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"They Wanted a Gold Mine so I
Turned the Shaft"
(Sorry, Jerry
Reed)
or
How to Get More Miles from a Well-Worn Big Healey
Rocker Shaft
by Frank Broome, Gulf Coast Healey Club
This is not for the purist, nor for the faint of heart.
In fact, it may not be for anyone but me. Herein is described a method to
extend the life of a well-worn big Healey rocker shaft assembly many thousands
of miles for less than $10.00. I did this trick to my own BJ8 more than two
years and several thousand miles ago. It worked for me -- and it is
durable.
We all know the eventual problems of wear on this
shaft. low oil pressure, rockers which won’t stay adjusted, oil in the rear
carb, smoking, etc. The simplest (but certainly not the least expensive) cure is
to install a new or rebuilt rocker shaft and bushing kit. But if you are at this
point in your thinking, you might as well give this "quick fix" a try
- you have very little to lose and several dollars to save.
Examine the wear (and the forces which cause the wear)
and you will find it much like a flat tire - only on the bottom.
Three-fourths or more of the shaft looks (and is) like new! And most of the wear
occurs on the shaft, not the bushings. This is understandable because the
original designers, many years ago, had these shafts made from very soft steel -
Rockwell "C" 20 or less. No wonder the shaft wears! So let’s just
turn the shaft over and use that fresh, unworn surface, want to give it a
try? Let’s go!
First, completely disassemble the shaft assembly except
don’t remove the stand with the tapped hole for the banjo fitting. Remove and
clean all parts and lay them out exactly as they come off, so they
can be put back on in the same order. Remove the plug (or plugs) from the shaft
end(s). Note that the shaft is hollow and drilled to center through the
banjo-fitting hole in the stand and that smaller holes are drilled through the
side of the shaft to lubricate each rocker.
Now move the one remaining stand aside far enough to
drill through the opposite side of the shaft, using the existing hole to size
the drill bit and as a guide. A drill press is nice but an electric hand-drill
will work just fine. Through all of this, remember the shaft is very soft, so be
careful not to mar or scratch the surface. You should be able to perform all
operations without resorting to vice or pliers but if such is necessary, grip
the shaft only where a spring goes, never a bearing surface. Remove all burrs
with a fine file before re-assembly is attempted.
OK- Now you have a new hole in what was the bottom
of the shaft. Remove all burrs from in and around the hole and rinse or blow
chips out of the shaft. Now turn the shaft over and slide the stand back into
position with the "new" hole in position under the banjo-fitting hole.
Align carefully! The "old" hole is now blocked by the stand
surface on the bottom. Now that wasn’t hard, was it? But we’re not
done yet.
Look inside one of the rocker bushings. See that
groove? It must line up with the small oil hole in the rocker shaft. But, you
say, these holes are now on the wrong side of the shaft? Not to worry. Just put
the entire assembly back together, exactly as it came apart, except
turn each rocker around so that the groove in the rocker bushing still lines up
with the small oil hole in the shaft. (I know the rockers are now pointing in
the wrong direction - do you think I just fell off a turnip truck? We’ll get
them turned back around in a minute.) Don’t forget to install the plug(s) in the shaft
end(s). So far, so good.
Now, install the assembly on the cylinder head with
the rockers pointing in the right direction. Wasn’t that easy? Everything
lines up just as it-should, right? What - you say the stand with the
banjo-fitting hole is out of position? Drat! Well, let’s do this: with a
fine-tooth hacksaw, carefully cut the small tubing which connects to the
banjo-fitting more-or-less in half. Remove all burrs from both cut ends and
clean each cut end for about one-half inch to bright metal using fine abrasive
paper.
Now is when the $ 10.00 comes in. While your heart rate
and blood pressure are coming down from the trauma of cutting your one-and-only
banjo-fitting tube, drive something other than your big Healey to a nearby
hardware store and pick up two feet of soft 1/4-inch copper tubing and a brass
needle valve (make sure it’s a needle valve) with 1/4-inch compression
fittings. Also pick up a small package of acid-core soft solder.
When you get home, cut the copper tubing about in half
and remove all burrs from the inside and outside of both cut ends. Now slip the
cut ends of your banjo-fitting tubing inside the copper tubing. Isn’t
it neat how it just fits? Now soft-solder each piece into a different piece of
the copper tubing. Not much heat is required - a small propane torch or even a
gas range will do. If you have neither, surely someone in your club does.
Now install the pipe fitting in the head and the banjo-fitting where it goes.
Both just finger tight. Find a convenient place for the needle valve (where it
will clear the rockers, stands and any baffles in the valve cover), cut and fit
the copper tubing to the needle valve and tighten everything securely. Again
make sure everything fits under the valve cover.
What? You say the tubing interferes with one of the
baffles in the valve cover? What can I say? Well, you’ve gone this far so you
might as well take a pair of tin snips, make a couple of cuts in the baffle and
bend the offending piece out of the way. When everything clears, close
the needle valve all the way, adjust the engine valves sufficient for the engine
to run, oil the rocker shaft assembly with an oil can and start the engine.
Adjust the needle valve until oil flows slowly from the hole in the top of each
rocker. Make a final adjustment when the engine has thoroughly warmed up, then
tighten the packing gland nut securely so that engine vibration will not affect
the valve setting, make the final engine valve adjustment, install the valve
cover and it’s all done.
Hope it works as well for you as it has for me. By the
way, this needle valve trick is so slick, I would install one even if I was
using a new rocker shaft and bushing kit - lets you run the engine with the
valve cover off with no mess.
HAPPY HEALEYING!
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