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I’ve been looking at these when I’m shopping for parts and wondered what you’ll think of it.

I’ve never had one but not having to deal with points or condenser is appealing.

Appreciate any thoughts on it.

Ask 3 people and get 4 answers.

Personally I am a fan of the GM HEI systems from the late 70s/80s. Depending on your engine they can be pretty easy to set up and install.

The closest thing you will find to consensus around here is that you shoupd avoid Pertronix conversions (though there are a couple people who like them.

How often do you have to deal with the points?

Every vehicle I own with the exception of the Ford trucks has points. I never have to deal with them. The Cadillac has been my primary vehicle for 21 years. I think I've installed 3 sets of points in it during that time.

The Galaxie 500 has had the same set of points since 2011 and many thousands of miles.

Old technology doesn't necessarily mean bad technology.

Greetings. I installed a Petronix in my GMC 228. Never could get the timing right and decided to go back to points. On my newGMC 302, I used the HEI distributor.

With just a little bit of machining, the internal trigger from a GM HEI distributor can be adapted to an original stovebolt distributor housing. The control module can be mounted out of sight on an aluminum heat sink, and a MOPAR high voltage ignition coil looks almost identical to the original stovebolt coil. It takes a pretty sharp electronics guy to recognize the modifications without removing the distributor cap. DO NOT try the setup that uses a MOPAR trigger unit and a GM module.
Jerry

I don't know if it is still available but I've used Tom Langdon's mini HEI distributor (along with the square coil he sold with it) and have been happy. In fact there has only been one small problem...one of the cups that fit inside the molded plugs on the distributor cap came loose and I had to use a bit of epoxy on the bottom of the brass cup to keep it in place. Not Tom's problem at all. Took a few cents worth of product and a day for the J-B Weld to set up fully.

I do have a foreign made HEI distributor here that I converted to work on a 235 (easy conversion). I am not entirely certain where it was made...part of me suspects China but also possibly Brazil, Mexico or elsewhere in South America. Only two problems: While the engine is running, oil will wick its way up the rotating shaft and spill into the distributor (and from there eventually leak out the bottom of the cap where it connects to the distributor) and the cap is larger than I like (the coil is part of the cap). I suspect I could rig up an o-ring or something else to keep the oil from traveling up the shaft but I haven't messed with it. It could be that a rotating seal was meant to be at the top (so the shaft would be oiled) and was forgotten at time of assembly. But I will say when I used it, it operated as it should and had a good vacuum advance and mechanical advance. It was originally meant to be used on a 230 or 250 engine and I bought it around 1996-97. As I recall (and I'm working from distant memory) the connections on the dist cap were "outies" rather than "innies" (meaning old style plug wires worked with it).

Mine has only been working well for about 7 years and 35000 miles now.

Thanks for all the insights. Clear as mud now 🤭

I did warn you

The consensus is slightly clearer than mud, gm perfected Hei early on and if you can either find a Langdon converted 82 s-10 6 cyl dizzy, or convert one yourself, or follow Jerry’s tip, you will never regret it or look back. Every other unit is going to be measured against the gm Hei as it is as close to perfect as there is for our application.
If I were you I would drop Langdon a email,( he typically ?will eventually answer) and ask if he has come across any new cores to convert as he simply can’t find any any more᠁never hurts to ask.. btw- Tom Langdon is a sweetheart of a guy, you will enjoy chatting with a gm Stovebolt legend, he worked in engine development at gm back in the day.

Chuck

The later model Chevy inline six point type distributor (194/230/250/292) can also be adapted to the stovebolt engines, and converted to HEI configuration. Repair parts such as vacuum advance units, caps, rotors, etc. are more plentiful and less expensive than the early style distributors.
Jerry

I read the old tech tip the other day for a diy a conversion of an early s-10 HEI. Is that unit still the basis for Langdon’s conversion?

Early s10 6 cylinder dizzy is what Langdon used, yes, with a square coil.

