Hi everyone,
I have a 633 big 4, engine no. 3291.
I need a bit of guidance on which valve/guide I need, I have it narrowed down to a couple of options:
Valve ex A2/141 or Valve ex 9120
Valve guide A2/138 or Valve guide 3715
Thanks,
Joe
Big 4 valve/guides
- Log in to post comments
Thanks for your response,…
Thanks for your response, the old valve is sort of in between 5" and 5.2" it's a bit bent but don't think it would straighten to 5.2"....
- Log in to post comments
Hi Joe, I have a 1942ish WD…
Hi Joe,
I have a 1942ish WD Big 4 and believe 5" is correct length for it. New ones I got from Russell Bros. appear identical to my old existing one; bit expensive there compared to NOC shop but got mine when available. Not yet back into engine. Parts numbers inconsistent via various suppliers which doesn't help matters but clarification re email to NOC shop or research with other parts suppliers might clarify. 8932 and 8933 correct re original Norton parts list for guides, and 8934 correct for valve. A2/141 in NOC shop possibly correct but best be sure to save ordering and having to return.
- Log in to post comments
Hi,
NOC shop shows both valve guide part numbers in stock. Looks like 3715 is made to receive grease nipple, (military application?). Valves in NOC shop show 5” and 5.20” lengths. You may need to do some further investigating to determine correct parts. Sorry I’m not familiar enough with these engines to definitively give you a correct answer. I’m curious if it is just civilian/WD as the difference. Hopefully someone with more knowledge can comment. Good luck to you
-Pat