The first order of business on any tune up is to clean and tighten battery terminals. Tip toe through the tune ups

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1 The first order of business on any tune up is to clean and tighten battery terminals. Tip toe through the tune ups Story and photos by Jim Richardson The reality of the situation is, if you own a car made between THINGS YOU LL NEED: twenty and fifty years ago, unless you prefer to leave tune ups to a technician, you will eventually get to know its ignition system like family. The good news is, doing a classic car tune up is easy. The job requires only a few simple tools and perhaps an afternoon at most. Here are the basics and a few tricks and techniques the pros used in the old days: Tune up kit (points, rotor, condenser, distributor cap, sparkplugs.) Alcohol or lacquer thinner Feeler gauges Screwdrivers Flashlight or trouble light For your older classic s engine to run its Clothespins best it most likely needs to have a tune Timing light (A dwell meter is great to up every 10,000 miles. That s because have too, but not absolutely necessary most of the time.) its breaker point ignition system will have deteriorated in that time. The timing will probably have gone slightly off, and if the engine has mechanical lifters in its valve train, the valve lash, or clearance will need to be adjusted too. If these (annual in the old days) tune ups are neglected, your engine will begin to loose power, may become hard to start, and you could even end up with burned exhaust valves. On cars with mechanical lifters, valves must be adjusted to specs before tackling ignition. CONNECTIONS Before you do anything else, clean the battery and its connections. If you don t, hard starting and ignition system problems will be the eventual result. Earlier six volt systems are especially vulnerable to corrosion. Wash the top of the battery with

2 a little water and baking soda to neutralize any acid. Loosen and remove the battery cables and brighten their contact surfaces as well as the terminals on the battery. Tighten the cables back into place and smear a little dielectric grease on them to protect them from corrosion. ADJUST THE VALVES Cars equipped with hydraulic valve lifters do not need regular valve adjustments, but those equipped with mechanical (solid) lifters need valve adjustments at least every 10,000 miles or more often depending on the make. If the valves are Use numbered clothspins to keep sparkplug wires straight when changing distributor caps. not in adjustment the engine will not run at its optimum, and the situation will only deteriorate from there. An expensive valve job will be your future if you let things go long enough. Here is how to avoid that fate: Most older American car manufacturers required that the valves be adjusted hot with the engine running, but a few makes were set cold, so check your shop manual for the correct procedure before you begin. Start the car and warm it up. Let it run for at least twenty minutes so all the metal parts can expand to running clearances. Don t trust your temperature gauge; it only measures how warm the head is. FLATHEAD VALVE ADJUSTMENTS Before beginning work on the engine, put on a pair of 100% cotton work gloves with the finger tips cut off. The gloves are to After loosening with a wrench, a small length prevent burns caused by contact with the exhaust system. Never of windshield wiper hose is helpful for use gloves made of removing plugs. synthetic material because they can melt and cause burns. When it is thoroughly warmed, adjust the engine idle down to about 500 rpm but not so slow that it bucks or rolls. Loosen the bolts holding the valve covers on, then try to pry the cover(s) loose with your hands. If they stick, pop them free with a putty knife, but try not to ruin the gaskets if you can avoid it. On each lifter, loosen the locknut with one wrench and make the adjustment with the other. Check for the correct gap using a feeler gauge, then verify it by attempting to slip the next larger size gauge in the gap. If you ve got it right, the larger gauge Always check the gaps even on new sparkwon t go. plugs. Adjust all of the exhaust valves first, then do the intakes. I like to add an extra thousandth to the specifications for the exhaust valves over what is called for in your shop manual to help prevent them from tightening and burning. The engine will be a tiny bit noisier, but you will be less likely to need a valve job in the near future. OVERHEAD VALVE ADJUSTMENTS Overhead valves are easy to adjust even with the engine running. Remove the valve cover carefully, then adjust the clearances with the adjuster screws and lock nuts on the pushrod sides of the rocker arms. All you need is a

