Pull Out the Old Put In the New Method

High Performance HEI Distributor Installation Instructions

Step 1 - Unpack the distributor carefully and inspect it for possible shipping shipping damage.  Inspect again after removing the cap.

Step 2 - If the distributor to be replaced has not already been removed from the engine, remove its cap.  On GM HEI Distributors, unplug the pickup-to-coil harness from the cap.  Do not remove the plug wires at this time.  Crank the engine slowly until the rotor blade aims at a fixed point on the engine or firewall.  Note this for future reference.

Step 3 - Find the connect in the wiring from the distributor to the ignition switch, and unplug it.

Step 4 - Note the exact position of the vacuum advance canister.  Put a reference mark on the engine or firewall so that the new distributor may be easily installed in the same position.

Step 5 - Loosen and remove the distributor hold-down bolt and clamp.  Lift the old distributor out. If the engine had been running within the past few minutes, the distributor housing may be hot coated with hot engine oil.  Wrap a shop towel around the distributor to avoid burning your hands and catch dripping oil.

Step 6 - Install the gasket onto the distributor shaft, then lower the new distributor into position.  The rotor should be aimed at the same fixed position as was the old rotor of the old distributor, and the vacuum canister aligned with the reference mark.  After the new distributor has been lowered into place, you may find that it hasn't seated firmly against the support boss.  This indicates that the lower end of the distributor shaft is not properly aligned with the oil pump drive rod.  Do not attempt to force the distributor into position.

Step 7 - Reinstall the hold-clamp and thread the bolt just enough to exert a very slight pressure against the distributor.  If the distributor was not firmly seated, manually rotate the engine until the distributor drops down into place.

Step 8 - With the distributor properly seated, tighten the hold down bolt just enough so that the distributor is held in place, but can still be rotated with a little effort.  Again make sure that the vacuum canister is aligned with the reference mark. 

Step 9 - Remove the plug wires one at a time from the old cap and install them in the corresponding positions of the new one.  After all wires have been transferred, verify that the wire in the terminal post that is aligned with the rotor leads to number one cylinder.  IF you are unsure of cylinder number position or firing order, this information can be found in the service manual that covers your particular engine.  Put on the distributor cap.  HEI distributors, plug the pickup lead connector into the new distributor cap.

Step 10 - Reconnect the wiring leading from the distributor to the ignition switch.  On GM HEI distributors, plug the pickup lead connector into the new distributor cap.

Step 11 - Connect a timing light.  Start the engine and allow it to warm up sufficiently to idle smoothly.  It may be necessary to rotate the distributor (either clockwise or counter-clockwise) before a smooth idle can be achieved.  If the engine will not idle smoothly, the firing order may be incorrect or the rotor may not have been properly aligned during installation.  Consult a service manual for corrective procedures.

Step 12 - Consult the appropriate service manual to determine the factory-recommended initial timing and idle speed.  Set the initial spark timing with the vacuum advance line disconnected and plugged.  Advancing timing two to four degrees from the factory setting will usually provide improved performance and fuel economy.  However, timing advanced beyond factory specifications may result in detonation, which can cause engine damage.  Listen carefully - if you hear engine knocking or pinging, retard initial timing as required to eliminate it.

Break In Procedure For Distributor Gear

IMPORTANT: Premature gear failure and resulting engine damage may result from failure to follow these precautions!

• Coat gear thoroughly with zinc or moly break-in lubricant prior to installation.
   
• DO NOT use synthetic oils during the distributor gear break-in period.  Subsequently, any suitable oil may be used.
   
• Use 30 or 40 or multi-viscosity oil (i.e. 10W30)
   
• For engines that are highly modified and have oil pressures exceeding 70 psi (cold), the gear should be broken in with a racing grade mineral oil.
   
• Oil filter bypass should be removed (if vehicle is so equipped).
   
• Carefully observe gear wear after the break-in period of several hours.  Look for proper mesh, tooth alignment or excessive wear of gear teeth.

TDC Method - GM HEI distributor for an AMC V8

The first thing you have to do is put the engine in a firing position for #1 cylinder. Your situation is one of two scenarios; 1 - Your engine does not have a distributor installed and you need to install one. 2 - Your engine runs, and you need/want to replace the distributor.

For an engine that does not have a distributor in it, take the valve cover off the right side of the engine (driver side), which is the cylinder #1 side.  #1 cylinder is on the driver side front, towards the front of the vehicle.  Rotate the engine clockwise by hand until you see the exhaust valve open up in the #1 cylinder.  Continue rotating until you see the intake valve open, then close. NOW YOU ARE ON THE COMPRESSION STROKE.  Look down at the timing markings and continue rotating until you line up the line on the harmonic balancer to the 0 line on the timing markings.  Now you are at TDC for #1, which is where you need to be to proceed.

