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Pricing the Model "A" Ford - Determining the Value and Assigning a Grade - Don Crum, MODEL A TRADER magazine, Vol. 1, No.6, 1991

Tools of the Trade

Pricing a Model A begins with a thorough inspection of the car. The following tools are considered indispensable:

Areas to Inspect

There are four major inspection areas which determine the overall condition of a Model A:

Assigning a Grade

After a complete inspection, the Model A can be graded from 1 to 6 based on the following criteria:

The numerical grade assigned to the car can be translated into an approximate dollar value by checking a price guide such as "Car & Prices" published by Krause Publications, Inc., 700 E. State Street, Iola, WI 54990, 715/445-2214. Cost of this guide is $20.00. Since car prices fluctuate, always check the latest available issue.

The typical values listed in the table below represent average prices compiled during the previous year. Price information is generally derived from auctions and other known sales. Obviously, a given car may be valued higher or lower depending on equipment, accessories, and any special factory options. (Editor's note: Prices shown in the table were valid when this article was first published in 1991. Current prices will differ, but the table is still useful for comparison purposes).

Price Table

No discussion of Model "A" prices would be complete without mentioning the mint condition MARC of Excellence show cars. A car in this category will receive at least 400 judging points at a National Meet and in Don's opinion can be worth an extra $100 for each point over 400. Cars receiving over 450 points frequently command an additional $5,000 or more on top of this amount. The sky is truly the limit, with a few top cars bringing as much as $50,000! (JCY)

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Vehicle Condition Numbers Guide - Author unknown

# 1 Condition - Excellent: Restored to current maximum professional standards of quality in every area, or a perfect original with components operating and appearing as new. A 95-plus point show car that is not driven. In national show judging, a car in No. 1 condition is likely to win top honors in its class. In a sense, it has become an object of art. It is transported to shows in an enclosed trailer and, when not being shown, it is stored in a climate-controlled facility. It is not driven. #1 condition vehicles are very rare.

# 2 Condition - Fine: Well-restored, or a combination of superior restoration and excellent original. Also, an extremely well maintained original showing very minimal wear. Except for the very closest inspection, a #2 vehicle will take the top award in many judged shows, except when squared off against a #1 example in its own class. It may also be driven 800-1,000 miles each year to shows, on tours and simply for pleasure.

# 3 Condition - Very Good: Completely operable original or "older restoration" showing wear. Also, a good amateur restoration, all presentable and serviceable inside and out. Plus, combinations of well-done restoration and good operable components, or a partially restored car with all parts necessary to complete it and/or valuable NOS (New Old Stock) parts. This is a "20-footer." That is, from 20 feet away it may look perfect But as we approach it, we begin to notice that the paint may be getting a little thin in spots from frequent washing and polishing. Looking inside we might detect some wear on the driver's seat, foot pedals and carpeting. The chrome trim, while still quite presentable, may have lost the sharp, mirror-like reflective quality it had when new. All systems and equipment on the car are in good operating order. In general, most of the vehicles seen at car shows are #3s.

#4 Condition - Good: A driveable vehicle needing no, or only minor work to be functional. Also, a deteriorated restoration or a very poor amateur restoration. All components may need restoration to be "excellent, " but the car is mostly usable as is. This is a driver. It may be in the process of restoration or its owner may have big plans, but even from 20 feet away, there is no doubt that it needs a lot of help.

#5 Condition - Restorable: Needs complete restoration of body, chassis and interior. May or may not be running, but isn't weathered, wrecked and/or stripped to the point of being useful only for parts. This car needs everything. It may not be operable, but it is essentially all there and has only minor surface rust, if any rust at all. While presenting a real challenge to the restorer, it won't have him doing a lot of chasing for missing parts.

#6 Condition - Parts Car: May or may not be running, but is weathered, wrecked and/or stripped to the point of being useful primarily for parts only. This is an incomplete or greatly deteriorated, perhaps rusty, vehicle that has value only as a parts donor for other restoration projects.

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A Higher Compression Head For the Model "A" - Better Performance But How Much Is Enough (Larry Brumfield, January/February 1994)

From the letters I receive, people seem to be confused about high compression and the Model "A" Ford. We call the head that we manufacture "High Compression" but that is really a misnomer. It is actually just higher compression. Ford made the Model "A" a low compression engine for maintenance reasons. Let me explain.