3 screwdriver and a box wrench. Slide the feeler gauge between the tip of the rocker arm and the valve stem to determine the gap. If you damaged the gaskets in order to get the valve covers off, you need to replace them. To install new gaskets, scrape the mating surfaces clean with a putty knife, then apply a little Permatex or silicone sealer and press the gasket into place on the cover. There is no need to apply sealer to both mating surfaces as there is little pressure on these seals, and you will be able to remove the valve covers for future adjustments without destroying the gaskets if one side is not glued in place. Don t over tighten sparkplugs. You will Some old cars require that their valves be set cold. As examples, crack their insulators if you do. Just snug earlier Willys, VWs, MGs and Studebakers all required cold adjustthem up evenly. ments for their engines. Cold means that the engine has not been run for several hours and is at room temperature (about seventy degrees). One by one, each cylinder must be brought to top dead center on its compression stroke so that both of its valves are completely closed before you can adjust them properly. First take out all of the sparkplugs and remove the coil wire. To roughly determine when a piston is at the top on the compression stroke put your thumb over the hole. Then have a friend crank the engine until air is forced past your thumb. Now use a wrench to turn the vibration damper on the front of the engine to get the piston exactly at top dead center. IGNITION SYSTEM The next task is to refresh your classic s ignition system, but before you do that, you need to understand its operation. It Alcohol or lacquer thinner and a lint-free coffee works like this: When your car s ignition is turned on and the filter are great for cleaning points and tools. starter actuated, current flows from the battery to the breaker points (which act as a switch) and into the primary side of the coil. The charge in the primary side of the coil sets up a magnetic field and induces a high-tension current of as high as 12,000 volts in the secondary winding. Then, as the distributor cam turns, it opens the points and breaks the current flow from the battery. The high tension current then is shunted into the condenser, which acts as a temporary storage device. When the condenser reaches a saturation point, the current then discharges back through the primary winding of the coil and into the secondary winding, which steps up the voltage to as much as 30,000 volts. This stepped up current is what goes into the high tension lead from the coil to the rotor in the distributor. From there it goes through an ignition wire to the spark plugs where it jumps the gap and ignites the fuel air mixture. The current then dissipates to ground through the engine block. This distributor cap still worked after a fashion, but it was missing its coil wire tip. Dwell refers to the length of time the points stay closed

4 while the rubbing block is riding on a flat area of the distributor cam. The points open, breaking the circuit, when the rubbing block reaches the top of a node on the cam. And all of this must happen at precisely the right moment when each piston is finishing its compression stroke and the valves are closed. SPARK PLUGS First, look over the spark plug wires carefully. If they are cracked or frayed, replace them. Plug wires must carry extremely high voltage, and they deteriorate over time, so they should be replaced every few years. One simple way to check Clean the distributor inside using a lint free cof- for bad wiring is to start the car at night or in a darkened fee filter and alcohol to prevent points from garage. If you see sparks arcing around on the engine, you need burning. to replace its wiring. Remove the spark plugs and look them over. If any are wet or rusty, a leaking head gasket or cracked block may be the cause. On the other hand, if the plugs are black and wet with oil, you probably have worn out rings or worn valve guides in the case of an overhead valve engine. However, if the plugs are dry, but black and caked with carbon, the fuel/air mixture from your carburetor is too rich. And if the plugs are brown and burned looking the engine may be running too lean. Healthy plugs usually show a little discoloration at the base of their porcelain insulators and their electrodes and their metal bases have a slightly sooty deposit on them. Plugs can be cleaned and regapped several times before they absolutely must be replaced, but they are such inexpensive items that I routinely replace them at every tune up. Whether Use a tiny bit of dielectric grease to lubricate pivot you clean up your old plugs using sandpaper, or install new on points assembly. ones though, the gaps between the electrodes must be adjusted. Don t trust the factory that made the plugs to do it. To open the gaps, use needle nose pliers. To close gaps, simply tap the electrodes gently on your work bench. DISTRIBUTOR Pop off the clips that hold the distributor cap in place. Without removing the ignition wires, push the cap out of the way. Healthy points will be aligned with one another and a medium gray in color. They should not be pitted or worn either. If they are black or dark blue, they are burned and will need to be replaced. And whatever is causing them to burn will have to be remedied as well. Possible causes of burned points are: 1) A corroded connection at the battery, voltage regulator or generator. 2) A voltage regulator that is adjusted incorrectly. 3) A generator that Get the tune up specifications for your car from the is over-charging. 4) A bad condenser or damaged condenser shop manual or an old Motors manual. lead. 5) Lubricant contamination. If you see a black line or

