Looking for a source for a few HEI distributor parts.
One piece in particular I'm looking for is this:
20250107_160152.jpg
This goes under the pickup coil to keep the grease in the reservoir around the upper bushing. It's not much of a part, but very necessary.
Another thing I'm looking for are new centrifugal advance weight pivot pins. On the early HEI distributors they are serrated and pressed into the top of the reluctor piece. I don't have a picture of this though. I'm not sure if they're even available. I've been looking at the pins from a points distributor, but those are not serrated, so I'm not sure if they'll work.
But does anyone know who sells these items?
Thanks for any help you can offer.
Rick
Early like meaning 75 or earlier? Those were quite different than most of them and seemed to be more prone to getting stuck than the common design. I wonder of a place like Performance Distributors still rebuilds them? They have got bigger so maybe just sell stuff now?
Performance distributors? I'll look into them. Thanks. I wasn't sure exactly where to look to be honest. I know that the GM parts system is not going to have anything anymore. They've purged all the old stuff years ago unfortunately.
I'm working on a few Cadillac HEI distributors. I've got 2 1977, and 1 1978.
Been trying to figure out what parts will get me a specific amount of advance, but there's only about 150 different center plate numbers, and probably just as many counterweight numbers, and I've found a couple of threads on other forums about these, but they don't list all of the various combinations and their parameters.
I'd love to find an AC Delco parts book specifically for distributors. I have one for carburetors, but even it doesn't have enough in it to cover everything.
But I don't know where else to look for that information.
I tried to compare apples to apples by checking the 77 service manual and the 78 supplement, however Cadillac decided to change the specific rpm specs from one year to the next, which makes that virtually impossible.
Even the vacuum advance specifications are different between the two years, so a comparison is not possible.
Another confusing thing about the specs is that they are listed for distributor rpm, not engine rpm. It's not a big deal, just have to remember to double it for engine rpms. But everything is related, or tied to the distributor rpm, the centrifugal advance settings and the vacuum advance.
I honestly think the GM engineers didn't want anyone knowing what was possible or what was going on, because you can't find out any of this except for what is provided in the service manual for a given vehicle.
You can't see the whole picture.
Does anyone have a Delco distributor parts book that might shed some light on this?
Thanks TJ, I appreciate your input.
Rick
That should be the common design that was used till they went to fully electronic control.
I would agree that somewhere there is or was a book that said dizzy 1234-5678 as listed in the service manual gets the 123 springs out of the GM parts bin and the 456 cam and 789 weights.
I would imagine the people that made distributor machines must have had some sort of reference book with some sort of parts cross reference along with the specs. Maybe that would be a research path?
Performance Distributors used to be known as DUI Davis Unified Ignition. Davis was I think a Ford guy that liked the HEI so hacked an HEI into a Ford and it grew from there.
That seal really looks beaten. If you have spares,
it could be stolen from about any Used or rebuilt
HEI of the era. I have used a rebuilt Olds HEI as
a new parts source for the 76-79 Seville HEI.
There have been rebuild kits that put an oversized
plastic bushing over a badly worn steel pivot,
along with weights with oversized pivot holes.
Good luck finding the exact replacement weight and
center plate replacements. I have no faith in any
rebuilding operation providing more than a generic
one-fits-all part. I have seen functionally identical
parts given different numbers because of a cosmetic
change, or maybe just a year change. Just maybe a
replacemnt timing chain is more important than yearly
HEI variations on the same engine.
The General is not interested in giving more than
the minimum info to buy parts for late models from
the dealer. Older stuff is not supported as they
would rather sell you a new car.
good luck, Bruce Roe
I have an idea that maybe a felt washer might work in it's place, not sure yet, gotta try it and see if there's enough room for it.
I tried to get it out in one piece by using compressed air from the bottom of the housing and blocking the top of the upper bushing, but it wouldn't come out, leaving me to poke a screwdriver through it.
The heat over the years just cooked it into a biscuit. Just touching it little pieces would come off.
A distributor machine would be really nice to do testing with, but I don't know anyone who owns one, and haven't heard of or seen one for sale. That's one of those tools that you might use once every 10 years, so I'll test them the old-fashioned way, on the engine.
I've heard the horror stories about aftermarket weights breaking up and taking out rotors and caps. I've found a couple pairs of them in my collection of distributors. But I think most of the problems are with using them in a race motor.
