[Healeys] BJ8 radiator cap issue

[Bob Haskell]

Gary,

I take it that David Nock confirmed offline that the GTS1 thermostat 
(shielded wax capsule) he sells opens at 160 degrees.  Could one make a 
180 deg version using a non-sleeved 180 degree thermostat with the 
bypass blanking sleeve (Moss #434-135, BMC 11G176)?  I don't know if the 
groove in the cylinder head is deep enough for both, but there might be. 
  There's suppose to be a gasket under the the thermostat - (which I 
hadn't realized until recently) that might be left out.

Cheers,

Bob Haskell
AHCA 3000 Mk I registrar
http://www.ciahc.org/registry_3000mk1.php

...

> David nock's explanation is based on the assumption that the thermostat is a
> bellows type & the bellows is operating correctly at or below 7 PSI & the
> bellows is collapsing at a pressure somewhere between 7 PSI & 10 PSI. This
> does appear to be a logical assumption/explanation. However, I believe the
> original post indicated that the temperature returned to normal after the 10
> PSI cap was replaced with the 7 PSI cap. I would think that if the brass
> bellows had collapsed it would not function correctly at the lower pressure.
> Replacing the thermostat with the type David describes is the logical next
> step. The only thing I do not like about those thermostats is that they are
> 160 F. Of course, most of our driving is such that the thermostat will be wide
> open & the operating temp will reach equilibrium at some temperature
> independent of the thermostat control temp.
>
> Gary Hodson