Misc: Ignition Plug Caps

B

BigEd

Well Known and Active Forum User
VOC Member
VOC Forum Moderator
bmetcalf said:
You can get to the Spares site, go to the Forum home page and look in the upper left hand corner.
Click to expand...
A search on the Spares Co website only finds, PR37/2 W/PROOF UNSUPP PLUG COVER so I guess that the screw-type is not available.
 
craig

craig

Well Known and Active Forum User
VOC Member
Who was the manufacturer of these period plug caps?
If Lucas, are these catalog listed?
M039PlugCaps.jpg


BritishSeagullCap.jpg
 
Last edited:
Trickymicky

Trickymicky

Well Known and Active Forum User
VOC Member
I have some originals, and they say Champion on them. The thread in the thumb screws differ though. Some appear to have a 2BA thread, which means that they won't fit the 4mm thread of a modern spark plug. Others were fine.
 
craig

craig

Well Known and Active Forum User
VOC Member
It appears that M4-0.7 and SAE 8-32 threads might be the standard terminal tops for vintage spark plug applications.

PlugThreads1.jpg
 
Last edited:
Trickymicky

Trickymicky

Well Known and Active Forum User
VOC Member
craig said:
It appears that M4-0.7 and SAE 8-32 threads might be the standard terminal tops for vintage spark plug applications.

View attachment 46137
Click to expand...

I've just tried a 2BA screw in mine, and its fine. Looking at terminal thumb nuts available, it seems that there are 3 different threads used - 4mm, 8-32 UNC, and 2BA.

www.gsparkplug.com

4x Spark Plug Brass Thumb Nut 2BA Thread

Buy 4x Spark Plug Brass Thumb Nut 2BA Thread (Spark Plug Nuts / Bullets, Spark Plug Nuts / Bullets) Today. See our great range of Unbranded Products Online Here.
www.gsparkplug.com www.gsparkplug.com
 
vibrac

vibrac

Well Known and Active Forum User
VOC Member
And also those penny pinching swine plugs when the terminal is not a screw but part of the central electrode
 
Top