>
> Hi...
>
> My name is Malcolm Walker (I'm borrowing my dad's email account :( ) and
> I've just recently purchased a '62 TR4. I also just recently managed to
> get all the wheels to roll and should be towing it home within a week.
> (whoo!)
>
> Question #1: There's a tube coming out of the valve cover; I suspect that
> I've got a 4A engine in the car. Can I route this tube to any other part
> of the car to increase performance/economy/etc? Should I plug it?
> Should I worry?
Dear Dad...
By now I'm sure you're sick and tired of thinkin you've actually gotten
some sort of important business type email, when in actuality, young
Malcolm has signed you up to a list of loonies with nothing better to do
than fill your in box with British automotive silliness. BUT, if you can
find it in your heart to pass this little epistle on to him, it will
actually save your driveway from the dreaded oil spotting beast.
Malcolm-
It really doesn't matter what the engine really is, but rather, what sort
of crankcase venting it has. The early cars have a system like the 3,
called a "road draught tube". What this is, is a tube of about an inch or
so in diameter, located just to the rear of the fuel pump on the side of
the block. The pipe is inserted in a hole in the block which is baffled,
but open to the crankcase. The tube rises up from the hole a few inches,
then makes a 180 degree turn and ends just below the oil pan. There are no
valves or the like involved. The crankcase vapors are supposed to be
withdrawn from the tube by the slight negative pressure under the car. On
later cars, the hole was sealed with a "bung plug" (always wanted to work
that term into a conversation somehow...). These cars have the little tube
on the valve cover, of which you speak. There are two different types of
systems that utilized the little tube. The first system was merely a "Y"
type connector that allowed the vapors to be split to both air cleaners.
The air cleaners had a matching little tube on their outer metal face that
the hoses connected onto. As far as I can recall there was no valve
involved in this system either. The later system had the hose running from
the valve cover to a valve mounted on a metal stanchion bolted to the
intake manifold. The valve then had a hose which connected directly to a
fitting on the intake manifold.
Care must be taken when dealing with these systems, as mixing and matching
will only result in heart break. If your car has the road draught tube
system on it, it is OK to seal off the fitting on the valve cover. But, if
the car does not have the road draught tube, and you seal the valve cover
tube, you'll think that you have "criminal" oil in your engine, as it will
try to escape out of every hole. This is not good. If your engine has the
bung plug in the hole (wow, twice in one email...), you can remove it and
insert the road draught tube, as that was what your early car probably came
from the factory with. If you are the least bit "green" inclined, the
second system will probably be a step more environmentally friendly, but
messy in the carb department, especially if the motor passes a little oil.
The later TR4 system requires finding all the correct pieces. The little
metal stanchion would be easy to make, but finding an original valve and
fitting could be tough. Also I believe that the fitting was not just an
open hole, but had a restriction in it.
Been accused of creating a "draught" myself...
Nick in Nor Cal
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