In a street-driven car they'd probably wear out quickly, but I'm not going to try it anyway. Neither set was marked as to what they were, meaning like GM did with theirs.
I've got 9 or 10 different ones in various engines around here, and I went through all of them and wrote down what each one has in it, so if I can find a list of what does what, I can build the one I want.
TJ, I've heard about grafting an HEI onto another brand of distributor, I was even thinking about trying it once for my old GMC 305E V6 I used to run back and forth to work, but it wouldn't have made much difference in the mileage, that thing got 10mpg up hill, down hill, empty or loaded. Even adding an overdrive only brought it up to 13mpg. It did make it last longer though.
Thanks for your input gentlemen, I do appreciate it. You wouldn't happen to have, or know someone who does, an AC Delco distributor book would you?
Rick
I don't see GMC on their list but ya wanna put an HEI on your air cooled VW? Got a Scout that needs an HEI? Pretty wide range. I think initially they could have been a little on the hack side but it didn't take long before they started fully machining them from scratch on their own.
I do see the machines come up from time to time for sale but they are not small and I don't know really anything about them so with my luck the ones that seem not crazy priced are missing some critical parts that you need to make em useful.
I used to see an add for someone with a machine that did work in my area but have not seen it for a while and its either gone or have not guessed the name close enough for him to come up on a search.
Well I checked out Performance Distributors, they don't sell any of the advance curve weights or related hardware, claiming that they cannot guarantee that you'll see the results you want because they use a distributor machine to set up their products, which to some extent I would agree. But you would think that after doing this for as long as they have, they should know what the results will be from a given set of parts.
I'll keep looking for a solution, it may take a bit longer than I hoped, but I will figure it out if I have to test every combination of parts I have in stock.
I was really hoping to find a listing for the various combinations with the related results, but so far I've only found limited test results for just a few specific parts, which would be nice if I had those particular parts on hand.
They tested the 139 weights with a big selection of center plates and posted the total advance for each pair.
I'll just have to find some more old distributors for parts and hope that they aren't too worn out to use.
Thanks for the suggestions and input, much appreciated.
Rick
All the weight kits I have seen available in the last 20+ years have looked like crap. Really crude stampings with rough edges. If its wear in the pins that is your issue you could likely buy bushings from a place like McMaster Carr so the only trick would be oversizing the holes in the weights that you have. Drill bit even in a press with vice would not likely preserve the centering of a worn hole and I would think the position of that hole is part of the puzzle. End mill would be the tool which you could use in a drill press if you could get it aligned and clamped.
Most of my HEI distributors have the small diameter pivot pins, and they are in good shape. But I have 2 that have the large diameter pins, and one of these has both pins worn more than half way through, which I doubt a bushing would fix, at least not for very long.
On the small pin weights, they usually have a plastic bushing, but I've been replacing them with a brass one I've been making from a piece of brass tube. I have to drill out the center to match the pins after I press them in and cut off the excess. I've done 4 sets like this so far without a problem.
It's the large diameter pins that are the problem, I'm not finding any.
I did remove a set from a point-type distributor, they're just slightly bigger around but the length is the same. The problem is installing them. You can't very well turn them down to the necessary diameter, and the original pins are serrated. You can press them in, but you'd have to spotweld them on the bottom to make sure they don't come out. And pressing them in isn't easy.
That aside, I'd still like to get a list of what the various center plates and weights will yield as far as maximum timing advance. The springs are another factor, but I can test those easily enough.
Rick
WHAT IS THIS DISTRIBUTOR GOING INTO YOU ARE TRYING TO PIECE TOGETHER? I have the seal, and the correct upper bushing lubricant you need , GM did not use grease, they used a oil impregnated media which i have. I rebuild and recurve distributors & have four working SUN dist machines. Many years ago I purchased from a Delco Remy distributor engineer his dist parts inventory in Anderson IN. I have 110 different advance cams ,weights & springs for HEI dist. Also Delco ignition points & new tested condensers, & weights & bushings for point distributors. But no longer have new weight pins. If you send me the dist numbers & date codes off the dist & year of Cadillac I can look them up in my Delco books or SUN spec cards and tell you what the stock advance curve should be. The parts most susceptible to wear on the HEI are the weights & pins on high mile distributors and then the shaft & bushings. It would be cheaper to find a used dist in good condition than repair a worn out one. As far as setting up the advance curve on a dist, it's much easier & faster with a dist machine than in the car - been there done that 50 years ago. In my experience the serrated pressed in small dia pin was used in 1975-76 Chevys with a Nylatron { plastic } bushing through the weight & onto the pin. and was prone to wear out & then wear into the pin. Oldsmobile Pontiac Buick Cadillac used a larger diameter swedged in pin with no Nylatron bushing. Springs are different lengths and wire diameter to provide the proper advance at the correct rpm. If you don't know what you have, you're taking a shot in the dark attempting to set one up.