In an engine that is operating in a normal manner, the ignition flame consumes the charge at a steady rate of about 100 feet per second until the charge is consumed. However, if the first part of the charge burns in a normal manner and the last part burns almost instantaneously, an excessive momentary pressure unbalance is created in the combustion chamber. This abnormal combustion is called detonation and engine efficiency is decreased. If detonation is severe, structural damage can occur to the piston and cylinder head. This can be a real problem in aircraft engines because the audible knock cannot be heard over the rest of the other sounds.

After many miles of driving and excessive carbon build-up, detonation would be a problem especially with old time gasoline. Ford avoided the problem by making the compression ratio low but still high enough to give the engine "pep. " He knew that the average person was not a mechanic. However, with modern gasoline a higher compression ratio is no problem. In fact, most of the automobiles of the Model "A" era had ratios of about 5.5 to 6 to 1.

Nevertheless, more compression does mean more pressure on bearings. We have experimented with various ratios and we have determined that ratios of 6.5 to 1 and greater tend to be hard on stock babbitt bearings. An engine bored .125 over is still less than a 6.5 to 1 compression ratio with our head. During one of our tests, we held the accelerator on the floor in second gear until the engine was "screaming. " Upon disassembly, inspection revealed no damage to the bearings. We don't recommend this procedure to our customers and since we have no control over the condition of their engines we cannot make any guarantees. But we can honestly say that we have had no complaints. After one of our other tests, inspection revealed that the babbitt began to flatten at ratios of 7 to 1 on a hard run. Unless a person has gone to the expense of modern bearings, they are asking for trouble with extremely high ratios. (Or they have more money than brains!)

Higher compression can also mean better cooling. It is true that the higher the compression ratio, the higher the combustion chamber temperature. But by comparison between two alike engines with different compression ratios, the higher compression one will tend to run cooler. The high compression delivers more of the energy of the fuel as power and less for heat. Consequently, it will run cooler at the same speed and load. We conducted an experiment on a High Country Tour in Colorado in 1979. At high altitude, the boiling point of water is lower. On a steep grade, our Model "A" never lost a drop while the rest were losing water with a steady trail behind them. We passed them in high gear with smiles on our faces!

In conclusion, once you experience the difference that our high compression head makes, to go back to a stock one would be like going back to a burnt valve or running on three cylinders when you can have four!

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MAL Contented! - Common Sense Tricks to Get That Old Engine Up and Running (Fred H. Engelman, Spring 1994)

Last year, three of us here in Alabama happened to get together in conversation and found we had a common love of "Henry's Lady." At the time I owned a 1930 Standard 5 window Coupe and my one friend owned a 1928 Fordor Leatherback. Both of us had some minor problems with our cars but nothing serious. In our conversation, we found that our third party was also a Model "A" lover and he told us that he was probably the best Model "A" mechanic in North Alabama. We were, needless-to-say, quite dubious but we decided to test him. What a find we made because he was more than we bargained for and we were on our way to better motoring.

My friend with the Fordor was in the process of restoring his car from the ground up. He had orchestrated a masterful cosmetic restoration but mechanically it was a mess. Our mechanic friend straightened this right out and did a few more things to boot. The car is now in the process of being upholstered and covered by a professional and it will be a showpiece when it is finished.

My little Coupe is an original. It has never to my knowledge been restored but has been worked over mechanically and cosmetically so that it looks and drives great. That is, after our mechanic did his magic. I do not plan to restore this automobile at the present time but I would like it to be my "driver."

We have since formed a team that we call "the MAL Contented," which stands for Model "A" Lovers Contented. We have collected many good used parts and have also bought a 1929 Sport Coupe which we have in process of a ground-up restoration now. I have just recently purchased a 1929 Standard Phaeton. This car is beautiful, every bit as pretty as Clarence Whale's 1928 shown on the May/Aug 1994 Model A Trader cover. I would like to state that I saved this auto, pretty as it is, from becoming a street rod. This car is fully restored and in beautiful shape, but it had been stored away for many years and needed our mechanic's magic too.

