Laverda
Cast Iron
- Joined
- Mar 24, 2014
- Location
- Riverside County, CA
I am making a part to fit a British carburetor made in the 1940's. I am trying to measure the thread to make the part. The thread is 1 3/4" x 24 TPI. Even with thread gages I can't determine if it is BSF (55 degrees) or CEI (60 degrees). My eyes are not good enough to see a 5 degree difference!
Hours on the internet researching this have only told me what I already know.
Other threads used on the carb are British Association (47.5 degrees), Model Engineers (60 degrees), British Standard Fine (55 degrees) and British Standard Pipe. So they pretty much used everything! Checking with experts on this carb in the UK and they don't know either.
I have never seen a BA thread this big so it has to be either BSF or CEI. Any ideas to determine if it's 55 or 60 degrees without a microscope? I am guessing it's BSF but want to be sure before wasting time on the lathe.
Hours on the internet researching this have only told me what I already know.
Other threads used on the carb are British Association (47.5 degrees), Model Engineers (60 degrees), British Standard Fine (55 degrees) and British Standard Pipe. So they pretty much used everything! Checking with experts on this carb in the UK and they don't know either.
I have never seen a BA thread this big so it has to be either BSF or CEI. Any ideas to determine if it's 55 or 60 degrees without a microscope? I am guessing it's BSF but want to be sure before wasting time on the lathe.