The Stovebolt Site Forums The Shop Area The HiPo Shop Need help sorting out distributor on my 261....HEI

Oh Jerry, sorry but I just cannot stop chuckling about buying a new module from “kaka part”. Lol

I may just end up running a common standard 4-pin GM module on an external mount near the coil.

Jon, that was my exact thought when I was watching the scope- the coil looks weak to me, but I’m no expert, and it’s been so long since I’ve used a scope to evaluate an ignition. I found the Heathkit scope at a garage sale for $20 last year, and haven’t had the chance to use it. Great for points ignition, but I have never used a scope on an HEI, so I don’t know what it’s supposed to look like.

I usually have an old coil laying around the garage, but it must have ended up in the dumpster, so the only way I can be sure is to buy another. I think I’m going to ditch the external S10 HEI type for a tower coil-

Any recommendations on a tower coil that won’t cost upwards of $90? What about a MSD BLASTER II?? Hoping to find one that is black and not fancy looking᠁.


I have a feeling the coil may be the problem᠁ either way, the module is also going to get replaced with a GM or better module.

The video of the scope is the last cylinder in parade mode, and you can see the scope line jutting left and right every time the engine misses..

Scope video

Thanks Jerry- I bought that one off of eBay. It’ll go in, and the Chinese one will end up in my tool roll under the seat.

There are coils like this all over eBay, Dave. This one (although the connections are slightly different) should work. (eBay auction item number 363395048933). There are others with exposed spade terminal connectors like Tom used. I think the coil he used was designed for a Mopar application.

If you ever want to sell the oscilloscope please just let me know.

So I mentioned this part (D1959) to a fellow I know and he says "Seriously, Jon...asleep at the wheel are you? That D1959 is becoming a rare duck but look for D1961. All you'll need for that old engine of yours is the D1961 with 3 pins removed and I'll show you which ones." See image below. I looked and those modules in new condition are pretty common...I bought one (NOS) for $15 with free shipping to test it and see if he's right (and I think he probably is). Besides the pins that will be left are the P and N on the left side and the + and C on the right side...just what is on the D1959.

Aha᠁I had no idea you could use a 6 pin module like that. Great info, Jon!

I will let you know about the oscilloscope. It has the original assembly/soldering instructions, the user manual, and inductive pickup.

Any coil- - - -even an OEM point type, will work with a HEI module. You just won't get the outrageous open circuit voltage the .GOV guys wanted to make up for idiots who tried to run the same set of spark plugs for 50K miles, with a 1/8" gap from electrode erosion. A clean, properly gapped spark plug will fire at <10KV, so all that extra voltage never happens anyway. The only real advantage to electronic ignition is that it eliminates the need to change mechanical points. I like the MOPAR round coil with the primary posts for female blade connectors. It looks like the original point type coil, makes 25K+ volts on open circuit, and works well with the GM modules.
Jerry

I had no idea Jerry- I thought HEI required something better. I had CDI ignition in an old Porsche and that would fry cheap coils, and the oil filled coil that I installed inverted᠁. We replaced a dead CDI box with a MSD ignition, and that wasn’t very kind to coils either᠁

I have about 30,000 miles on a Blaster II driven by a USA built HEI module hidden inside my unused voltage regulator box on the firewall. It is red, but some high-temp spray paint could fix that.

Jon G: look forward to reading the results of the module “pin reduction” exercise.
This is the beauty of The ‘Bolt, someone knows᠁ and is willing to share (and even test) these bits of information᠁..

Hank it appears both of the offers I made last night were accepted so I'll have 2 of these modules to modify and test. I'm certain it will work. As Jerry correctly said it is just a magnetic switch...at least as it is going to be used in this case. There are other features designed into the module but the 235 won't need them so I'll just concentrate on the switch portion. And I'll also have a working D1959 to compare...although the one I got from Tom Langdon wasn't marked as D1959 but had another GM number. From what I learned prowling around on the GM Parts site it was a later number shown along with many other part numbers as an "indirect alternative application" so my guess is the distributor Tom converted had been repaired once and a different but acceptable GM part was used. I should have these modules by early next week.

And along another line if anyone has a failed Pertronix unit they saved I'll be happy to pay the cost of shipping so I can do some destructive testing to see why those go toes-up. I suspect nobody has one, though. Most were probably bashed with a large rock after the person had to be towed in from wherever they were when it died.