We have set up and advertised our mechanic and his garage. We have also purchased a K.R. Wilson babbitting machine and a Bridgeport mill. We are looking for a toolmaker's lathe at the present time to complete our tool crib. We hope to advertise our shop quite soon since, other than Jim Marlar's place, there are few other dedicated Model "A" shops around. Most of the true Model "A" Lovers are older men like myself and don't really relish the physical labor to get a car going.

In our combined efforts to get our Model "A" engines to start and run, we have tried a few well known tricks that seem to give us spectacular results. I must first add that I am not a proponent of synthetic oils. I feel that on these old engines, even if they have been overhauled, there are enough detergents and additives in the synthetics that if you use it full strength it may present problems downstream. The synthetic guys may argue this point but I have worked as a mechanical engineer for over thirty years and we did not go this direction in industry. However, I do recommend using a little something in the order of a can of "Slick 50" to add to your crankcase during start-up of an old engine, overhauled or not.

We have found that when obtaining an old car that has been set up for several years, certain steps should be taken before ever attempting to start these engines. This includes cars which have had earlier restoration, too, but were stored away for periods of time.


  1. Remove the carburetor and distributor. These should be checked and cleaned. A carburetor kit or a new set of gaskets is recommended. The points in the distributor should be checked, set, or replaced. The condenser should be changed although this is not mandatory. All plug and coil wires should be checked too.
  2. Remove the spark plugs and clean and set. The condition of the plugs when removed may give you a clue as to the general condition of the engine. Oily substances on the electrodes will indicate possible ring problems as an example.
  3. Before replacing the spark plugs it would be a good idea to take the crank and try to turn the motor over several times. You could even do a reasonable pressure check of the cylinders at this point. If the motor is locked up or shows resistance to rotation, you may have to pour in some penetrating oil such as kerosene or diesel fuel in each cylinder and allow to stand for several hours before trying again. Don't force!
  4. Remove the drain plug from the crank case and drain the oil. Make sure that you drain it into a clean container so that you can inspect the oil. The condition of the oil and the pressure check above are both good indicators of whether further downstream work is required.
  5. Although not mandatory, a mixture of kerosene and light weight (SAE 10W) oil can be added to the crank case. Use at least three quarts of 50/50 mixture. One can then use the battery to energize the starter and turn the motor over several revs (if only used sparingly a 12V battery can be hooked directly for faster starter energy). This may be done several times with a good rest in between to let the oil and sediment settle. Then drain the crank case and let set open for several hours.
  6. We recommend draining the gas tank if the car has set for several years. Also open and clean the settlement bowl.
  7. Now the parts can start to be reassembled. Clean and gap the spark plugs to .035". Set the points to .018" in the distributor. Replace the carburetor and attach the controls. Before inserting the distributor in the hole, pour a small quantity of oil down into the hole. This will help prelubricate the center main bearing on the crank and prevent scoring on the journal.
  8. Using the timing pin, time the points to 0-degrees top dead center on the No. 1 cylinder.
  9. Close off all the ports as required and add the recommended amount of 30W non-detergent oil minus one quart. Replace this quart with a quart of "Slick 50".
  10. When replacing the gas, it is a good idea to use Amoco or any white gas equivalent, 93 octane at least. Also add a pint of top lube to the tank, such as "Marvel Mystery Oil" and a prescribed amount of lead additive. If the motor has been overhauled and hardened valve seats were added with stainless steel valves, the lead additive will not be required. For the first tank, the engine should smoke a little but the added lubrication will give a smooth re-break-in and a lot of hours of trouble free enjoyment.
  11. It is also a good policy to change the fan belt and look closely at the water hoses. If the hoses are very old, they should be replaced too.
  12. Start the engine with the choke needle fully closed. Back off a half turn at a time until the engine starts and runs smoothly. This is the adjustment for air/fuel mixture and too much air will cause the valves to prematurely burn or too little air will give a rich mixture and the exhaust will be black. We have used this procedure on several engines and had great success. My '29 Phaeton was a mess! May be that other restorers would be interested in our system. It is all common sense, nothing more.