5 smudge under your charred points, they probably burned because oil or grease got on them. Over-zealous lubrication of the distributor is another possibility. With the moveable part of the points assembly on the node of the cam, adjust the points gap. ADVANCE MECHANISMS Chances are your distributor s advance mechanism is fine, but it never hurts to check it out. Test centrifugal (mechanical) advance systems by gripping the rotor and turning it as far as it will go, then releasing it. It should snap back with an audible click. If it doesn t, you ll need to clean the advance mechanism and replace its springs if necessary. Make sure you use springs of the same tension. On some designs such as distributors used in certain Chevrolets, the cam is fixed and the distributor head rotates as the timing is advanced. In such cases, grip the distributor head and turn it. It should snap back with a click. If it doesn t, the verdict is the same. The mechanism needs cleaning, and the springs may need replacing. To test a vacuum advance system, pull the high tension wire out of the coil so you won t zap yourself or accidentally start the car, then close the choke and open the throttle fully. Crank the engine. The breaker plate should advance. If it doesn t, the problem is probably a broken spring, or a leaking diaphragm in the vacuum chamber. On most distributors, the spring retards the spark, and the engine vacuum advances it. A broken spring can sometimes be replaced, but a torn diaphragm is terminal because vacuum advance units are sealed at the factory and can t usually be repaired. POINTS ROTOR AND CONDENSER Use a timing light to adjust timing. While engine is idling, Points can be cleaned with a points file and regapped, but here again, a tune up kit consisting of turn distributor until correct marks line up. points, rotor and condenser for most cars is so inexpensive that I believe it pays to replace these components at each tune up. This can usually be done on most cars without even removing the distributor from the engine, but there are cars, such as older flat head Fords, that require removing the distributor to do tune ups. If you must remove the distributor to do a tune up on your car, be sure to mark a line down the base of the distributor and the engine using a grease pencil so you get it back in facing the right direction, then pop the distributor cap and mark the lip of the distributor to indicate where the rotor stopped. Now loosen the bolt and clamp holding the distributor into place and pull Wet, sooty plugs mean engine is burning oil. The problem could be bad rings or worn valve. the distributor out. Later, make sure you put the distributor back in with the rotor aligned to your mark. guides.

6 Look the distributor cap over carefully for cracks or carbon tracks. If you see any, replace the cap. Also check for burned or damaged contacts inside the cap and replace the cap if you find problems. To replace a cap, before removing the ignition wires from the old cap, mark where the number one plug wire plugs into it using a grease pencil, then find that corresponding nipple on the new cap. Plug the number one spark plug into the new cap at the same nipple, then pull and plug in the wires on the new cap in sequence, one at a time. Pull off the old rotor, then remove the points and condenser. Thoroughly clean the interior of the distributor using alcohol or lacquer thinner and a paper coffee filter. The Dry, sooty plugs usually mean that the carburetor is reason for using a coffee filter is that they are lint free, out of adjustment and engine is running too rich. and any lint, as well as carbon or grease, that gets onto the points will cause them to pit and burn. Also clean the new points and your feeler gauges the same way. Put a tiny bit of dielectric grease on the pivot of the points and on the distributor cam. Install the points and condenser. Now remove the high tension lead from the coil to the distributor and have a friend just bump the starter until the rubbing block for the points is positioned exactly on the top of one of the distributor cam s nodes. Use a screwdriver and feeler gauge of the correct thickness to set the point gap according to the spec in your shop manual. Health plugs show only a little bit of soot, with clean Of course, if you are on a limited budget, you may electrodes. want to merely clean your car s ignition points with a points file, available at auto supplies, then reset the gap between them. To adjust points that have been in service, it is more accurate to set them with a dwell meter rather than gapping them with a flat gauge because of the resulting unevenness of their surfaces. TIMING Time the engine using a timing light. Check a tune up manual to determine whether your engine has its timing marks on the flywheel or on the vibration damper at the front of the engine, and note what the setting should be. For better visibility, rub a yellow grease pencil in the mark on the flywheel or pulley that must line up with the pointer before you try to adjust the timing. Hook the timing light s high tension lead to the number one spark plug wire, and the other two wires to the battery. If your distributor has a vacuum advance, tape over the end of the vacuum line going to the carburetor. Start the engine. Set the idle speed at the carburetor low enough so the centrifugal advance mechanism isn t activated. Direct the light at the timing marks on the flywheel or vibration damper. Rotate the distributor until the correct marks line up. Tighten the bolt holding the distributor clamp. Finally, take your classic out for a test drive. If it doesn t run like new, recheck your timing and tolerances.

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