Hi Dave. The proposed scheme is much
better. In fact, it's EXACTLY what I had in rev-1 (big low
mounted rad, same vent port, etc), and also the way it's done in
a 3rd gen car. Mazda refers to the pressurized can as an
AST (air separator tank). Mine flowed just dandy with and without a
thermostat. The only problem was that it was a pain to fill, since my
pressure cap wasn't the high point.
During my rev-2 upgrade, I simplified the
system further, and got rid of the AST. I was able to mount a
pressurized cap at the high point where
the water outlet is, and only have a plastic jug for overflow
now. So far, this
is working even better.
Ok Rusty, now you have me a little
confused. Your rev-2 upgrade seems a lot like my current system. A
pressure cap (rev-2) at the rear side housing outlet (highest point in the
system) is just like having a small tank there with a pressure cap on it (my
current system). I would prefer not to make the change if you think there
is nothing wrong with the current system and my problem lies elsewhere. To
AST or not to AST, that is the question.
I ran as much as 10 psi on mine, with 9.7
rotors, but I was using 100LL fuel, and had the timing retarded a bit.
From everything I've heard, you won't really be able to tell the diff between
9.0, and 9.7. That being said, when I upgraded my 8.5 rotors, I insisted
on 9.7, rather than the 9.4 rotors. The 8.5's are still in the
attic. They only have Mazda's test run time on them. I'll make you
a good deal :-)
Great data point, Thanks. One vote
for “probably maybe not worth the expense.”
Dave Leonard