Hi,
You asked about heat sheilds for triple Weber setups...
I'm not aware of anyone that sells one, but it would be fairly easy to
fabricate something from some sheet metal. All you need to do is get the
port spacing for the Webers... cut a few holes, line up the mounting
hardware... nevermind. This would be a pain.
;-)
Seriously, all the "sources" tell you to use an airbox of some type.
Theory: cold air is better than hot air. The problem is that there are a
couple of different arrangements with respect to the inner fender well. I
assume you have a stock TR250 inner fender. That being the case, you have
the "harder" of the two inner fender options to deal with. But don't despair.
In short, your airbox should attach to the throats of carbs. Match the port
spacing and you should be okay. Note that with an airbox, you could run one
cone filter instead of the three K&N's or the other options available to you.
But you asked about a heat shield. Ideally, this sould be attached between
the carbs and the intake manifold. Don't make make this too thick, as there
is precious little space between the intake manifold and the carbs and then
the fender well. Also, if you make this piece too thick, it could effect
the "runner length" - and there _might_ be some tuning issues. But
clearance is the big thing.
An easier solution for a lot of folks is either header wrap (which you
asked about) or better still - ceramic coating.
Header wrap is available from Racer Wholesale (1-800-397-7815). The process
of installing the wrap is rather tedious and best done with the header off
the car. A drawback to wrap is that experienced racers indicate that the
wrap leads to premature header failure (rust through and cracks). I have
not seen this, but I see the point.
A better solution is ceramic coating. Figure around $200 more or less. If
the header is used, there is usually an extra cost to boil out the old
header. This needs to be done, because the correct method of ceramic
coating is inside and out of the piece. If you get a cheap quote for the
work, make sure it is clear that you want an inside and out job. This
process will reduce underhood temps and is a very good thing to do, if you
can afford it.
There are lots of places that do ceramic coating now, but the biggies are
Airborne and Swain and also HPC. HPC (I think) has regional vendors, they
have one in Manchester, CT for you New Englanders (I'm pretty sure, but the
general Hartford area) and also Airborne has a depot in that are too. Swain
is in NY state somewhere. At any rate, they're in the Yellow Pages(tm) and
you mail 'em your part and a few days later (well, a week or so) you get
your header back.
Given all the choices, the coating solution would be my first choice
followed by the heat shield.
But you might have another problem. Why is only the center carb hot?? All
the carbs should "feel" the same temp. It might be worthwhile to get some
real data on this. If you know someone with a pyrometer, you should get
actual temps. for the carbs and see if they're within a few degrees. If
not, then you need to investigate. If you don't have access to a pyromter,
you might be able to get a measurement with a meat thermometer... the
problem is that meat thremometers take a while to register temp. whereas
pyrometers measure almost instantly.
At any rate, you should look into the temp. thing first.
FWIW, make sure all the cylinders are running "right". In other words, get
a spark plug reading. You might have a minor carb problem here. If you're
"real adventureous, try swapping the carbs around and see of the "hot spot"
follows the carb.
Either way, good luck.
Aren't WeberZ fun??
rml
=====================================================================
Bob Lang | TR 6 Guy | Editor: New England Triumphs
Phone: | 617-253-7438 (days)| 781-438-2568 (eves)
Occupation: | ComputerZ | TR fixer-Upper
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