Summer writes:
>All my beliefs are being blown out of the water. Here I have been
>conscientiously using lead additive in my TR-3, and now people on this list
>are telling me I don't need it and plain unleaded gas is fine, and that the
>valves will last for many years.
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No all your beliefs are not blown out of the water. If you have a no or
pre lead head, AND it has had a steady diet of lead at one time, then
enough residual lead remains to lubricate the valves and/or seats. Using
unleaded under these conditions and without prolonged high speed/heavy load
you probably won't see any undue valve seat recession. On rebuild it's
false economy to not replace the exhaust valve seats and exhaust valves
with ones designed to run on unleaded fuel as you WILL have premature
(exhaust) valve and seat wear. If you constantly run your engine to
redline, and floor it all the time, then again you will see accelerated
valve seat recession with a pre-lead head weather it's had lead at one time
or not. As for pinging or knocking mentioned in another thread, it IS
damaging to your engine no matter how slight. Knocking or pinging is an
uncontrolled explosion that puts undesigned stress on the piston crowns,
wrist pins, rod bearings and big end bearings. As for you engine system
check indicators, they are not designed to indicate wear or problems in
those areas and its just a matter of time before something will break or
wear out earlier than an engine operated as designed-
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>OK, let me ask about another possible myth I've been living with. What
>about the warnings that say that I should only use Girling approved brake
>fluid? Can I use any good Dot 3 or Dot 4 fluid?
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Yes it has been discussed before but as listers come and go these will be
brought up again and again. That's how the new people learn, and I for one
don't mind repeating. After all we were all *new* listers once :-}. Those
warnings are valid. If your system is a stock Girling system, that has not
been rebuilt and ready for new fluid, then DO NOT MIX FLUIDS and don't use
Dot 3. Dot 4 Girling fluid is designed for the natural rubber seals in
your system and using Dot 3 WILL damage those seals causing pre-mature
failure. If you have completely rebuilt and flushed the entire system,
then you may chose either Dot 5, or Dot 4, but again, NEVER mix fluids,
most are not compatible, and after all, with the exception of Dot 5
(silicon), these fluids are relatively inexpensive. Why take a chance with
such important systems in your vehicle just to save a few pennys??
Barry Schwartz (San Diego) bschwart@pacbell.net
72 V6 Spitfire (daily driver)
70 GT6+ (when I don't drive the Spit)
70 Spitfire (project)
73 Ford Courier (parts hauler, rain vehicle, getting a V6 soon!)
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