If your engine already runs, you can simply remove the distributor cap, and rotate the engine until the rotor is pointing at the plug wire (in the cap) that runs to cylinder #1. Double check your mark on the harmonic balancer, it should be at about 0 on the timing markings.  You are now at TDC for #1.   Make a reference mark somewhere in the engine bay to indicate where the rotor is pointing.  Your new distributor will point to this same location so be exact.  Also make a reference mark to locate the position of the old vacuum canister.  The new canister will point in about the same location.

Note: You can not just line up the harmonic balancer and go from there, because the V8 engine is a 4 stroke engine, and the pistons come up TWICE for every firing stroke.

Loosen and remove the distributor hold-down bolt and clamp.  Lift the old distributor out. If the engine had been running within the past few minutes, the distributor housing may be hot coated with hot engine oil.  Wrap a shop towel around the distributor to avoid burning your hands and catch dripping oil.

Install the gasket onto the distributor shaft, then lower the new distributor into position.  The rotor should be aimed at the same fixed position as was the old rotor on the old distributor, and the vacuum canister aligned with the reference mark.

IF you did not have a distributor to make reference from, decide on the cap where your #1 cylinder wire will be placed.  Clearance may be a factor in this decision.  The rotor should then point to the #1 cylinder wire on the cap.

After the new distributor has been lowered into place, you may find that it hasn't seated firmly against the support boss.  This indicates that the lower end of the distributor shaft is not properly aligned with the oil pump drive rod.  Do not attempt to force the distributor into position.

Reinstall the hold-clamp and thread the bolt just enough to exert a very slight pressure against the distributor.  If the distributor was not firmly seated, manually rotate the engine until the distributor drops down into place.

TDC Method - GM HEI distributor for an AMC V8

Step 1 - Removal of the old system - Disconnect the battery. Remove the ignition module and coil (old Duraspark components). 

Step 2 - Remove the cap off of the distributor leaving the plug wires attached to the cap and spark plugs.  If you decide to remove the wires, making note of the firing order on the cap and location of the firing order of the plugs.  Starting with the spark plug on the driver-side front plug the firing order around the cap clockwise is 1-8-4-3-6-5-7-2 (applies for most AMC V8 engines).

Step 3 - After remove the distributor cap mark the old distributor's rotor position so the new distributor can be installed in the same place. This is important to determine if your top dead center is completing the exhaust stroke or the the compression stroke.

One way to locate the start of a firing cycle is to remove the spark plug from the #1 cylinder and crank the engine in short bursts. Put your finger over the plug hole and feel for the compression stroke to force air out of the plug hole. Look down at the timing cover marking and line up the line on the harmonic balancer to the 0 line on the cover. BE CAREFUL - Watch out for the fan and make sure the Jeep is in neutral!

Step 4 - Loosen and remove the distributor hold-down bolt and clamp.  Lift the old distributor out. If the engine had been running within the past few minutes, the distributor housing may be hot coated with hot engine oil.  Wrap a shop towel around the distributor to avoid burning your hands and catch dripping oil.

Step 4 - Install the new gasket onto the shaft.  As you insert the distributor so that the rotor end is pointing in a direction to allow movement of the distributor to set proper timing. You may need to crank the engine 2 full turns to allow the distributor gear to engage the oil pump drive shaft located below the bottom of the distributor.

Step 5 - Once the distributor is fully seated lightly tighten the securing bracket so that you can properly set ignition timing after the engine is running.

Step 6 - Wiring up the HEI is easy. All that is required is 2 wires. One from a switched 12V circuit and the other from the Start side of the starter coil. This 2nd wire provides power to the distributor during engine cranking.

Step 6 - Install the cap and wires. Starting from the #1 cylinder and moving clockwise through the firing order.  AMC V8 Firing Order 1-8-4-3-6-5-7-2

The spark plug gap can be increased due to the hotter spark provided by the new distributor. Recommended gap is .050 - .055. This may be a good opportunity for some new spark plugs.

Setting the Timing

After all of the wires are installed check all connections and make sure everything is cleaned up and out of the way of moving parts. Attach a timing light so you can set the engine timing after it starts.

Reconnect the battery and start the engine. If you timed the engine correctly it should fire right up. You will probably need to rotate the distributor to better set the timing before you use the light. When the engine runs smooth you should fine set the timing using the light. The recommended ignition timing is 8 degrees BTC with distributor vacuum advance disconnected and the engine at idle. The Jeep was set a bit higher about 10 degrees, high enough just before engine ping was heard.

If the engine doesn't start or run correctly you may have the distributor out of time. It is possible that the distributor will need to be removed and re-timed, refer to the above.
 

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