Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 05-28-2021, 08:14 PM   #1
midgetracer
Senior Member
 
midgetracer's Avatar
 
Join Date: May 2010
Location: Bismarck ND
Posts: 1,242
Default Thread size for a Model A spark plug

I purchased a Snap On spark plug tap that is listed as 7/8 18NS. Spark plug tap
Stock #T2818. I needed to clean up threads on a high compression head. The tap appears to be 7/8 18 tpi, but when I tried to clean up the threads, it cut more than I expected and the spark plug would not thread into the hole. I tried it on an old head I had laying around and it did the same thing. purchased it on EBay some time ago, so return is not possible. Any thoughts on what I have and what I need. I measured the tpi and it is 18.
midgetracer is offline   Reply With Quote
 


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 01:39 PM.