I know Tom pretty well. I still have a lot of the written correspondence that he and I engaged before he retired from GM and before he took over Stovebolt Engine Company, all pre internet. If you have ever seen a list of like 4 or 5 235/261 casting numbers with corresponding combustion chamber volumes, that was a list I posted on the inliners site many years ago now after Tom and I were talking on the phone and he looked them up in the GM archives right while we were talking. He is a tremendous resource.

That being said, and I can hardly believe it myself, Tom is 80 now.

Fairly recently I purchased the last HEI that Tom had. He sold over 3000 of them over the years. Tom purchased all of the S-10 cores he could lay his hands on and there are just no more available. Originally he was modifying the shafts, but later was using custom made shafts because the quality of the cores, and in particular the shafts, was becoming an issue.

So it’s not likely any more new “Langdon” HEI units will become available. And I imagine that at some point, Tom will likely want to hang his spurs up. it’s probable that if you keep your eyes open, a used unit may come up for sale.

As for Petronix, it’s just a different way to trigger the coil. Works essentially like a set of points. Some who have used them swear by them. Others, have not had a positive experience with them. But the thing is, a Petronix converted distributor is not a high performance ignition.

On the other hand, an HEI is, and is probably one of the very best designs ever. If you really want a good reliable non-point ignition that uses modern parts (relatively speaking, lol) available without a lot of fuss or muss, I think you would be hard pressed to find a better ignition.

As for converting a stock 235 distributor to HEI, I know that Jim Linder at Bubba’s Ignition use to do conversions. What I don’t remember is whether his was a Mopar trigger and gm module or gm trigger and module. Jim is either very semi retired only doing flat head ignitions, or he is completely retired. He had been recently beset with some unfortunate health issues so it would not surprise me that he has fully retired.

Deve at Deve’s Technet I think still has his kits available using a Mopar reluctor, GM trigger and GM module, along with a plate that installs over the original point plate. I have Deve’s parts to do a conversion, just have not had time to actually convert one but if his YouTube video is any indication, it works pretty good.

Deve's kit uses a Mopar trigger. I have one.

Dragsix,

I don’t understand the comment about the lack of S-10 cores. I could buy at least three different makes of reman 2.8 S-10 Dizzy’s right now on RockAuto. Is there something more specific that is needed?

I checked Rockauto and JW51 is right, as I found three remanufactured distributors. I also found a list of applicable vehicles. This might increase the chances if finding a core in a junk yard to convert. If you did locate one, I would call Tom Langdon to see if he would convert it for you, as I’m pretty sure he would.

ACDELCO 88864746 Distributor

Why not just convert a brand new one? Who needs a junkyard?

Incidentally, the tech tip here speaks of a 1980 S-10. I don’t think an S-10 existed in 1980. Probably just a typo?

Yes, 1981 was the first year for S-10s.

Has anyone else actually done the "small HEI" conversion? I have, and it's not simple or easy. Unless you have a lot of machine tools and several years' worth of experience using them, it's not something I'd recommend trying. It involves shortening the housing, fabricating a shaft extension to drive the oil pump, and changing to a different drive gear. I started with a third world clone of the S-10 distributor and spent several hours in the machine shop modifying it. Then I trashed the no-name electronic parts and bought "new old stock" Delco-Remy items to replace them.

Here's one to start with, if anybody's up for the challenge

www.ebay.com/itm/133580523350?

Jerry

I am just repeating what Tom told me. He said he can no longer get cores. My guess is that Tom was not making these up one or two at a time so I imagine he was not looking to buy cores one or two at a time. Just my own guesswork of course. That and what is unsaid, he is 80 now. Would he build one if he had a decent core, the custom shaft he used, and other parts, I don’t know. My sense of it when I purchased the HEI was that mine was the last he had on hand, and the last he was going to have on hand. But ya know, ya never really know, lol.

So Jerry, what is the issue with the Mopar triggered HEI? They seen durable enough.

