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| Rotor/Reluctor Phasing https://slantsix.org/forum/viewtopic.php?t=59710 |
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| Author: | ntsqd [ Tue May 31, 2016 9:30 am ] |
| Post subject: | Rotor/Reluctor Phasing |
Working on installing the rebuilt 170, got to installing the new electronic dist. and noticed that the rotor & reluctor phasing was off. It is advanced of the cap's conductor by 20°-25° with the mech and vac. advance both at zero. Thought "OK, chinese dist., go get the old one." Nah, it's off by about the same amount. I am used to Dura-Spark systems where the rotor/reluctor phasing is maybe 15° advanced of the cap terminal, at most. This looks really wrong to me and I'm a little surprised that it ran at all. Have I got two bad dist's that by pure chance are bad by the same amount, or is this normal? Depending on how the reluctor is located on the upper shaft my temptation is to align it better, but I thought I'd ask about this first. |
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| Author: | Badvert65 [ Tue May 31, 2016 9:41 am ] |
| Post subject: | |
Not an answer, but I am curious how you are checking this. I'd like to check mine as well (OE Mopar dist). |
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| Author: | ntsqd [ Tue May 31, 2016 10:33 am ] |
| Post subject: | |
Simple physical alignment. Mark the center of the cap's #1 terminal on the dist. body. Then rotate the shaft until the reluctor's lobe is centered on the pick-up coil's core and the rotor is roughly in the right place (i.e. have the correct reluctor lobe). |
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| Author: | SlantSixDan [ Tue May 31, 2016 11:30 am ] |
| Post subject: | |
Paging DusterIdiot…! |
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| Author: | DusterIdiot [ Wed Jun 01, 2016 6:30 am ] |
| Post subject: | Pics? |
Do you have a picture of what you are talking about? When installing a distributor I pull a trick from the EFI guys and use an old cap with a 1/2" hole drilled between the #1 tower and the center tower...that will give you a easy visual when having to adjust some more initial, remember there are 2 places to adjust the distributor when adjusting timing. If the adjustment is in the distributor itself, I would check the mechanism and make sure something isn't hanging up the mechanical advance mechanism.... I pulled a few OEM cores I have and in each case the rotor pointing directly at the #1 tower will line a reluctor tooth up with the pickup tooth. |
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| Author: | Danarchy [ Wed Jun 01, 2016 6:58 am ] |
| Post subject: | |
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| Author: | ntsqd [ Thu Jun 02, 2016 7:38 am ] |
| Post subject: | |
Thought that I was going to get time to take a picture last night, but it didn't happen. I'll get to it ASAP! This is internal to the distributor. If I align the #1 reluctor lobe to be centered on the pick-up coil's core, the rotor is pointing roughly in the direction of the right edge of the tab that index's the cap. Which on these dist's is considerably off from where the terminal is. Looking at Danarchy's pic has me a little confused now about exactly where that tab is. |
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| Author: | ntsqd [ Fri Jun 03, 2016 5:42 pm ] |
| Post subject: | |
All I can say is it must have been a long day. Now that I've had a chance to mark the cap terminal positions and look at it in good light it certainly doesn't look as out of whack as I thought. 
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| Author: | DusterIdiot [ Fri Jun 03, 2016 7:56 pm ] |
| Post subject: | You're good... |
That is the normal EI reluctor to rotor position...you are good to go... it looks weird but it's not.... If you are dialing in some initial static, use the drilled or cut away junk cap... if the balancer has not slipped.... set the timing mark as you would like it (and #1 rockers are "loose") and adjust the rotor to point to the #1 tower, lock it down and time and test drive it... 
