Lucas C45PV Armature

[TCpete (Peter deBruyn)]

Looking for some collective wisdom -
Trying to rehab an early C45PV gennie (production date of 1/36) and find the threads at the end of the armature are buggered. These are an obscure .669-20 (or .668-20) or m17 x 1.27mm - yikes. Anyone have any experience/advice with this? I think I could put a massive chamfer on the end to get the nut started and maybe be OK - but would appreciate others thoughts, thanks.
Pete

[Rob_Reilly]

I believe the thread is 3/8-19 BSPP.

[xk] Generator Pulley

Terry, I measure a major dia of .656" and my 20tpi thread gauge is pretty close, so I figure the thread is 3/8-19 BSPP. Finer than BSF or UNF, probably why they used it. Same as the carb float bowl filter bolts if you want to check me. Rick, You’re right, mine was probably peened by some ham-fisted DPO. John, C2579 (3-7/16" dia.) is listed for Mark V and XK120, C1076 (3-11/16" dia.) is listed for Mark VII. The smaller one would turn faster so would improve the charging at low rpm. Rob…

[TCpete (Peter deBruyn)]

Hi Rob -
Tested the pulley nut on the banjo bolt - BINGO!
3/8 - 19 BSPP it is - thank you so much.
PeTe