T-Doug GM HEI,s re-worked to fit our 235/261 application work fine for me,no relay,not a computer controlled type. Some running for 25 years. I find a coil in the cap type buy about 5 $ worth of stuff at the farm store and do all the work at home. Have 6 running .

Mostly the source of the system, and the fact that the trigger assembly and pickup are getting extremely scarce. The MOPAR six that used that electronic trigger was only in production for a very limited time, and finding parts if they're ever needed will be almost impossible. There's also a few proprietary parts used in the conversion that might be impossible to obtain from the local FLAPS if they're ever needed. There were literally millions of the GM bits and pieces manufactured, both OEM and replacement parts. They're dirt cheap on Ebay.
Jerry

The “big auction site” has quite a few options for a small cap HEI distributors for the 216/235. Price is $150-$200ish. I suspect they are of very questionable off-shore origin.

Can anyone tell if they are based on the S-10 design or something else?

I was just wondering if a guy without a lathe could buy one of these, swap in some better OEM internals, and have a decent outcome.

(This is just a curiosity. I’m content with my points ignition and no plans to go HEI any time soon).

I got one way back...late 90s. Not a small cap style at all. Don't know where it was made...either China or maybe Brazil or elsewhere in South America. A friend believes it was from Germany as parts of the box are printed in English and German. The distributor itself is not marked anywhere as to country of origin and that's why I suspect other than China. The fellow thinking Germany could be right. Coil in cap, not really a copy of the S-10 design. In my opinion it is a modified copy of the HEI made for the 230/250 and I believe it uses GM parts or copies of them. Can be adapted to the 235 (which is what I did with the one I got using the original 235 distributor mount scheme). You need to shorten the shaft where it connects with the oil pump a bit and grind off the 230/250 mounting flange to let it drop into the block further. Good vacuum advance, unit works well enough, is larger than I would prefer but the size isn't unmanageable. Two things: the plug connections are "outies" instead of "innies" so you can use the original type plug wires and mine is lacking some sort of oil seal. But it did in fact make a doggone hot spark and it didn't have any notable operating problems other than the oil leaking. As soon as it cools off here I'll try some o-ring seals and other seals and re-mount it on the 235 and see what happens.

Morning all,
In reading through this entire thread, it appears that the info is strictly for Chevy applications. Does anyone have information for a 270 GMC distributor conversion or will what have already been said work the same?

Thanks
Phil

Saw Mill If you make your HEI distributor the same mimensions as your GMC take-out it will work,watch for interferance where the big HEI is close up on the side of your 270. I use the coil in the cap type for simplicity and so you could have a spare under the seat for the road. I think that on disassembly you'll find sludge on the HEI shaft makes it hard to get apart,once it's out you can clean it up. Then do your magic,once running it's great. Those GM engineers are pretty sharp !!

6 cylinder Chevy distributors from the 50s (and maybe earlier and later) and GMC 6 cylinder 228/236/248/256/270/302 distributors from 1939 to 1962 will physically interchange. I have a 55 Chevy distributor in my 52 GMC 228.

Just a few questions on the "large" 6 cylinder HEI conversion. Did you completely remove the distributor mount/stop circular boss on the housing and then put the 235 adapter over the slick housing? How did you determine how much to take off the bottom of the shaft that drives the oil pump? Any other tips? Thanks!

Yes, that is what I did. I ground the circular boss and then filed it smooth to get it to the same diameter as the AD stock distributor and used the stock 235 mounting bracket. Then to determine how much to take off the bottom of the shaft that drives the oil pump I did two things. I first measured the AD stock distributor to see what had been allowed there and next to be certain I installed the stock distributor into a block which had a camshaft and oil pump in it to see if I could tell where the OEM distributor gear mated with the camshaft gear (which as I recall wasn't quite as easy as I had hoped it would be) and went with that. It worked fine after I finished...aside from an oil seal I think was missing when I got it. Here is what I wound up with: oil pump driving tang is .454" from the shoulder to the end (the distance between the red arrows below), distributor mounting piece is 4.885" from the tip of the oil pump driving tang up to the bottom of that piece (distance between the two blue arrows below) and the shaft diameter is 1.05" (distance between the other two blue arrows below). Hope this helps. Please let me know if you need more info.

