> blush.. maybe I spoke too soon about TR4 rad caps?
> ran out and checked;
> I have two NOS UNIPART radiator caps (I believe for TR4)
> UNIPART GRC 112 (sealed in package) and
A little quick web searching turns up that P/N for TR250 and early TR6. I
believe you'll find it has a shorter "reach" than required for the TR2-early
TR4 radiator. As a result it won't hold pressure in the system. Probably
work for the late TR4 & TR4A radiator though.
> UNIPART GRC 102 (loose)
I believe that should be the 7 lb cap used on early TR4.
> and a STANT cap on my ole TR4 radiator in the corner of the shop.
My local radiator shop supplied a 13psi Stant cap to fit my Triumph Stag.
Since my Mk I Stag uses an unpressurized recovery bottle, it has the extra
seal. I'd guess the same cap will fit late TR4-TR6, but I'm not certain of
that. Unfortunately there's not part number marked on it.
According to TRF, the TR6 switched to a 13# cap in 1973, while the TR4-early
6 used a 7# cap. TR2-3 used a 4#.
FWIW, I ran my TR3A at 7 psi, using a Stant cap that I modified myself to
fit the original radiator neck. However, I did that without an original
heater ... not sure if it would stand the extra pressure or not.
Randall
|