"Real World" Horsepower

Fellow AMC'ers, This editorial is not meant to belittle anyone or their efforts, but to educate and bring to light some misguided truths about horsepower and how it is attained. In recent past, I've seen and heard some really ridiculous AMC horsepower claims. What is amusing about this is the way people come up with their "horsepower". Webster's Dictionary defines "Horsepower" as: "A unit of mechanical power equal to the power needed to raise 33,000 pounds at the rate of one foot per minute. That is 16 and one half TONS! Roughly the weight of FIVE two seater AMXs! True engine horsepower can only be measured on an engine dyno. Rear wheel (power to the ground) horsepower can only be measured on a chassis dyno. The difference between the two readings is your loss of horsepower through the drivetrain. Simple as that.

Desk top dyno programs, calculators, pencil and paper and a Summit catalog just don't cut it. Dyno tuning is expensive, time consuming and precise. Dynos don't lie. A lot of things factor in when trying to calculate useable, "Real World" horsepower. Size of the engine, specifications of components, compression, cylinder head configuration, altitude, weather conditions, drivetrain efficiency, fuel delivery, type of fuel, ignition systems, timing, and so on, and so forth. Not everyone has access to dyno equipment, if this is the case for you, at least engage the help and advise of a professional at a reputable shop when it comes to tuning your engine. The point is, your horsepower and torque goals should be realistic. Choose components that compliment each other. For example, a Torker manifold on a stock 360 might look cool, but it doesn't work. An R4B with a Comp 270 Magnum cam is a well matched combo in terms of the power range 2000 to 6000 rpm. Other things can be done to enhance these components like a mild port/polish on the heads, a "hot" ignition, and a tuned exhaust  system.

Most of what you see in performance magazines is based on small block Chevy, Ford or Mopar engines. Not an AMC. Just because the article or advertisment says, "Use our cam and you'll get 40 more horsepower!" doesn't mean that you'll get the same out of your AMC motor. You won't. There are too many variables to consider. Bottom line: Don't believe everything you read. Research your components wisely BEFORE you buy them. Pay attention to details BEFORE you build the engine. Choose a combination that is best suited to your stock or performance needs. But, if you really want to know if what you've chosen is working to its full potential, and you want "The Truth", DYNO IT! What it can do for you in the end can not be measured in dollars spent, the smile (or frown) on your face tells the whole story. Been there, done that many times! I will be expanding more on this issue at a later date. If you need further info or advice on this or any other AMC subject, give me a call.

Remember: "Vision without action is a dream. Action without vision is a nightmare". 

Front Coil Springs

There is only one way to correctly lower the front end of your AMC car: First things first. NEVER lower the front end of a car by cutting the coil springs, or heating them up to collapse them. These methods are proven DANGER! Have you ever noticed that both ends of AMC front coil springs are FLAT wound? There is a good reason for this. It keeps the spring located correctly in the spring seat or trunnion cup depending in the year of the car. Cutting the coil removes the flat wound bottom and cocks the spring seat sideways producing undue stress on upper control arm bushings, the spring seat bushings, and ball joints. Sooner or later, the coil will also shift position and even pop out on a good bump. The load rating of the spring will also change if cut or heated. It is best to determine the ride height of the original spring by measuring the coil from top to bottom. Do one side at a time. To get a fairly accurate measurement, put a floor jack under the lower control arm and raise the car just enough to get the wheel off the ground. Remove the wheel and get the measurement. Doesn't have to be exact, but the closer, the better. Contact any good suspension shop and bring the old coils with you. They will measure the diameter of the spring "Wire". This, combined with your ride height measurement will tell them how to make your NEW coil springs. You tell them how much less ride height you want, let's say 2", and presto! You've got a new set of coils made to handle your front end weight of your car AND you have the two inch drop you wanted. Cost is usually between $150 and $200 for the new set of coils, and well worth it. Save up the money and do it right.

