Apr 16, 2011
If like me you have lost points during the judging process on your muffler clamps, here is the proper tail pipe clamp installation. The tail pipe clamp was painted black, with a hex bolt, castellated nut and cotter key. Make sure that the tail pipe is correctly clamped to the frame and not over tightened to allow for expansion and contraction. The tail pipe for the 79-B Panel Delivery, the 150-B Station Wagon and the 255-A Special Delivery was made longer and exited to the center or rear of the vehicle. It was fastened to the spring clip bar.
This tech tip was originally printed in the Mar/Apr. 2001 “A” Quail Call.
Apr 9, 2011
If you are humbled when your “A” buddies brag about getting >20 MPG, chin up as 10/15 MPG is about average or about ½ the average of your daily driver. If you are getting less than 10 MPG here are several options:
OPTION 1 – Lie about it! This is very effective if you seldom drive the “A” and acceptable to most gear heads.
OPTION 2 – You should road check your speedometers calibration. Many “A’s” are equipped with 4:11 gears instead of the standard 3:78 ratio. Jack up one wheel, chalk mark the tire and fan pulley and count the engine revolutions to one wheel revolution.
OPTION 3 – Installing the aftermarket air filters reduces mileage by about 1/3, worsening as they become clogged in a few miles. They eliminate dirt contamination but rich mixtures dilute the oil causing excessive wear. The rich mixture is caused by a pressure drop downstream from the filter. Some owners overcome this by using a larger cartridge such as CA3445, and I have seen some install a vent line from a drilled port just ahead of the choke valve to another to the top of the float chamber, plugging the original float chamber vent. This looks OK.
OPTION 4 – Carb jet orifices MUST be to specs (see chart). Most old jets have been opened up by improper cleaning, flow increase horrendously if a few thousandths over spec. Always check new jets before installing.
OPTION 5 – Invest a couple social security checks in an aftermarket overdrive and/or 3:45 gears. The payback in increased gas mileage is about 354 years, reduces RPM from 10 to 30%, less power on hills and reduces braking efficiency.
If all of the above does not work, go back to OPTION 1!
This tech tip was originally provided by Pete Amsler and printed in the June 2000 “A” Quail Call.
Apr 2, 2011
The Model A had a thermo-siphon cooling system. Coolant is not only pumped through the system, but is also circulated by hot water from the engine block forcing the collar water down through the radiator and back into the water jacket in the block. All cooling system components must be in good condition to ensure efficient cooling, but in this article we’ll focus on the radiator.
The Model A radiator consists of a top tank and a bottom tank joined by a series of either round or oval metal tubes, depending on the vehicle and year of manufacture. In operation, the engine-driven water pump supplies water to the top tank which flows through the tubes to the bottom tank and then back to the engine block. Thin sheet metal fins secured to the tubes serve to dissipate the heat of the water flowing through the radiator. The system is open to the atmosphere and is not pressurized.
An overflow pipe is soldered to the radiator frame in two places and extends to the bottom of the radiator. On the ’30-’31 models, there is a hole located in the frame cross-member so that overflow water can fall straight through to the ground. The ’28-’29 models did not have this hole. Some “driving” car builders have added a rubber hose extension to the pipe so that overflow water does not drip on the front spring or axle.
The amount of water that can be pumped through the cooling system is determined by how much water the pump can deliver and how much water can actually flow through the radiator itself. Pump output is dependent on engine speed and under Model A era driving conditions the pump normally did not deliver more water than the radiator could pass. Times change and today’s Model A can be driven at speeds much faster than were envisioned at that time. As a result, it’s possible to pump more water at highway speeds than the radiator can handle. If this happens, the excess water will either flow out the overflow pipe or from under the radiator cap. When you lose enough water, the engine will overheat.
The original Model A radiator could pass from 38 to 43 gallons per minute (flow rate) depending on tube configuration (the ’30-’31 4 row AA Commercial radiator could pass 48 gallons per minute). However, over time, several factors conspire to lower the flow rate:
- Corrosion and mineral deposits inside the tubes.
- Pinched or dented tubes caused by stones or other external factors.
- Damaged tubes removed from service by well meaning, but ignorant, radiator service shops.
Another important, and often overlooked, factor is the replacement of a worn-out or damaged radiator with a reproduction type. In many cases, the “repro” actually has fewer or smaller diameter tubes than the original. It’s no wonder that the flow rate of some “repros” may be less than 30 gallons per minute. A conversation with one reproduction radiator manufacturer revealed that he did not even know the flow rate of his product! For this reason, the Model A owner may be better off restoring the original radiator than installing a reproduction.
A good radiator shop will perform the following steps when rebuilding or repairing an original Model A radiator.
- Measure the flow rate before doing anything else. This can be rechecked later to verify the effectiveness of the repairs.
- Use a caustic solution and ultrasonic equipment to thoroughly clean the tanks and tubes.
- Replace and repair any damaged tubes, maintaining the original number if possible. Extensive radiator damage may require that some tubes be pinched off and soldered closed.
- Reattach loose cooling fins to the tubes. A fin not secured to the tube will not dissipate the heat. In the original radiators, fins were individually soldered to the tubes.
- Lightly paint the radiator with special radiator paint to prevent corrosion. It should be noted that any type of radiator paint or primer will impede heat transfer to the surrounding air but is a necessary evil to protect the radiator.
- Check the flow rate of the refurbished radiator. Remember, a good radiator should be able to pass from 38-43 gallons of water per minute (48 gallons for the ’30-’31 4 row AA Commercial radiator). Any less could be asking for trouble.