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Engine Overheating - Keeping Your A's Temperature in the Cool Zone (March/April 1994)

Engine overheating has been around as long as the automobile and the Model "A" is not exempt from the problem. However, the "A's" cooling system, if working properly, is more than adequate for almost any set of driving conditions you might encounter.

There are many causes for engine overheating, but once identified, most can be easily corrected. In this article, we'll look at some of the more common overheating problems and how to solve them. The information has been compiled from many sources, some of which are listed in the footnotes ( ) at the end of the article.

The obvious, and most easily checked, problems are listed first. Radiators, coolants, and thermostats are discussed in detail later in the article.

Fan Belt - Fan belts are prone to slippage and a belt that's loose will not turn the fan and water pump at the proper speed. Belt tension can be adjusted by loosening the generator mounting bolt and pulling the generator away from the engine to take out the excess slack. A 1/2 inch of play between the pulleys is about right. After the adjustment is made, tighten the generator bolt securely. Unfortunately, an unmodified Model "A" has no means of locking the generator in place and over time, the belt will loosen again. To alleviate this problem, you can use a "belt tensioning bracket" to hold the generator securely in place when driving. The bracket can be easily removed if the car is to be shown.

Fan - Fans can cause a problem if a "modern" type has been installed and the diameter or blade angle is too small to provide adequate airflow through the radiator. If you're determined to use this type of fan, check with other Model "A" owners to see what they have on their car. There's nothing wrong with the original propeller type fan that came on the Model "A" but it should be checked frequently for cracks or other damage which could make it unsafe to use.

Fan Shroud - Early Model "A's" used a shroud around the fan to increase cooling efficiency. Make sure the shroud's in place and repair any damage which could impede air flow through the radiator.

Hoses/Clamps/Petcock - A plugged radiator hose will restrict coolant flow and a leaky hose will cause coolant loss over time. Either condition can cause the engine to overheat. It's a good idea to replace both hoses even if only one is bad because the other hose is probably living on borrowed time. Check all hose clamps for tightness and if you're more interested in driving than showing the car, consider replacing the original wire hose clamps with the modern screw-adjust type. Also, make sure that the drain petcock located in the water return pipe is not leaking.

Water Pump - The Model "A" water pump is simple and robust but it can fail. If the impeller is loose on the shaft, the pump won't circulate the coolant. On the other hand, the pump may deliver too much coolant at highway speeds causing coolant loss through the radiator's overflow pipe. Some owners who frequently drive at higher speeds have removed a portion of the impeller vanes to reduce the pump's capacity. Once again, check with others to see what they're doing.

License Plates and Other Radiator Obstructions - The headlight bar seems like the ideal place to mount the license plate, but the plate does block a sizable chunk of the radiator's cooling fin area. A radiator ornament or plaque will do the same thing. On a hot day, consider removing the ornaments and flipping the license plate into a horizontal position to expose more fins to the airstream.

Incorrect Ignition Timing - An incorrectly timed engine can run hotter than normal. Check your car's timing using the standard timing pin or better yet, use a timing light as described in previous issues of MODEL A TRADER(1,2).

Incorrect Fuel Mixture - If the fuel mixture is too lean, the engine will run hot. Check your carburetor settings and reset to specifications if necessary (3).

Brakes/Wheel Alignment - Dragging brakes and poorly aligned wheels can increase the rolling resistance of the car and force the engine to work harder resulting in over-heating. The bad wheel alignment won't help your tire life either!

Bad Head Gasket/Cracks in Block - These can be classified as serious problems and if uncorrected, you'll have more to worry about than overheating! To check for exhaust leakage into the cooling system, remove the radiator cap and briefly accelerate the engine. If bubbles appear in the coolant, you could have a bad head gasket or a crack in the engine block. Oil in the coolant may also indicate a cracked block. After the necessary repairs are completed, check the integrity of the block by magnafluxing. This process will detect any minute cracks which cannot be found by other means.

Now, let's look at some of the other players in the overheating game.

Radiators - The key word in any radiator discussion is flow rate - how much water a radiator will actually pass in a given period of time. An excellent article by Walt Wawzyniak appeared in the Jan/Feb 1992 issue of MODEL A TRADER and is recommended reading (4).

