Prestolite vs holly distributor

[Imperialdog]

I have a '78 Scout II with the 345. After having a mechanic replace a cracked valve ($$), it was recommended to me to replace the distributor. According to to the manual, I have a prestolite IDN-4000 series. When I ordered a new distributor from Scoutparts, they sent me a Holly. I installed that with an new pertronix ignitor II coded for the Holly and it would not start. I put back the points that came with it and it still will not start. Have I made a major "bonehead" move here? Non gold box. TIA

[orodos]

Any more info?

[Eric VanBuren]

First mistake was ordering from Scoutparts. Your truck came with the Prestolie electronic IF you really needed a "new" distributor you could have gotten the correct one at your Local Napa for less than the Holley points unit and the Pertronix II.

Have you checked to see if you have spark? Did you line everything up on #8 compression before removing the original distributor and line up the new one on #8 when you put it in?

You should not try and run points on your rig w/o making some changes such as adding a ballast resistor and the resistor by-pass circuit. W/o the resistor you'll fry the points and possibly the coil. W/o the by-pass circuit you'll have trouble starting it particularly in colder weather.

[Will Marsh]

First off, I'd just return the thing to Scoutparts if I could. You can buy either a Prestolite or Holley Points distributor from NAPA or O'Reilly for ~$100 exchange. I don't even want to guess what Scoutparts charged you for it.

Personally I prefer the Holley Distributors. A couple of questions to get you a good answer.

Did you get the timing right using #8 cylinder to time it? Are you getting any spark out of the distributor?

Was your original Prestolite a points or electronic distributor?

Did you put the Prestolite cap on the Holley with your old wires, or did you buy new wires to fit the Holley cap?

HTH,

Will Marsh

[Imperialdog]

The original dist was electronic, stock, that big resin coated hockey puck, if my corroded brain cells serve. That failed around 1992, and I installed a pertonix ignitor then, which I never had to mess with since now. Is the Holly compatable with an engine that had a Prestolite, or do I need a Prestolite? I admit to being a chippie, electronics are confounding to me. It seems that I have no spark. I get turnover but no sign of ignition- it smells like gas after cranking for 20 or 30 seconds, no ignition at all. When I swapped everything I had it in neutral and just aligned the new one so the paddle slipped in just fine. The rotor seemed to be pointing at #1. At this point the rotor stops at random positions in the cycle, not at #1. I really want to know if the Holly will work with me or if I eff'ed up getting that. Thanks

[Eric VanBuren]

Yes a Holley dist will work in the place of the Prestolite.

[RD Durham]

All distributors used in International Harvester SV engines (305, 345 & 392) are interchangeable. What you may have to do is adjust your wiring. Points distributors used a resistance wire, so if you are adding a points distributor you need to check if you have a resistance wire or add an in line resistor, which is available for automobiles & can be purchased as most auto parts stores. If you are adding a different electronic distributor then adjust your wiring to accommodate a different electronic distributor. I don’t remember the wiring differences off the top of my head but they are shown in the shop manuals. I’m guessing but it sounds like you got your wiring mixed up when you swapped distributors. I’d go back and verify that you have the correct wires going the appropriate connections. If you got your wiring mixed up you may have also fried you Petronix unit.

Check the wiring for your distributor, that it is properly set up & connected and if that is OK then verify that you have spark. Pull a plug wire and either use an old spark plug or a short bolt that will fit in the spark plug boot clamp. With a plug just lay it on the engine block where it will ground out and then crank the engine looking for a spark. You could also ground the plug with a wire from the plug body to the negative terminal of the battery. DO NOT directly ground out the spark plug body to the negative terminal. Car batteries produce hydrogen gas as part of the charge/discharge process and the spark could ignite this gas if it is present. If you use a small bolt just hold the free end of the bolt a short distance (approximately 1/8 inch) from the engine block and look for a spark. MAKE SURE that you are not in contact with the bolt in any way or you will get a good electric shock. Good luck.

I also agree with the others about Scout Parts. How they manage to stay in business is beyond me. Their prices far exceed what you can readily get from most auto parts stores, and their prices for used items is ridiculous.

[scoutboy74]

This sounds like a case of fixing something that wasn't broken...and then breaking it in the process. You had a cracked valve. That was repaired. Shouldn't that have been drive happy time? Why were you encouraged to replace the presto? Had it failed?

[Scott Hickman]

Send the point dizzy back to where it came from.

Go to NAPA,
buy a Prestolite electronic distributor: NRD#4844822 or NRD#4844451,
New cap: Eclin # AL162,
New rotor: Eclin # AL163,
New Plug wire set: Belden #700259,
Eight (8) spark plugs: Autolite #ASP85 - gap to .035"

Set timing off of #8 cylinder - which is the aft cylinder on the right bank (pasenger side). Initially set to 5 degrees BTDC (before top dead center)
Timing makes are on the front of the engine, on the harmonic balancer, behind the crank pulley.

IH SV-8 Engine Firing order is 1-8-4-3-6-5-7-2.

Left bank is 1-3-5-7 from front to rear (driver side).
Right bank is 2-4-6-8 from front to rear (passenger side).
The distributor rotates clockwise, as viewed from the top.

[Imperialdog]

The vacuum advance was not working, thats why I decided to replace the whole thing as an upgrade. By adding the ignitor II I was hoping to increase mileage. I replaced the stock electronic hockey puck in the dist in the 90's when it failed with an ignitor and never had to touch it since. With the engine rebuild, it seemed to make sense for just a couple hundred more to have a new ignition and save on gas for the next 10 years....