Better to be safe than sorry: Whenever you lower the front end, you lose suspension travel. Having a spring made that has a "Wire" that is a few thousandths bigger, will help to keep the front end from bottoming out on the lower control arms. The use of a quality shock absorber, like KYB, doesn't hurt either. And ALWAYS have your front end re-aligned whenever you change the coils. As far as the tool necessary to remove 70/up coil springs safely, I use a Coil spring compressor from "Mac" tools, Part # CC520. It compresses the spring from the inside! You have to remove the shock tower and shock absorber, and the tool is lowered in thru the top, hooks on the bottom of the coil and has a "Fork" that slips thru the coil on the outside. It has a long threaded stud that you turn from the top and compresses the spring. Super tool! Super easy, quick and safe to use.

I have a ton of experience with AMC front coil springs from all my years of racing the Silver State Challenge, and this knowledge has really helped me on my "street" cars.

Broken Eagle Axles

In regards to the problem with Eagle right rear axles breaking inside the hub, this IS a common occurance. I've had dozens of people tell me they've had this same problem. It has happened to my Wife twice now with our 81 Eagle Sport Wagon. Having the wheel literally come off the car and roll past you on the freeway at 60 mph, is not a pleasent experience. What happens is quite simple. The right rear axle shaft breaks off inside the hub, and at that point, the only thing holding the wheel on the car is the press fit of the axle on the hub. One good bump and..............SEE YA! What's interesting about all of this is that it is not usually caused from driving thru potholes, bumps, offroad motos, etc. Why it happens:

I have an AMC Technical Service Bulletin which says that on SOME, (not all) 80 thru 82 Eagles, the right rear axle nut was found to be SERIOUSLY over-torqued! Apparently, on the assembly line. The undue stress and "stretch", similar to that of any nut/bolt application would certainly show its ugly results at some point. For example, we've all done this at one point or another; what happens when you over-tighten a bolt on, let's say, your water pump? You got it, it snaps off. Or over-tightening a nut on a bolt? The threads strip or the bolt/stud snaps. Same thing goes with the axle, only it takes longer for it to happen because of its size, as well as the fact that the hub has a tapered torque fit. Even though 99% of customer complaints were on the right rear axle, I suggest pulling the hubs off on both sides, and having the axle shafts (and hubs) Magnafluxed for possible cracks. Also, it's a good idea to install new axle bearings and seals at the same time. It's cheap insurance and peace of mind.

Axle interchangability: All years of Eagle rear ends are the same in terms of design, but the axles are different from left to right. All left axles are the same, and all right axles are the same, but you can't install a left on the right and vice versa. The part numbers are different as well as the length. Pretty much self explanitory. Use the correct EAGLE axle. What year Eagle axle should you use to help increase your chances that this won't happen again? Since the problem seems to have occured in mostly 80/82 Eagles, I suggest anything from a 1983/up Eagle. When the axle shaft broke on our 81 Eagle the first time, I replaced it with a used one out of a 1980 SX/4 and, guess what? It broke again. On the second go-round, I used an axle from a 1982 SX/4, and it also broke. Finally, I used an axle from a 1984 Eagle 4-door sedan and (knock on wood) I haven't had any problems since. Before I installed the axle, (knowing what I know now) I did remove the hub had the parts checked for cracks. Tested OK, installed a new bearing and seal, and she's still doing fine 4 years later. If you've ever had this problem happen to you, the thought of it happening again will probably haunt you for as long as you own the car. Permanent peace of mind might come in the form of a different rear end from some other model AMC. Interchangability with other models and years is only limited to your imagination. Remember that YOU have the control of the tape measure! So choose wisely. Most any AMC passenger car rear ends can be made to work as long as you think it through, and do it correctly. Or, the only other solution is custom made solid axles from Moser, or a similar company.

1968, 1969 Floor Shifters

How many of you have (or have had) a problem with your 1968, 1969 auto floor shifter center release button not popping back up? This is a necessary function as it keeps the shifter locked into certain positions for saftey reasons. The problem is usually that the spring at the bottom of the shifter assembly is broken. Here is an easy way to fix the problem without tearing the console apart, and without using any tools!

