I have seen these on model T Fords but nothing here to look at, this I think locks on somehow but do not know how, no threads inside but has tabs on bottom to bend over, anyone know about these? Bob
Ones that I have have an insert with threads. There were a variety of inserts to fit different makes of autos.
The tabs secured this "fitzall" cap to the make-specific insert.
He's asking if the cap is threaded, not how the Motometer is attached.
There are no threads.
The ends of the wire handle clip under the lip of of the radiator neck. You then bend the tabs under the the lip of the neck to prevent the cap from being stolen.
The tabs can break off if the cap is ever completely removed from the neck. That's why many used ones have broken tabs.
Bob, Check Here: http://www.mtfca.com/discus/messages/80257/116084.html
Bob, that is a Boyce model made just for Fords. There was no insert, it's complete as is.
Thank you guys, great to know that, Bob
Robert, the cap is complete. I have had several of them that were NOS. They were prone to have "hairline stress cracks" from the brass probably not being "annealed" after forming. To install it you remove the "bail". There is supposed to be a thin gasket inside the cap that sits on top of the radiator neck and seals the cap to the radiator. You set the cap and gasket on top of the radiator neck and then "re-install the "bail" The "bail and gasket" are what secures the cap to the radiator. The tabs could be bent over for the final fit and security. here is another ad.
A dozen years ago I picked one up off ebay, it was INS as the nickel and the tabs are perfect. Got it at a fair price of 125 today it seams a bit low but was ok then. I have nit yet decided what car to pot it on.