The one no one could fix. 1938 Chevy Master Deluxe Sedan.

One of the Summer 2005 project is to make the ol' Master run. About 39,000 original miles on the clock
(albeit broken) totally original interior, almost no rust, a beautiful car. Several mechanics and who-knows-
how much money later, and there it sat in the garage - going to rust.



Complaint? Recurring stuck valve and bent pushrod, wont start or if it does, poor running and overheating.

The first place I always look is ignition and electrical, because these are the parts that few
are really good at. This ignition system was a wreck, there was little that could go wrong or be done
wrong in this very simple single breaker-point ignition system that wasn't wrong, including grease
having been put between the points faces. Noton the rubbing block, the points faces.

The cotton covered replacement wiring is just like the original? I think the horns are my favorite part of the car.
LOUD!



Unner-neath the valve cover on this straight-6 is the overhead valvetrain. Behind and below the spark
plugs is the pushrod valley covered by a sheet metal cover. Distributor is below the ignition coil.
Hand-made spark plug wires, with non-original orange boots. Steel core wires are the trick.



An extremely experienced and sharp eye can see a problem on the manifolds that needs fixing.
 
Opening up the patient, we get this ugly surprise. Someone left the top end to go to rust.

Theres a potentially engine- destroying problem with this car. On the cowl ahead of the windshield is
an air inlet to the passenger compartment. It has a drain for rain water. That drain discharges directly
onto the back of the valve cover where a stamped opening could allow the water to run into the engine.





Rockertrain rusted, fortunately the material attrition rate is low and this is not a huge problem with cast iron
or steel. The bigger question is," how much rust found its way into the oil pan?" The Carter W-1
carburetor is in the background. Some of the jets were rusted in and could not be removed, fortunately
they work just fine. The tubing and brass connectors behind the coil are part of the low pressure oil
distribution system.



The picture just above is the front of the engine, the one above that is the front-center. The bent pushrod
was #6, right in the area between these two pictures.

Below, the engine block behind the sheet metal cover, rust here, and notice in the above pictures,

NO OIL



Whoever worked on this engine kept blaming the bent push rod on a stuck lifter. I wonder why they were
sticking, maybe because of NO OIL?? The bent pushrod is the one just to the right and touching
the distributor housing. The bend is visible in the photo. The pushrod had a nick right at the bend, so
I wondered if that was a weak spot, or if the pushrod was damaged by other events.

Removed, de-rusted, cleaned and re-lubed rockertrain, freed, de-rusted lifters and a straightened push
rod later, the valve train is back together, with absolute assurance I had not fixed the original problem.
The real problem - why NO OIL???

  The copper tube visible above the distributor is the feed for low pressure motor oil to the top end,
which it wasn't getting. Disassmbly of the oil distributor, hiding behind the exhaust manifold in the third
picture from the top, showed the distributor piston was gummed up and not allowing any oil to the top end.
Everything else in this car that had oil and grease was pretty much gummed up, especially the distributor
shaft whose grease cup contents had turned solid and oil hole plugged.

Below is the low pressure distributor, the check valve was stuck. This engine has 3 oiling systems,
a high pressure pump feed to the crank, a splash to the crank for low speed operation, and a low
pressure forced feed to the top end. Two out of three aren't enough.



12 stuck tappets. An hour with PB Blaster penetrating oil and a hammer freed all 12 lifters.



So, the previous diagnosis - the tappet stuck causing the pushrod to bend.

  Fortunately I knew better, that is impossible unless the pushrod is already damaged.
On top of a bad diagnosis, the previous mechanic did not straighten the pushrod. The tappet
cannot stick in a higher position than the cam normally moves it to, and since that is the normal range of
movement for the pushrod, this cannot cause its damage.

The real problem was hiding in the top end, and was fairly obvious with a casual look. Orange colored
valve guide seals on each and every valve stem. Thing is, they didnt have fancy plastics and rubber
seals and gaskets in 1938. That made the use of valve guide seals unlikely, but left a tough
decision as to whether they should be removed. This decision took about a week, as it is not
one to make lightly, its easy to remove them, but not easy to install a new set. Consulting with a 1930s
text on automotive engineering shed a great deal of doubt as to whether it had them, especially since a
cross- sectional view of this valvetrain did not show seals.

I decided to remove them by just ripping them apart with needlenose pliers. The valve stem and guide
were bone- dry underneath, that was solved by a good soaking with penetrating oil. A dry valve
stem-in-guide certainly would cause a bent pushrod if the valve refused to open, the force would try
to buckle the pushrod.

  The original parts manual for the 1940's Chevy revealed that these engines did not have valve guide
seals until 1941, so that proved they did not belong in the '38. These engines (in a certain range of years)
had either hardened or non-hardened valve guides, the non-hardened apparently need oiling.

Fortunately this car was designed and built tough, it took the abuse well. Well over 100 hours
of work, mostly cleaning and re-lubing, has this engine running like new. Overall, the carburetor
and brakes were the toughest units to repair as they were badly rusted. The brake calipers were
frozen, rusted as is expected. What was not expected was the poor quality repair kits from the
big name parts company that I received - they sold steel caliper pistons and, again, I knew better!
The originals were aluminum, fortunately they weren't steel or the whole works would have been
ruined. The replacements were steel. Steel against steel with moisture is a disaster - itll all rust
together solid and the calipers will be destroyed. The aluminum pistons went back in.

  This machine runs like a top, have had it over 60 m.p.h. and drives great, especially on our modern
roads. The recessed (cold) spark plugs made the fuel system look very rich. Installing a hot set of
Autolite plugs brought the ceramics to clean and white at the stock Carter carburetor settings. 
The thing runs so efficiently (for what it is) that the engine gets cooler as speed increases and it
refuses to overheat no matter how long its idled, which is rare for old vehicles, often they are
seen "overheating in parades."

And, what was the problem hiding in the manifold in the third picture? Tough to see and even tougher
to fix. The manifold runners to/from cylinder # 1 were darker than the rest, indicating a serious air leak.
The intake and exhaust manifolds were leaking terribly - not because of an improper gasket or anything
that simple, it was due to the order of assembly that is needed to properly install these manifolds.

These manifolds should be assembled to the head, to gurantee the gasket is seated correctly, then
both manifolds bolted together below the carburetor. This was not possible as the manifolds are
permanently rusted together. Any attempt to separate them without a machine shop (and Im NOT
about to give these parts to anyone...) would have broken them. I solved the dilemma by making
gaskets from a thick, asbestos head gasket material.

Oh, and of course, the heat riser was rusted shut, which made the engine far too fast to warm up, and
overheat on idle.

Some other pictures for your amusement and amazement...





This one was FUN, trying to repair the ignition switch!



6 volt generator. Charging system emits a perfect 7.24 volts



new plastic gas tank, and boy was THAT fun to R&R! Do you enjoy a face full of rust as much as I?



Li'l starter pieces...



Brakes are nice to have, especially if they work! Nice scare to jack up each front wheel and watch the
fluid leak out of the knee action shocks that someone blew the seals out of with a high pressure
grease gun! NEVER alllow a grease gun on shop air to touch this front end!
It took a month to identify just what to put in the knees for fluid!



Fuel pump with rust donated courtesy the old gas tank



And last, but not least, thanks to Keith Hardy for his on-line repair manuals that were of great help
in putting Humptys Egg back together:  http://chevy.tocmp.com/index.htm