> When they work, they work very well. When they get a speck of whatever
> in them
> they don't work very well at all.
Fred Thomas was kind enough to volunteer (I did NOT ask) to let me drive his
beautiful TR3A during the 2003 combined VTR/Summer party in PA. It was
fitted with an electric fuel pump, pressure regulator, paper element fuel
filter, nearly new fuel lines, and Grose Jets.
While cruising along at about 50 mph, I suddenly smelled fuel. Pulled over,
and a slick started forming on the wet road (it was also raining at the
time). I tried blowing through the Grose Jet on the offending carb, but it
continued to leak. Fortunately, Fred had thrown the old float valves in the
tool box, so it was a relatively easy matter to put them back (with his
permission, of course).
AFAIK he never replaced the valves again, and never had a problem again. I
don't know what the issue was, but I do know that, with the stock valves, I
would have been back on the road in just a minute or two (undo the nut, turn
the lid over, pull out the pin, turn the lid back over your palm to get the
needle out, wipe the needle with your fingers, reassemble and go), instead
of spending half an hour standing in the rain futzing with a valve that
cannot be disassembled for cleaning or inspection.
On my personal TR3A, I used only the original sediment bowl for a filter and
drove it almost every day for almost 20 years. In all that time, I can
think of only once that I had a float valve problem; and applied the
solution above. I was literally back on the freeway within a couple of
minutes.
Just anecdotes, don't prove anything. But I still think Grose Jets are a
solution in search of a problem, at least for SU H6 carbs. Possibly they
are more effective on other carbs, I don't know.
But every other carbureted vehicle that I've ever owned (GM, Chrysler, Ford,
Audi, White, Yamaha, Honda) has used valves similar to the stock TR3 valves,
and practically every float valve problem I've ever had was due to bad
floats or worn/broken pivots, not a problem with the valve itself. Steel
bearing balls have got to be cheaper in large quantities than those brass
valve needles. If the balls were really better (or even just as good), I
think you'd see at least someone else using them.
-- Randall
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