According to a Walt, a good Model "A" radiator should have a flow rate of at least 38 gallons per minute. 1930-31 "AA" truck radiators should pass about 48 GPM. Anything less can result in overheating problems. Unfortunately, only a few radiator shops are equipped to perform a flow rate check but locating one is worth the effort. Model "A" owners in the Northeastern Ohio area can contact Ellet Radiator in Akron (330/784-8226) for this service.

If you can't locate a shop to do the testing, the following procedure from Jim McPherson (5) will give you some idea of your radiator's condition without removing it from the car. Remove the hoses and drain the radiator. Cap off the top and bottom hose connections and fill the radiator with water. Uncap the bottom opening and allow the radiator to drain. A "normal" radiator should drain in about four seconds.

Radiator troubles can be traced to broken or blocked tubes, an inadequate number of usable tubes remaining in the core after damaged tubes have been removed, so-called "stop leak" pellets clogging the tubes, or leaky upper or lower tanks (6). All of these problems can be diagnosed by a knowledgeable antique auto radiator shop.

Blocked tubes can be opened by "rodding" or ultrasonic cleaning. Damaged or rusted tubes can be replaced but if a large number of tubes are in bad condition, it may be less expensive to replace the radiator.
The condition of the overflow pipe should also be determined during the radiator check. A broken or rusted pipe can cause the coolant level in the radiator to be lower than normal. A broken or missing baffle plate may allow the water pump to push the coolant directly into the overflow pipe and out of the radiator.

Loose tube fins can also contribute to over-heating. If the fins are not making good contact with the tubes, heat will not be transferred into the radiator's airstream.

Coolants - The Model "A" was designed to run using plain water as a coolant. Most era drivers either drained their car's radiator before winter storage, or added some type of antifreeze for cold weather operation. Alcohol was common as an antifreeze and worked reasonably well but boiled away at about 170 degrees F. Kerosene was also used but it attacked rubber parts and boiled at such a high temperature that the engine could be damaged before overheating was detected (7).

Today's modern automotive coolants contain ethylene glycol and are designed to remain in the cooling system at all times. The boiling point of the coolant is higher than water and the solution contains a built-in rust inhibitor and water pump lubricant. When mixed 50/50 with water, ethylene glycol will protect your "A" to about 34 degrees below zero F.
There are some disadvantages to using ethylene glycol in your Model "A" - the coolant may attack some types of paint and the Model "A's" water pump can whip the solution into a green, frothy foam, impairing the cooling action. One final consideration - some automotive experts believe that ethylene glycol does not work as well as water in a non-pressurized cooling system. In actual tests, some Model "A" overheating problems disappeared after switching back to plain water (6).

If you decide to use water as a coolant, make sure that you add a good rust inhibitor to help keep the system rust free. At one time, a soluble oil was suggested as a rust inhibitor. It worked, but the oil coated the inside of the radiator, degrading its heat transfer characteristics. The experts all agree - don't use oil of any kind as a rust inhibitor!

Thermostats - According to many Model "A" owners, a good thermostat offers two important benefits:

Here's hoping that some of the information presented here will help your "A" keep it's cool during the hot weather ahead. We'd like to hear about your overheating problems and how you solved them. (JY)


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A Spring Tune-up for Your Insurance - Understanding Your Coverage (Thomas A. Brackett, CPCU, Mar/Apr 1993)

Uninsured and underinsured losses have a way of spoiling one's day! As a Model "A" hobbyist and experienced insurance agent, let me point out several restrictions and/or exclusions that appear in standard policies, especially your Homeowners and your Automobile Insurance.

You are urged to review each of these issues with your family agent. It is also recommended that you get a letter from your agent confirming how she/he is going to resolve gaps you may have with your insurance as currently written.

Personal Property Coverage
Under Coverage C, Personal Property, most Homeowners policies limit coverage on automotive accessories, equipment, or parts detached from a Model "A" to an amount not exceeding $500. If you are building a car from parts, if you have a single car disassembled and in restoration, or if you have a collection of spare parts for your car(s), that $500 limitation needs to be dealt with.

