• Installing Delco EST - Replacing Conventional Points Ignition on a Crusader

    Approximately, two years ago our old girl started showing signs of a cold. She started out with the occasional sniffles that slowly progressed over time from a random hiccup to more frequent engine surging. As the doctor, I knew that for an engine to run efficiently it needed three things in the proper proportions and at the right time, fuel, air and ignition. So the series of tests began.
    I methodically went through the lists of possibilities and even some impossibilities, clogged fuel vents, installed new fuel lines, complete tune-ups, checked the fuel pump's pressure and installed new coils. None of these actions seemed to solve the problem and it gradually became worse.

    This left only the ignition system as the likely culprit, more specifically the distributor. The existing distributor was of the conventional type (points and condenser) with a centrifugal spark advance operated via counter weights. From the boat's behavior, it was apparent that the distributor was worn out.

    So I reached deep into my pocket book and purchased two Delco Electronic Distributor kits and prepared for surgery. The distributors did not come with instructions, but my local mechanic was kind enough to make photocopies of information he had for a different engine. After quite a while of sorting out the differences in installation procedures discussed on the photocopies compared to my engines the work began.

    The installation was successful, and I am happy to say the problem is cured and no more sniffles. Even better, the boat starts much easier and runs more smoothly. Additionally, gas mileage has improved and my engines have more power. This is the second boat that I have converted to an electronic form of ignition and have been greatly satisfied on both accounts.

    The steps below describe the general procedure for replacing your old worn out conventional ignition.

    1. If you are careful and do not rotate the engine after beginning this procedure, it is not necessary to rotate the number one cylinder to Top Dead Center (TDC). Instead using a permanent marker, trace all of the plug wires and mark their cylinder numbers on the old distributor cap. Compare the firing sequence with the order of the numbers that you have written on the cap, they should match (if you have twin engines, one engine will likely have a different firing sequence). Also mark cylinder 1's location on the engine block near the distributor hole.

    Attachment 3305

    2. Remove the plug and coil wire(s) from the distributor cap.

    3. Now remove the distributor cap from the distributor and using a permanent marker, mark the position of the rotor's alignment relative to the engine (direction the rotor is pointing) on the engine housing. When installing the new distributor, the rotor must be aligned to the same location.

    Attachment 3306

    4. Remove the clamp bolt and distributor hold down clamp.

    Attachment 3260
    5. Disconnect the leads from the negative (-) terminal of the ignition coil. These will include the distributor primary wire (normally black running from negative terminal of coil to distributor base terminal) possibly a shift-interrupt lead (black or brown) and tachometer lead (brown or gray). Always consult the wiring diagram applicable to your specific engine for the correct color codes. In the image below some of the wires fell prey to paint and the colors are hidden, but the labels show the correct color.

    Attachment 3274
    6. Lift the old distributor from the engine slowly, as you lift you will notice the rotor turn slightly. Note the amount that it turns and its position relative to its original position (your mark). When you install the new distributor you will position the rotor at this new relative position then slide it down into the housing. As you slide the new distributor into the housing, the rotor will turn the opposite direction and same amount and should line up with your mark (the rotor turns because of the spiral alignment of the gears at the bottom of the distributor and the cam gear within the engine).

    7. Check the distributor gear for damage or unusual wear, if either is noted, the cam gear within the engine may need replacement. Until installation of the new distributor do not allow any debris to fall into the distributor hole.

    Attachment 3276
    8. Now remove the leads from the positive side of the distributor: purple to resistor and purple to starter. One of these leads is the feed from the starter motor "R" terminal that bypasses the resistor during starting to deliver a full 12 volts to the coil. The other lead is from the resistor that is the stepped down voltage delivered to the coil while the engine is running. These leads will not be used with the new ignition system and should be taped off and secured.

    Attachment 3279
    9. Remove the coil and resistor, these will not be used with the new ignition system.

    Attachment 3307

    10. Apply a small amount of lubricant to the new distributor's gear then remove the cap. Install a new gasket around the distributor hole. Align the rotor to the new relative position noted in step 6 above. Slowly slide the new distributor into the distributor hole. You should be able to feel when the distributor gear makes contact with the cam gear, you may have to wiggle the rotor slightly to allow the distributor gear and cam gear to mesh properly and the distributor to fully seat. Make sure the distributor is fully seated, the end of the distributor shaft will engage the oil pump drive. With the distributor fully seated, note the alignment of the rotor and the rotor direction mark you noted in step 3. If the rotor is not properly aligned, remove the distributor and try again.

    Attachment 3282

    11. Install the distributor hold down clamp and bolt but leave the assembly loose enough to rotate the distributor housing for timing. Install the distributor cap. Align one of the distributor cap towers with the position you marked for the #1 cylinder you noted in step 1. Begin installing the plug wires in the sequence you noted earlier in step 1. Make sure the wires are fully seated, the short boots connect to the distributor cap while the long boots connect to the spark plugs.

    Attachment 3289
    12. Install the new coil mounting plate, the mounting plate is pre-drilled, but may require slight modification to align with the old coil's mounting location.

    Attachment 3290
    13. Install the new coil to the mounting plate, use two screws minimum.

    Attachment 3291
    14. Install the distributor to coil wiring harness. One end goes to the two terminal connector on the coil while the other connects to the mating connector on the coil.