Few radiator shops have the equipment or expertise to measure the flow rate and some will maintain that this is not even necessary. Actual experience has proved otherwise and it’s worth the effort to find a shop equipped to do this measurement.
Sometimes a simple back flushing of the engine will clear up an overheating problem. This can be done after the radiator have been thoroughly cleaned. One precaution should be observed if this procedure is used. DO NOT use more than five to seven pounds of pressure or the radiator may be damaged. Original cooling system components were not designed to operate under pressure.
Some controversial consideration…
The following items are considered controversial by some Model A enthusiasts but in my opinion offer some very real and practical advantages:
- Antifreeze coolant – Use of a good antifreeze provides freezing protection if you want to drive your “A” during the winter months. In addition, the built-in rust inhibitor will help keep your cooling system rust and corrosion free. Modern coolants also include a special water pump lubricant, which can extend the life of your pump. In contrast, plain water can promote rust and scale and offers no freeze protection or water pump lubrication.
- Thermostats – Any gasoline engine runs better at a constant temperature because the gasoline vaporizes more evenly. In addition, engines operating at a temperature of at least 165 degrees will evaporate combustion chamber water resulting from the combustion process, helping to prevent rust. A third benefit provided by the thermostat is to act as a “restrictor” at high speeds and reduce the flow rate through the system. This can help prevent water or coolant overflow under highway driving conditions.
Incidentally, if a thermostat is installed, a 1/8 diameter hole should be drilled through the valve plate to allow a small amount of water to circulate through the cooling system at all times. This will ensure that heated water from the block will actually reach the thermostat and cause it to open. If this is not done, the engine may be running hot and the thermostat will not sense the overheating.
More controversy…
If you plan to do a lot of driving at highway speeds, you might consider grinding a little off of the water pump impellor ears to reduce the water flow. This will also reduce flow at lower speeds so it should be done a little at a time. Grind the ears evenly to maintain impellor balance. It would probably be a good idea to check out this procedure with friends or fellow club members before you start!
(Note: Additional information on water overflow and radiator baffles can be found in the April, 1930 Ford Service Bulletins).
This tech tip was originally provided by Walt Wawzyniak and printed in the June 2001 and the August 1992 “A” Quail Call.
Mar 26, 2011
Here is a list of suggested items that should be carried in your “A” at all times. Chances are you will never need them, but you might be glad to have them on hand if necessary.
Electrical tape, cotter pins and lock washers, assorted nuts and bolts, front wheel bearing, valve cores, valve caps, wiper blade, starter drive, starter switch, flares, fine sandpaper, clean rags, magnet, candle, solder wire, repair kit for punctures, engine oil, timing gear, flashlight, bailing wire, headlight and taillight bulbs, radiator hoses, extra water, grease and grease gun, inner tubes, ammeter, coil, carburetor gaskets, distributor, points, “A” crank, wrench, jack, modern tools, cutouts, condenser, spark plugs, air pump, water pump, head gasket, fan, fan belt, radiator cap, gas cap, “Permatex”, insulated wire, tow rope and plastigauge.
This tech tip was originally printed in the May 2000 “A” Quail Call.
Mar 19, 2011
If you hear TAPPING, it could be:
– Incorrectly set valve tappets
– Camshaft bore too large (camshaft too worn)
If you have Vibration in the engine, check:
– Engine not balanced before reassembly
– Flywheel or other “moving” components changed after balancing
– Balanced components not assembled as balanced
– Components not balanced together (static only – not dynamic)
– Dead or dying spark plug/distributor body and/or points
– Ignition; timing incorrectly set (usually too far advanced)
– Carburetor is running too lean
– Intake manifold; intake vacuum leaks anywhere in the intake system
– Fan is either bent or unbalanced blades, not properly “settled” onto taper of water pump shaft, or just plain loose
If you have other Vibration, check:
– Driveline; bent shaft or pinion gear lock nuts loose
– Differential; bad bearings and/or races, pitted or incorrectly set ring pinion, or bent axle shaft
– Transmission; bad bearings, bad gears, bad maindrive gear, and/or frozen pilot bearing in flywheel
– Wheels; extremely out of balance or bent. Loose lug nuts.
– Generator has frozen bearing
– Universal joint; not bolted to mainshaft to transmission, not packed, or just plain too loose
If you are Leaking Oil in the Rear of the engine, check:
– Main bearings too worn or out of tolerance
– Thrust face damaged or worn on rear main
– Gasket between flywheel housing and back of engine block forgotten or damaged
– Oil pan gasket improperly installed or damaged
– Oil return tube on rear main bearing cap missing or its oil return passage is plugged
– Rear main shims improperly installed
– Rear oil slinger improperly installed or missing
– Oil filler cap plugged or sealed
If you are Leaking Oil in the Front of the engine, check:
– Timing cover to crankshaft pulley packing damaged, worn or installed “dry”
– Timing cover gaskets damaged or improperly installed
– Crankshaft pulley excessively worn (you will see a deep groove worn in it)
If you are Leaking Oil in the Side of the engine, check:
– Oil pan gasket damaged or improperly installed
– Oil pan bolts not tight
– Oil return tube gaskets damaged or improperly installed
– Copper compression washers beneath oil return pipe mounting bolts forgotten
– Little pipe plug in side casting adjacent the oil pump forgotten
– “Blow-by” forcing oil out under the filler cap
This tech tip was originally printed in the July 2001 “A” Quail Call.
