[ChrisF]

Thanks for replies. The sets that I bought were straight. I will get a set of finned castings off Les & talk nicely to a friend with a lathe. Threads on the stubs don't look too badly worn. The straight nuts don't even bite & wobble about when on the stubs so are quite a bit larger than the stub.This made me wonder if the head was correct.
Cheers
Chris

[wessex_man]

Could the threads be worn on the head. A set machined to fit may be the best solution.

[singleminded]

Are the nuts for your exhaust finned or straight?
If they are finned you can get the bare castings from the spares shop and if you know someone with a lathe they are fairly easy to machine to size.
here are some that i made..john

[phutton]

Looks like you may have M9 nuts!

P.

[singleminded]

i'm not used to playing with mm..Your stub diameter is only a couple of thou off 2 inches..The nuts you have look like their for  2 1/16th stubs..john

[singleminded]

My 500/600 heads are marked 1722..the stubs are between 51.8 and 52mm. The depth of thread would give in internal on the nut of 50.96..john

[ChrisF]

I am trying to build a 1935 model 8, twin port. I have recently purchased 2 pairs of exhaust nuts for a model 8 but both pairs appear to be a smidge too big. The nuts are 50.96mm diameter inside to the thread but the head stubs are 50.75mm diameter.The head is cast with a number 1823M on the bottom & a letter J. On the top of the head, right hand side, appears a letter L. Can anyone confirm that this is a Model 8 head? The stud holes all line up ok & it fits the barrel & rocker box ok. I was told that the 250 head had smaller exhaust stubs.
Cheers
Chris F