Well, that's a lot of questions, where do I start?
One of these is going into a '69 472 that I'm installing into my '56 Coupe Deville. I'm also using the TH400 and the rear axle assembly from a '72 Cadillac.
I've got 3 Cadillac HEI distributors, 2 from 1977, one from 1978.
I tried comparing the 77 and 78 service manuals to see what they were doing and to see what might have changed between the two years, but the specs used different parameters, making that very hard.
However, the one I'm currently trying to set up is actually in my 1988 Suburban with a 350 and a Quadrajet now.
I lobotomized it after the roller cam didn't want to play nice with the ECM and TBI.
I'm using an air/fuel ratio gage to set up the Quadrajet, and because I use this for towing, I wanted to set up the distributor as well.
I replaced the original computer controlled distributor with the HEI.
I've been reading a lot about this on another forum that you've posted on.
I'd love to pick your brain if you wouldn't mind.
I have at last count, 10 normal HEI distributors, and probably another 6 or so of the ECM controlled 7 pin HEI distributors.
But on the Suburban I'm trying to get away from using a computer. The lobotomy has been successful, I just need to fine tune everything now.
It runs great, but I'm still in the middle of adjusting the carburetor.
But before I run it hard down the road, I wanted to get the distributor set up as close as possible.
I want it to have max centrifugal advance of 36 degrees around 2800 to 3000 rpm.
I've put together a way to test the vacuum advance cans using my A/C evacuation pump, a vacuum gage, and a control valve to adjust the amount of vacuum to the advance unit.
Screenshot_20250109-193309_Gallery.jpg
Screenshot_20250109-193120_Gallery.jpg
Then I write the start vacuum and full engaged vacuum readings so I know what I've got in stock here. Then I can use the one that gets me the closest to my goal.
I sent you a PM as well when I saw your post here.
Thanks for speaking up here, I definitely appreciate it.
Rick
Ok, the 2 1977 distributors are number 1103217, and the 1978 is number 1103332.
The 77's have a #422 center plate, and #53 weights.
The vacuum advance is number 584 with a 28° range.
The 78 has a 444 center plate and 139 weights, and a 584 vacuum advance with 28° range.
I haven't tested any of the vacuum advance units on these yet, I just made the setup to test with today, so only checked a couple of units I had laying loose.
I forgot to add the 3 HEI distributors that are in vehicles to my total, so I've actually got 13 normal HEI units, but I've still got to get the numbers off of them.
I will eventually get the ID numbers from them as well as the numbers on the weights and centerplates. That way I'll know what I have to play with here.
The numbers on the other ones are as follows:
1103246, 1977 350, (2 ea.) 1 has #368 centerplate, #106 weights and vac can #517-18°, the other has aftermarket center plate and weights, and vac can #693-16°.
1103358, 1978 454, #402 center plate, #106 weights, vac can #517-18°.
1103376, 79-86 454, aftermarket center plate and weights, vac can marked #57 with no other markings. This one was worked over by someone before I got it.
1103465, 82-86 350, #368 center plate, #106 weights, vac can #614-20°.
1110754, 81 229 V6, #482 center plate, #60 weights, (but pins and weights are worn), vac can #644‐16°.
1112940, 75-76 350, #469 center plate, #60 weights, vac can #691-20°.
The springs I've got are just what were in the distributors. No real way to identify them that I know of.
Rick
Quote from: Suntuned on January 09, 2025, 07:49:49 PMI have the seal and the correct upper bushing lubricant you need, GM did not use grease, they used a oil impregnated media which I have.
I wondered what that stuff was, I thought it might be really old grease but I never suspected it was something like that. I tried taking it out and maybe reusing it, but it didn't look right, so I've just been using a small amount of wheel-bearing grease instead.
I noticed that the upper bushing has a couple of holes in it I'm guessing to allow oil to get into the reservoir, but I didn't know for sure.
I have a felt washer that fits perfectly in the spot where the plastic piece goes, and figured if I couldn't find the plastic piece this would work.
20250109_194136.jpg
Rick