Other Structures Coverage
Under Coverage B, Other Structures (barns, garages, sheds, etc.), the policy excludes coverage if such a structure is used in whole or in part for business purposes or is rented or held for rental to any person unless used solely as a private garage. So, if you do restoration work for others or manufacture or assemble items for resale, you may have no coverage at all on outbuildings used for this business purpose.

Liability Insurance Coverage (Non Auto)
Section II, Liability Insurance, clearly excludes Bodily Injury and Property Damage arising out of business pursuits. Business pursuits are not clearly defined, but are intended to be any activity you engage in for financial gain. So, if you regularly sell parts at flea markets or if you manufacture, restore, recondition, or assemble and distribute new or used parts and/or accessories, you have no liability coverage or product liability coverage under your Homeowners policy for these activities. A Business Liability policy is needed.

Modern Car/Antique Car Insurance
These policies are often written in separate insurance companies using two different agents. This spells trouble unless you exercise great care. Your best bet is to purchase all automobile insurance through your family agent so that all coverages and limits can be dovetailed, leaving no gaps or overlaps in coverage.

If this is not a reasonable option for you, I suggest that you send a copy of your separate Antique Auto policy to your family agent and ask her/him to review it for you to see if it is compatible with your modern car coverage. If your Homeowners policy has a dollar limitation on parts, see if parts can be added to the Antique Auto policy as a separate limit of coverage.

Always be completely forthright in completing an Antique Automobile Insurance application. Answer all questions correctly and completely and use the "Remarks"" section of the application to expand upon any questions where the Yes __/No __ format of the Antique Auto application needs further explanation.

Many of us use our old cars in ways that are not strictly for Club or Antique Auto shows. Give the underwriters this information in writing so should you ever have a claim, there is no legal basis for the insurer to deny coverage.

Umbrella or Personal Excess Liability Policy
Moving to your Umbrella or Personal Excess Liability policy, you must remember to inform your agent if you have purchased Antique Auto Liability from Grundy, Condon Shelly, or one of the specialty insurers writing Antique Auto insurance. Unless your Collector Cars are listed on your Umbrella policy, and unless your liability limits on your Collector policy are adequate, you may have a gap in coverage or no excess coverage at all.

In Summary
These are but some of the more obvious restrictions and exclusions found in standard policy language that you need to act upon for proper coverage. Call your agent soon. Review in detail any of these issues that may expose you to uninsured or underinsured loss. Easy and inexpensive solutions to all these issues are available. Without exception, ask your agent to confirm your conversations in writing. The written word is your best guarantee of proper protection.

One closing thought - at regular intervals you should take clear, close-up, videos or photographs of your parts collections and of your vehicles. Keep the photographs/videos in a safe place. Should you ever have a loss, they will prove invaluable.

(Tom Bracket is an Independent Insurance Agent in Cleveland, Ohio, is a Certified Property-Casualty Underwriter, and drives a 1929 Model "A" Roadster Pickup.)

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Radiator Restoration and Repair - It's the Flow Rate That Counts! (Walter Wawzyniak, January/February 1992)

The Model "A" has a thermo-syphon cooling system. Coolant is not only pumped through the system but is also circulated by hot water from the engine block forcing the cooler 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 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:

  1. Corrosion and mineral deposits inside the tubes.
  2. Pinched or dented tubes caused by stones or other external factors.
  3. 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.

  1. Measure the flow rate before doing anything else. This can be rechecked later to verify the effectiveness of the repairs.
  2. Use a caustic solution and ultrasonic equipment to thoroughly clean the tanks and tubes.
  3. Replace or repair any damaged tubes, maintaining the original number if possible. Extensive radiator damage may require that some tubes be pinched off and soldered closed.
  4. 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.
  5. 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.
  6. Check the flow rate of the refurbished radiator. Remember, a good radiator should be able to pass from 38 to 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 flow rate and some will maintain that it 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 backflushing of the engine will clear up an overheating problem. This can be done after the radiator has 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 Considerations --

The following items are considered controversial by some Model "A" enthusiasts but in my opinion offer some very real and practical advantages:

1. 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 or scale and offers no freeze protection or water pump lubrication.

2. 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 inch 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 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.)

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