalog page: https://www.mcmaster.com/#catalog/123/3230/=182ap3g
If you got to Ebay you can find them in unplated brass from UK but that'll take some more time shipping.
I made my own as a class project, but Keith's suggestion of drilling and retapping would have been cheaper.
Burger, try this place I got mine there years ago.
You can get them right from 'Toms Engine Barn' Directly.
Here is his E-bay store:
Here is another E-bay choice too.
Roger- the nuts you linked to will work but I suspect they are not the profile /look he is seeking.
Chad- the nuts listed @ Toms engine barn are 8/32 thread, just there are "4' of them, but your alternative link is the correct item.