Leaky Spark, Rusty Cylinder
Walls and Oil Pump Relief
Petulant Flathead
HOWE-TO
Jim Howe
jimhowe@hemmings.com
Q: I have a 1942 Ford Super De Luxe with
an original flathead V- 8 that was rebuilt.
After approximately 20 minutes of running, it sometimes stalls and won’t restart
until it cools for 15 minutes, or unless you
remove a plug
wire and hold it
about 1/6 of an
inch away from
the plug.
I have replaced two
coils, the coil
wire and have
had the distributor rebuilt
and put on a
stroboscope.
I’ve also installed a new
condenser, and
I believe that
we replaced
the coil resistor
under the dash
with a new old
stock piece.
The timing is
correct. I don’t
know if there could be any connection to
the fuel system, but it runs a pair of Strom-
berg 97 carburetors that were fully rebuilt,
and an electric fuel pump in addition to the
rebuilt original fuel pump, with a fuel regu-
lator set at 1½ pounds.
The other day, while cleaning the car
with a damp rag, I got a light shock from
the horn rim on the steering wheel. Do you
think that there is any connection? I have
never been so confused about a car before,
so please advise.
Ray Arnold
Via the Internet
Jim is ready to help solve your
mechanical problems. Just send
your questions to
A: Years ago, I had a very similar experience with a very similar vehicle, a 1948
Ford woodie. The owner would use the
vehicle for a short trip of 30 miles or so,
and it would sometimes begin sputtering
as if it were not getting sufficient fuel.
Sometimes it would actually quit, and
like yours, restart after a few minutes.
Having had a similar problem in terms
of symptoms with a ’ 36 Chevy which
turned out to be occasional fuel starva-
tion due to a piece of RTV floating in the
fuel tank, I chased the fuel system possi-
bilities.
To make a long story longer, it turned
out to be the spark plug wires. On my
vehicle, they were run through steel
tubes along the top of the block, as yours
probably are. As the wires warmed up,
they began leaking spark through to the
steel loom and to each other, creating a
very poor running vehicle.
I suspect the same problem with yours.
My wires looked relatively new and in
good condition, and yours probably do
also—but a new set will straighten out
your old flathead too, I’ll bet.
Trans Am Deep Freeze
Q: I’m trying to un-stick the 400-cu.in.
V- 8 engine in my 1978 Trans Am, which has
not been driven since 1989. I’ve pulled all
the plugs, sprayed Sea Foam “Deep Creep”
into all of the cylinder bores and taken the
belts off of the A/C, alternator and power
steering pump. I’ve been using a deep cycle marine battery to try to turn it over, but
after turning about 90 degrees, it seems to
have stuck, and won’t turn further.
You and others have recommended that
people trying to re-start old 6-volt engines
with 12-volt batteries to add some additional power. What do you think about
sparingly using 24 volts on an old 12-volt
system? I will need to get a new battery for
the car eventually anyway, and it would
be simple to wire it up in series with the
marine battery to get 24 volts. Do you see
any problem with this, other than the obvious concern about overheating the starter
motor?
Steve Free
Via the Internet
A: That 90-degree turn is not a good
sign, Steve.
I had that experience once, and it
turned out that the problem wasn’t that
the engine was actually stuck, but that
rust had formed on the cylinder walls
below the pistons. Thus, as some of the
pistons moved downward, they contacted
the rusty areas and jammed. Evidently,
moisture from the oil evaporated in the
crankcase and condensed on the bare cyl-
inder walls… good reason to change oil
in the fall.
As that engine was not anything we
cared about, except that it run a little
more, I reversed the engine, thus expos-
ing the rust. I was then basically able to
sand the rust off, and the engine turned
freely. This was an inline six-cylinder
engine with plenty of room to work—but
in any event, I wouldn’t recommend this
procedure on anything you cared about!
Big Pressure
Q: I recently purchased a 1970 Chevelle
396/350hp with a four-speed. The car has
been sitting since 1982. I would like to get
it running to be able to move it around
the property while I am doing sheetmetal
work. My problem is that when I got it
started, it blew oil past the oil filter seal. I
replaced the oil filter with a new one, put
in five quarts of new oil, and had the same
problem. I am trying to put off re-doing
the entire engine until after the bodywork
is done.
I noticed that when the car was running,
the oil pressure gauge pinned full pres-
sure, and it goes down to 65 pounds when
it is off. I am thinking about dropping the
oil pan and replacing the oil pump—any
suggestions are greatly appreciated.
John Sammut
Via the Internet
A: I think that you are on the right
track, John.
Chances are good that the relief valve
is stuck in the pump, and if so, they can
build a couple hundred pounds or so of
pressure when cold and at higher RPM.
While on a visit to South Carolina years
ago, I was seduced by a rust-free older
Ford pickup in a junkyard. It looked fine,
but the proprietor said that it had engine
problems and probably needed an oil
pump. I purchased it and had it towed to
my sister’s house, where I discovered a
blown oil filter and warped head.
A call home to junkyard owner John
Cahill confirmed the oil pump theory.
After replacing the pump and head,
I drove it back to Vermont in second
gear—high and reverse were missing. I
saw a lot of things I hadn’t noticed before
during that trip home.
HEMMINGS MOTOR NEWS • NOVEMBER 2009 81