Solution: Go to the hardware store and buy a "compression" type spring with the following dimensions: 1/2" inside diameter x 3/4" long and has a material thickness of about 1/32". Unscrew the black release button in the middle of the shifter knob. Slide the spring over the threaded shaft, and screw the black button back on until it stops. Problem solved! Yes, it's just that easy!

This fix will also work in the 70 "pistol grip" shifter however, the center chrome button is held on with a barrel clip, and can be a little stubborn to remove. Just get a good grip on the button and pull straight up, drop the spring on the shaft, and press the center button back on.

Fuel Gauge Problems

Troubleshooting 1968 - 1970 Fuel Gauge Problems: If your gas gauge was working OK, but all of a sudden it quits working altogether, or the needle is reading LOWER than the amount of gas that is really in the tank, then this is the fix for you. 68/70 AMX and Javelin fuel gauge test. This will be a process of elimination. Let's start with the gauge itself.

Put the car on jack stands and let the rear suspension hang down. Remove the passenger rear wheel. Doing this will give you plenty of access to the fuel tank sending unit. First things first. Is the yellow feed wire connected to the sending unit? If not, make sure the terminal on the sending unit is clean, also make sure the yellow wire socket is clean and that it fits tightly on the sending unit terminal. Check the sending unit black ground wire. Make sure it is clean and connected. Turn the key on and check the gauge. If it still doesn't work, then try this next test. Remove the yellow feed wire from the sending unit. Do not remove the ground wire! Find yourself a 5 to 6 foot long jumper wire the same gauge as the yellow sending unit wire, and strip both ends of the jumper back about 1/2 an inch. Take one end of the jumper wire and push it into the yellow feed wire socket. Bring the other end over to the driver side of the car. Sit in the car, turn the ignition to the "ON" position and touch the end of the wire to any one of the scuff plate screws. What you're doing is "grounding the gauge". If the needle goes all the way past "full", then the problem IS NOT the gauge. if the needle doesn't move at all, then the problem is in the feed wire from the gauge to the sending unit. Here's where it gets interesting. In 70 there was an option known as a "low fuel warning system". It was designed to warn the driver when the fuel level gets to 1/4 of a tank or less. When the fuel level gets to 1/4 tank, a light flashes in the center of the fuel gauge. If you have this system in the car, then chances are this is the reason why your gas gauge won't read at all. If you have a 68 car, or if you don't have the low fuel system in your 69 or 70, then the problem IS the sending unit in the gas tank. (usually the float, or a burned out unit all together) To determine whether or not you have a low fuel warning system, look closely at the face of the fuel gauge. Between the "F" and the "E" will be what looks like a tiny rectangle slot. If you see this slot, you have a low fuel system. It operates off of a relay located under the dash directly right of the steering column, secured to the dash frame with one screw. It has a 4-wire plug off the relay that connects to the back of the instrument cluster circuit board. It is not enough to simply unplug the relay and solve the problem. You MUST COMPLETELY REMOVE the 4-wire harness from the back of the circuit board. The key to doing this correctly is dependent on the orange light wire which is part of this 4-wire harness. Notice how the orange light wire is plugged into a black plastic socket? The socket is held onto the circuit board by one of the nuts that holds the fuel gauge into the cluster. Remove the nut and take off the socket. Make sure you put the nut back on and snug it down! By doing this you have reconnected the original circuit, only without the low fuel system. Put your cluster back in and make sure your main harness plug in connected. Turn the key on and check the gauge. If it works, then your problem was a burned out low\ fuel relay. If you don't want to go searching for an NOS replacement relay (used relays are not reliable, nor are they accurate) then just put you dash back together and leave it alone. Even when the low fuel system is working correctly, it can be a real annoyance as the light will continue to blink until you decide to fill the tank. I believe this was really designed for long trips where you don't pay a whole lot of attention to the gauge as you're cruising along, and starts to blink when you're low on gas, or reminds you to wake up and go get some gas! I hope this helps answer questions on this subject. As you can see, these are fairly simple tests to tell you EXACTLY where the problem is and how to fix it. Good luck!

For more information on these, or any other AMC related subject, don't hesitate to give me a call.