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Technical Tips and Discussion by Marvin Mellage
The Four Stages of Model-A Problem Analysis and Resolution
Have you ever experienced strange or new noises coming from you Model-A? And if so, how quickly one goes into stages of problem analysis and resolution? The first stage is, hopefully it will go away and never return again. The second stage is, will doing something a little different reduce or eliminate it. The third stage is, if the noise is here to stay will self diagnosis and repair solve it. And the fourth stage is, who and how many to bring in for problem identification and elimination.
All these phases happened to me not to long ago. I’d been working on someone’s Model-A trying to get it running after eight plus years of barn storage. After doing all the necessary corrections to the fluids, fuel, electrical systems, etc. it was ready. A step on the starter, a pull of the choke, a little gas and the engine came back to life. It sounded real good considering it had been neglected for so long. Then the noises started. There were noticeable cling, bang, clang, ding, etc. noises coming from the motor compartment. I immediately shut it off and got out for a visual engine compartment inspection. Everything seemed okay. Once again I started the engine. Much to my dismay the noises were not only still there, but getting louder and more frequent. A quick acceleration only worsened the problem. Once again I shut the engine off and did another inspection. Only to find everything as it should be. I’m standing there in deep thought wondering what’s broken, what needs to come off, can I fix it? As I was trying to determine what to do next, my wife Linda came into the shop. Now I was faced with concurrent Model-A problem determination and spouse conversation. A tough act for me. Her first words were “what are you doing” and “did you notice”. I nicely stopped her to get focused back on the engine problem. Next after watching me for a minute or so, she interrupted to ask me about the things on the shop floor behind the car. I had not noticed them during my problem determination. Upon further inspection the little blackish, oblong things turned out to be pecans in the shell.
She had identified and helped solve the problem. These pecans were coming out of the exhaust. And the cling, clang, bang, ding noises was their hitting the muffler and exhaust pipe on the way out. After running the engine at different speeds for awhile the noise problem went away. Out of curiosity we picked up the pecans and had two sandwich bags full. Some pack rat had really been busy during the Model-A’s long storage stay.
Through this experience I realized I had successfully gone through the four stages of Model-A problem analysis and resolution.
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Technical Tips and
Discussions by Roy Cail
CAR OVERHEATING or JUST PUMPING WATER OUT or
BOTH??
Did you ever say the
following: My engine continues to overheat.
We have put on a new water pump, the radiator was "cleaned and soldered
and filled", but it still overheats. Not an abnormal thing especially in the Oklahoma summers.
First lets define
overheating.....is it steaming or just pump water out the top.... If it just
pumping water out you may be over filling it....let the radiator find its own
level... each "A" seems to have its own level. As an example, in Kansas City I added water
to our 1929 all the way to the top -- I knew it was too full but it sure looked
good!! When I started the car it
promptly pumped out the excess water until it reached its normal operating
level.
Suggestions:
There are several things that can cause a Model A to overheat. The main cause
is usually the radiator. First you can check to see if your radiator has 3 rows
of tubes. Some of the older replacement radiators had only 2 rows. That will
not provide sufficient cooling. If the radiator is old and has been in the car
a long time, the fins of the radiator become loose and cannot dissipate the
heat. Also, if the radiator is old and has been in the car a long time, calcium
deposits in the radiator will reduce the cooling efficiency of the radiator.
Like many Model A owners
we had to replace a radiator as once we got the car over 40 MPH it would get
hot. The radiator had 3 tubes but only 6
fins per inch (normal) plus the flow rate was quite slow. The new core that was put on has 12 fins per
inch plus they are crinkled to provide
maximum cooling surface area. Replacing
the radiator along with slowing the rate of flow (installed a Thermostat)
stopped the overheating on our "A".
Now let's consider other
potential causes of overheating. First make sure the timing is set correctly.
Then make sure nothing is blocking the front of the radiator, like a license
plate. If you have a new engine, it will sometimes run hot until it is broken
in. There are several books and articles that have been written that will tell
how to correctly set the timing. A blown head gasket can also cause overheating. Check for bubbles in the water at the filler
neck. This may indicate a blown head gasket. Running your car too lean (Gas Adjustment Valve, GAV) can also
contribute to your motor running hot. In
this hot weather there can be many contributing factors.
Technical Tips and Discussion by Roy Cail
Model A Backfiring -- are you kidding??
Question: My Model A is running a little rough with a lot of
backfiring when you step on the accelerator. Can
you give me some idea where to start looking? Ever
ask yourself this question -- I have!! Les Andrews
provides some tips you may want to consider to
eliminate this problem.
Answer:
Back firing is usually caused by the condenser failing
or... the points may not have sufficient gap. Make sure
they are set at .018 to .020”. Make sure they are not
burnt. Backfiring can be caused by intermittent firing
of the ignition system or very lean fuel mixture. If the
car has been setting for a while, the carburetor float
valve may be sticking. Clean the float valve good
and set the float level. Backfiring due to intermittent
ignition can be caused by a frayed wire on the bottom
side of the distributor plate . . or .. by intermittent
connection of the ignition switch.
Potential Solutions:
1) Check point setting first.
2) Replace condenser next (unless you are using
modern points). Make sure the condenser you buy
is the right length, some are too short, and that it is
good quality.
3) Check that the carburetor float valve is operating
correctly.
4) Sometimes the pop out type ignition switches get
intermittent. As a last resort, replace the ignition
switch/cable.
5) Check the GAV to make sure it is not set too lean
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Meeting ScheduleBusiness Meeting - 7:00 p.m.3rd Tuesday of each month at Lewis & Clark Middle School, 737 South Garnett, Tulsa
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