texczech You can do it either way,I don't like to cut the collar off if I can avoid it. Last one I done was out of a 77 chevy pickup,took the gear off put on a .030 thick hard washer then reversed the gearput it back on and re-drilled the shaft thru the original hole in the gear. End up with a little slack up and down .010 would be fine. Then make an oilite bronze bushing to ride on the oily block below the gear and lastly make a stub shaft to reach the oil pump. Iv'e never done one with the clamp-on collar but others like it . Early on I just got an oilite bushing from the farm store 3/16x 3/4 roll pin 3/32x 3/4 roll pin to hold stub shaft pinned thru the flat at the bottom of the upper shaft and thru the bushing. Important that the hold down doesn't clamp the assembly down tight to the block should have some slack up and down. The oilite bushing was 1-1/8x3/4 1/2 inch bore if you saw it apart right in the center may have to shorten a little. The 2 shafts may be .012 smaller than 1/2 inch lets you get it stabbed.

One thing I forgot to mention...unlike the original AD distributor advance, this unit will be completely stationary when installed. Any spark advance will be either mechanical or from vacuum but the whole distributor won't move back/forth as it used to do.

I make a pinch clamp from 1/4" thick by 1 1/2" wide aluminum flat bar instead of using the stovebolt bracket. It does the same job.
Jerry

So, basically by installing the 235 holddown mechanism on the modified housing at the proper location, there was no need to "modify" the drive gear or the oil pump drive tang in any way?

texczech Lay your old take-out distributor next to your HEI see if the gear lines up,see if oil pump drive reaches oil pump,be sure your not clamping down too tight and your ready to go. I never saw one of these leak oil into the cap as someone else said they had,however I never have my cap off much cause it's running.

No, that isn't the case because the tang which drives the oil pump is too long and it will make the gear mate incorrectly with the camshaft if it isn't trimmed. I used the 235 holddown mechanism because I had it handy. As Jerry mentioned, you could make a pinch clamp from aluminum. The important thing is to be certain the gear which is driven by the camshaft mates as it was designed to. As fixite said you can see the difference if you compare the old (OEM) distributor to the HEI unit you need to modify. When you do that you will notice the OEM distributor was designed slightly differently. The part of the shaft that becomes the tang is radiused whereas the one on the HEI unit may be straight cut. Not a problem at all, but just a difference. As I said the main thing is to get the distance right so the gear won't be running too high nor to low on the cam drive. If you don't have an original distributor to compare, please let us know. I have one here I can take images of.

I'm the person who mentioned the oil problem. And the one I have definitely did that which was why I stopped using it. But in fairness I bought Tom Langdon's unit and haven't spent any time trying to figure out what the problem is with the other one I own...a project for a cooler day.

Just getting rid of the points was not enough for a control freak like me.
So I got me a 123 Ignition (Dutch company), and have them put it in a new Mallory dizzy (but they also can do it with your original housing).

It not only replaces the points, but you are able to put in any advance and vacuum curve you like (and some more stuff), straight from your phone without even lifting the hood.
The first unit I had still needed a laptop and a USB cable, now it's all Bluetooth.
This goes way beyond anything you could do with adjustable advance canisters and toying with weights and springs.

It is quiet interesting what curves you can do, with a hopped up 261 and the gas we have today.
I feel that I now can give the engine exactly what it wants, instead of what I thought it needs.

And on top of it - it's totally invisible, you really have to pop the dizzy cap to see it, otherwise it looks totally stock - no blackbox, no exotic coil etc.

Frank

Post pictures of your setup , Frank.

Frank: you have mentioned them before and I looked at their offerings online, but they don't appear to offer anything for these engines.

Do you know what model/setup you are using?