[TR] TR 4 Valves

[Randall]

> I see from the Moss 
> catalogue that Triumph used different valves for models after 
> CT21470E.  Without pulling the valves (I don't have a spring 
> compressor), is there any way to tell which model engine I have?

I believe you can look between the coils of the exhaust springs, and see whether there is a taper in the stem of the exhaust valves.
The early valves were 5/16" where they go through the retainers and keepers, then swell to 3/8" at the guide.  The later valves are
5/16" for the entire length (and the guides are smaller).

Also, IIRC, the switch to double exhaust springs instead of triple happened at the same time.

But folks sometimes mix & match, so this isn't a sure indication of what engine, only what valves and/or springs.  

Randall