    Attachment 3292
    15. Install the ignition/tach connector (connector with purple and gray wire) to the ignition coil. The connector's gray (tach) wire should be spliced to the old tach lead disconnected in step 5 above. For best results use a water-proof, heat shrink style butt splice connector.

    Attachment 3293
    16. This is where it can get confusing since some of the instructions that come with the kit (if any) mention shift-interrupt circuits and show the initial timing connector (plug with white wire loop and brown wire with an alligator clip). Also you may see instructions telling you to clip the wire on the shift interrupt connector close to the body (disregard this step). In my kit the initial timing connector is really a timing harness (#98073) and has the engine timing plug (male connector) connected to the other end of the brown wire instead of an alligator clip. The reason for this, is the plug can be left connected to the distributor on this model instead of replacing it with the clipped shift interrupt connector mentioned above.

    Attachment 3308

    17. Plug the timing harness into the remaining slot in the distributor. Now it is time to wire up the timing plug harness (plug with black wire, purple/white wire and female timing plug). The black wire is grounded to a convenient location on the block. The purple/white wire needs +12V power shown in in next step.

    18. At this point on my boat, I am left with a +12V purple to ignition wire (source of power) and yellow to alternator wire (from step 8). I also have a purple/white from the timing plug harness (image above) and a purple wire from the ignition/tach connector (step 15). The +12V purple to ignition wire will provide the source of 12V power that is needed for the remaining three wires. Therefore they should be spliced together as shown below.

    Attachment 3302
    Timing the Engine

    1. Connect a timing light to the No. 1 spark plug, connect the power supply to lead of the timing light to the +12V pole of the battery.

    2. Verify the distributor hold down clamp is loose enough to allow rotation of the distributor, ensure the No. 1 plug wire on the distributor is still aligned with the Cylinder No. 1 position noted in step 1.

    3. Change the timing plug to the "TIME" position. This locks out the automatic electronic spark advance system.

    Attachment 3303

    4. Start the engine and allow it to run at normal idle speed. If the engine doesn't start or won't idle smoothly, you can rotate the distributor slightly until a smooth idle is achieved. The new distributor may have changed your idle speed slightly since it is more efficient than the old points system and this is okay for now.

    5. Aim the timing light at the timing tab on the engine. Adjust the timing by rotating the distributor until the timing mark (on flywheel or pulley) aligns at the proper position as recommended by the manufacturer.

    6. If the idle speed is not at manufacturer recommended settings, adjust the idle stop screw on your carburetor to achieve the desired rpm and re-check the timing.

    7. Use care to not disturb the distributor and tighten the hold down clamp bolt to prevent the distributor from slipping.

    8. Return the timing plug to the "RUN" position to enable the electronic spark advance.

    Attachment 3304

    Congratulations, you are done. Now enjoy the benefits of an electronic ignition.

    Attachment 3323


    Comments 7 Comments
    1. infidel4375's Avatar
      infidel4375 -
      can anyone tell me if you can use the same kit on both right and left rotating engines?
    1. Roger's Avatar
      Roger -
      Everything is the same on the counter rotating distributor except the gear at the bottom, it needs to be of the counter rotating variety as well. When I changed ours I found the gear on my old distributor was in great shape so I reused it and was able to use a standard rotating one. This was good for me because at the time the counter rotating version was on back order.
    1. infidel4375's Avatar
      infidel4375 -
      Quote Originally Posted by Roger View Post
      Everything is the same on the counter rotating distributor except the gear at the bottom, it needs to be of the counter rotating variety as well. When I changed ours I found the gear on my old distributor was in great shape so I reused it and was able to use a standard rotating one. This was good for me because at the time the counter rotating version was on back order.
      Many thanks for this, I especially liked your solution of using the old gear. I spoke to someone at "marineenginess4less" because they till have the Delco Voyager replacement kits and they told me that the older small block chevy engines used the same camshaft gear on both lh and rh engines so, given that my motors are 1987 vintage, that's what I went with. I'll let you know in late March when I do the work.
    1. Cap'n Ray's Avatar
      Cap'n Ray -
      If you’re up to it, take lots of photos/ video and share a write-up of the process! Your project could really help someone else out in the future! We love projects like this.
    1. infidel4375's Avatar
      infidel4375 -
      I'll probably do this in late March when it's a little warmer in CT. I'll detail the project at that time.
      [QUOTE=Cap'n Ray;10637]If you’re up to it, take lots of photos/ video and share a write
    1. ADVANCED BOATS's Avatar
      I'm looking to do this in the very near future on my twin 1985 Crusader 220s. Any updates on this or additional tips that will make it even less intimidating than it appears it might be.
    1. infidel4375's Avatar
      infidel4375 -
      I've successfully completed this conversion on my 87 Crusaders 275s. Don't know if the 220s are the 302 engines; mine are the 350s but I imagine that the process is the same. The article you reference in the forum is generally excellent and very helpful. A couple of things:
      aside from marking the distributor before removing it, make sure that you also mark the location of the #1 cylinder on the distributor cap.
      I had to drill an additional hole in the coil bracket to secure it to the engine. It helps a lot to have access to a drillpress
      Rather than taping up the wire from the solenoid to the resistor, remove it altogether from the solenoid.
      Reference is made to an alligator clip on the timing harness that plugs into the distributor. Mine did not have the clip, so I attached a female plug to the end of the black lead, then made a wire with a matching male plug and an alligator clip. You will need to energize this when timing the engine, and I simply unplugged from the distributor harness when done.

      good luck,

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