Tuning Zenith-Stromberg Carburetors
Since rebuilding my TR2 engine, the carburetors won't tune right anymore.
When I simply bolted things together, they were obviously running lean.
Backing the needle jets all the way down resulted in an almost-but-not-quite
perfect mixture. So it looks like I need either a wider jet, or a narrower
needle. I know that there is a great deal of knowledge on the net about SU
needles & jets... What about Stromberg?
The carbs in question are a pair of 175CD's. They are original for the
engine, which is from a TR4A. The engine rebuild included a bump up from 86mm
to 87, I suppose that affected the mixture.
While I'm on the subject, what is it that's so bad about Z-S carbs? I keep
hearing vague imprecations about them, both on this net, and in other british
car circles. They seem like a nice clean design to me... No remote-mounted
float bowl, no flaky rubber seals to leak between the float bowl and the carb
body, no constantly dripping jet under the carb.. And the principle of
operation is identical to that of the SUs, with the exception of having a true
choke mechanism, instead of a Rube Goldberg machine to raise and lower the
dripping jets :-).
- Jerry
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