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| Author: | ntsqd [ Sat Jun 04, 2016 6:40 am ] |
| Post subject: | |
Thanks, all! Feeling more than a little sheepish....... That path to initial static timing was exactly where I was headed when I noticed what I thought I saw. Used to setting the initial on the Toyota electronic converted Bosch 010 in my old dune buggy's 1955cc air cooler exactly this way. Those have mech. advance at idle, so an old type timing light is near useless. With the wide reluctor lobes of the Toyota and Ford Dura-Spark reluctors I soon learned that 1/2 the lobe past the pick-up coil core was where the correct timing was. These lobes are so narrow that I doubt it matters. |
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| Author: | Danarchy [ Sat Jun 04, 2016 7:52 am ] |
| Post subject: | |
I originally cut the hole in the cap for the same reason.(alignment seemed wacky) I have all the parts to convert to HEI, but my car runs so well with points I haven't done it yet. (If it ain't broke don't fix it!:lol: ) |
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| Author: | ntsqd [ Sat Jun 04, 2016 9:15 am ] |
| Post subject: | |
Mine came to me with the std Mopar conversion. I was OK with that though I seriously pondered converting the module to Dura-Spark II when I was dealing with inferior parts. Then I realized that the easiest way to get the tach signal (in the form expected) for the TBI system was to convert to the 8 pin GM HEI module used by the TBI system. I'm not a fan of GM HEI modules, but they do work. Cooked the first module trying to use something else for the thermal grease. Worked well for quite a while, and then it didn't. I've got to say that it starts and runs better with the GM module than it ever did with any of the Mopar modules. It would rapidly light the failing old engine when the Mopar module took a lot of cranking to get started. Part of that may be the coil as I converted to the TBI's e-core coil at the same time. My advice based on these experiences is: By-pass the Mopar conversion kit, buy the electronic distributor only (got my new one from my LAPS), use the GM module, use the GM thermal Grease (I've read of a Radio Shack substitute, but no experience with it), put the GM module on some form of heat-sink - simple aluminum bracket with some thickness to it seems to be enough, run power to the GM module via a relay with at least a 12ga. wire, make your own simple harness using metripack or weatherpack connectors (I converted the dist. to weatherpack), & use tidy wiring practices for a robust system. For instance, one of the things that I don't like about the GM modules is the exposed inductive pick-up connection. On the 8 pin modules the "external connections" (power, coil, EFI stuff, etc.) are in sealed Metripack connectors, but the two terminals for the pick-up are just tabs sticking out of the molding. These are the lowest voltage connections of all of them, and they're most exposed to corrosion! There also is nothing to maintain that connection against vibration. The terminals on the module are also an odd size, I had to look specifically for female spades that fit right. I bought uninsulated connectors, crimped them, and then covered them with adhesive lined heat shrink. I then slid a bigger piece of adhesive lined heat-shrink over both terminals, placed them on the module, and then shrunk it into place. Some dielectric grease and several small T&B zip-ties later I feel it is reasonably robust. |
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| Author: | SlantSixDan [ Sat Jun 04, 2016 11:11 am ] |
| Post subject: | |
Quote: I'm not a fan of GM HEI modules (…) I've got to say that it starts and runs better with the GM module than it ever did with any of the Mopar modules. It would rapidly light the failing old engine when the Mopar module took a lot of cranking to get started.
That sounds like the makings of a changed opinion, right there.  Quote: My advice based on these experiences is: By-pass the Mopar conversion kit (…) use the GM module, use the GM thermal Grease (I've read of a Radio Shack substitute, but no experience with it), put the GM module on some form of heat-sink - simple aluminum bracket with some thickness to it seems to be enough, run power to the GM module via a relay with at least a 12ga. wire, make your own simple harness using metripack or weatherpack connectors (I converted the dist. to weatherpack), & use tidy wiring practices for a robust system.
Well…yeah! See HEI upgrade article and links.Quote: one of the things that I don't like about the GM modules is the exposed inductive pick-up connection. On the 8 pin modules the "external connections" (power, coil, EFI stuff, etc.) are in sealed Metripack connectors, but the two terminals for the pick-up are just tabs sticking out of the molding. These are the lowest voltage connections of all of them, and they're most exposed to corrosion! There also is nothing to maintain that connection against vibration. The terminals on the module are also an odd size, I had to look specifically for female spades that fit right.
None of this makes problems in real life. You use the correct terminals and insulators, which are readily available, you insure yourself with a dab of dielectric grease, and the connections don't corrode, fail, come apart, or get gravy stains on your necktie at Sunday supper.
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| Author: | ntsqd [ Sat Jun 04, 2016 12:57 pm ] |
| Post subject: | |
No change of opinion at all. I still don't like them. I never said they didn't work. Contrary to the greater world's current thought it is possible to have shades of gray and not be either black or white. Had I done such a conversion and had depth of experience with it my advice would have been: "Use a Dura-Spark II (blue strain relief) module..... " because then the whole 12ga. + relay thing wouldn't be required and those have a cranking mode spark retard. I do have extensive experience with the D-S II modules (I pioneered using this system to convert points dists. for International Harvester 304/345/392 engines in the 90's), but I have not used a Mopar pick-up coil & reluctor to drive that module so I'd be negligent to advise others to do so. I have experienced corrosion on those same signal voltage terminals on an HEI module that did cause real world problems with my first attempt at an I-H electronic conversion. It was much more protected than my current HEI module is. That is why I went to the extents that I did in trying to seal them off. |
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| Author: | Killer6 [ Sat Jun 04, 2016 5:10 pm ] |
| Post subject: | |
To briefly address the "it looks wrong" aspect, keep in mind when in operation, the vac. adv. will fire the spark earlier catching the rotor farther counter-clockwise on a CW rotating dizzy. Thus the rotor will come into alignment as the timing moves thru it's adv. curve. |
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