Jeremy DuBois wrote:
>
> Hi all,
>
> I'm having lots of fun playing with my new TR3. Currently I'm
> learning how to get the front apron off the car so I can disassemble the
> overly strange steering system and rebuild it. Anybody know why they didn't
> put rack and pinion on the TR3's? Anybody know if you could fit a TR4
> steering system on a TR3? (No, I wouldn't do it, just was curious if it
> would fit). But anyway, that's not why I'm writing to the list.
>From the look of the factory 'Betas,' and from what Graham Robson says in one
>of
his books, the track of the 4's is wider, so it's likely the rack, with tie
rods
installed, is probably too wide, and to shorten the tie rods would probably
create
a good deal of unwanted bump steer. I imagine it's been done before, but might
also require some fooling with the steering arms, as well.
> I've got an original service manual for my TR3, but I'm beginning to
> find that large portions of it don't make any sense. One of these is the
> section on setting the valve clearances. It tells me to turn the crankshaft
> until the "valves on any cylinder" just begin to "rock", then turn "it" a
> complete revolution to be sure it's in the right place.
> Well, I tried my best to interpret those instructions, but it was
> clear I didn't get them right, as the valves weren't where they were
> supposed to be for me to set them.
What the manuals are saying, I believe, is that in normal engine rotation, the
valves are both open as the piston approaches the top of the exhaust
stroke--i.e., the intake begins to open and the exhaust begins to close--that's
what is meant by "rocking." One more revolution puts the piston near the top
of
the compression stroke, when both valves should be fully closed, with the
lifters
on a portion of the heels of their respective cam lobes.
> Since both the Spit and the TR3 are 4 cylinder
> engines with the same firing order, can I use the Spit instructions with the
> TR3?
You don't supply the method for the Spitfire, but I presume it is something
like,
"when 1&3 are fully open, adjust 6&8," etc. Yes, that will work.
> The other thing I've found is that the original service manual and
> the original owners manual disagree a lot. The service manual says the
> intake valve clearances should be set to .010, and the exhaust to .012,
> whereas the owners manual says both the intake and the exhaust should be
> .010. Anybody know why they'd disagree, and/or which is correct?
They could very well disagree. The factory service manual, because it was used
in
Triumph proprietary shops, was much more likely to be revised promptly, whereas
the owner's manual may have had a lower publication priority. Have a look at
revision dates for both manuals, and see if the service manual's is later. As
for
the settings themselves being different, it's not at all uncommon, since
opening
and closing profiles of the cam lobes are often different, and because the
operating temperature of the exhaust valve is higher than that of the intake,
so
it will tend to grow more. If there's any doubt about settings, use the looser
setting for the exhaust. The more time the exhaust is off its seat, the hotter
it
will get.
Cheers.
--
My other Triumph doesn't run, either....
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