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carbs, dead cars, and other stuff

To: british-cars@alliant
Subject: carbs, dead cars, and other stuff
From: muller@Alliant.COM (Jim Muller)
Date: Wed, 22 Nov 89 16:01:59 EST
|Do TR-6s have frames, are are they unibody?

I'm sure some other TR-6 expert here will tell you all you need to know...
For a start, yes, the 6 has a frame (*).  All the "real" TR's (2 through 6)
were built on the same base chassis, though it was upgraded over the years,
especially the IRS addition for the TR-4A.  I'd guess that '69 did have less
emissions stuff, and at some point the cams were softened too.  It may just
be that the softer cam made low-rpm running stronger though.  Likewise, it
is a good bet that the car never got lighter, that its weight was monotonic
with time, though probably not strictly monotonic.  An issue is what other
*improvements* were made though that you might want to get.

(*)  Frames were also used on the Spitfire, GT6, all mammals, and other
higher life forms.


|My source for the Spitfire engine roots came from my Mini Trivia booklet.

Somehow it doesn't surprise me that a Mini Trivia Booklet would describe a
Triumph engine as being designed for a tractor!  (Evil BMC fiend... :-)


About two carbs vs. three, I looked up that passage in C.C.'s book yesterday.
What he actually says is that three carbs will give more power (with specific
reference to Jaguar) but that two is more common for economic reasons.  He
then goes on to describe the problems with each setup.  With an inline-6,
the inner pair's pulsing is indeed symmetric, while the outer pairs' are not.
Since it is found that irregular pulsing gives an average fuel mixture that
is richer than even pulsing, the outer two carb needles need to be slightly
larger than the inner needle to give the same mixture.  (Ever seen that, Joe,
and wondered why?)  For two carbs, each manifold sees uneven pulsing too, but
a reasonable compromise is to place the carbs between the ports for cylinders
2 & 3 and between 4 & 5.  If they are placed in the centers, then cylinders
2 and 5 get too much fuel, and if you offset them to the outside (between 1 &
2 and 5 & 6), the result accentuates any effect of the cylinder on each other.


About using a possibly good car as a parts car, yeah, the concept bothers me
too.  But then you can't save every interesting car all by yourself.  So the
question is:  Is the one you want to take apart ever likely to be set running
again, or will it likely just rust away, being close but always out of reach
of anyone who really cares?  Will your using it make it less likely to ever
be restored?  If you just swap the engine to save cost to yourself, you are
just transferring the cost to the other car, but if it is yours to begin with,
then you haven't done much.  Is it practical for you to keep *both* of them,
possibly rebuilding the other one when finances are not such a problem?  Is
yours more likely to be put back on the road because you sacrificed another
car (which is the inverse of sparing the other at the expense of yours)?
Of course, you could just toss the morality, buy it, call it yours, and do
whatever you wanted with it, if the question didn't matter...which we can
it did, or else it never would have been asked in the first place.

Yours for a higher rationalization...(and higher revs below 60000 rpm),
Jim Muller



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