And finally I dug out an HEI distributor I converted for use on the 235 about 12 or 13 years ago. It uses the very common 4 pin module and originally was designed to be used on the 230-250-292. It worked fine but when used on the 235 it allowed oil to come up through the shaft/shaft bore and so at last I'm going to sort that problem. These are inexpensive distributors (still being sold on eBay, Amazon and elsewhere) and they will use some GM internal parts (which may be more long-lasting). Plus you can buy a "rebuild kit" for around $30 which includes the module, a new distributor cap and rotor. This model has the coil in the top of the distributor cap. Aside from that and the lack of coil wire the main differences are two: this distributor mounts solidly and the vacuum advance only pulls the inside movement as needed and it is much larger. But as I said it did work well when I tried it.

JonG, does it have to be an inoperable Pertronix?

My son’s mustang project has a Pertronix conversion that I plan to eliminate as part of the engine swap we’re doing. It “works” as far as I know. The engine didn’t run long enough for me to determine how well, but it does make spark.

Jon, if you have access to a lathe, it would be very simple to bore that HEI housing for a lip seal on the shaft. That would absolutely prevent oil from migrating up into the pickup coil area. I'd also suggest installing a Torrington needle bearing below the seal while the housing is in the lathe.
Jerry

Jerry I wish I did have access to a lathe. That's a good idea...adding a bearing down low and one up high and a lip seal, but in this case I think I'll have to do with what I have.

On the positive side, I removed the gear, freed up and cleaned the shaft from sitting in the garage long years...sticky oil, etc. When I replaced the gear & pin, I noticed there is between 1mm and 1.2mm of free space where another washer should have been. Neither image focused correctly but there is a decent brass bushing in there...not too short, either. I'm willing to bet adding washers to the point that shaft fits snugly against the end of the distributor body will stop the problem.

JW, thanks but I would definitely prefer a Pertronix that had failed. That way I could work backwards to see why it did so.

Update on my efforts to track down the subtle, irregular engine miss/skip since the engine was first started after a rebuild: I

Engine is a 261 full flow block .060 over, with 848 cyl head (drilled for steam holes), Langdon’s “Bulldog” cam, dual Carter/Webers, Fenton intake & exhaust.

No evidence of any radiator coolant/oil contamination.

At this point, I have done the following:

Plugged the brake booster fitting on the intake manifold and the pcv fitting
Replaced the ignition coil
Replaced the spark plugs
Replaced the HEI module
Replaced the distributor cap
Replaced the distributor rotor
Replaced the ignition wires
Installed new terminals on every ignition wire
Bypassed the ignition switch
Run an extra ground wire to the distributor housing
Installed wire separators
Checked alternator output and voltage at the coil terminal
Checked all ignition system wires for any indications of chafing, breaks, bad crimps, etc᠁
Played around with plug gaps from .032 to .060
Removed the carb tops and removed all jets and cleaned all jets and passageways with compressed air and carb cleaner.
Set idle mixture and re-synch carbs
Check dynamic cylinder cranking pressures
Check all pushrods for straightness, set valve lash, and observe all valves operating at idle.
Fuel pressure was checked after the fuel pump was installed- ~4psi

The only thing that I have not replaced in the entire ignition is the pickup coil.

There are plenty of Delco Remy HEI pickup coils on Ebay, and they're very inexpensive. I usually buy several at a time when I find a good deal, as I use them in original equipment point type distributors to trigger a remote HEI module mounted on a finned aluminum heat sink under the dash, to make a "sleeper" HEI that looks like an original point type distributor. There's no law that says a HEI has to have that honkin' big housing to work right!
Jerry

That's what Ford did. Can the Ford Electronic ignition modules be adapted to HEI on the Chevy's?

Ford modules aren't quite as unreliable as Pertronix, but they probably run a close second. The old "Dura-Spark" modules that were contained in an aluminum box about six inches square were pretty rugged, but the TFI (Thick Film Integrated) system that bolted onto the side of the distributor housing was so suceptible to engine heat that they finally moved the module over to an inner fender to increase its survivability. I don't think someone could run fast enough to give me either one of those systems!
Jerry

Dave,
Briefly looking back at the thread I have to ask᠁ has the engine EVER run correctly?

When Langdon sent my Unit he provided the square coil (on his very strong recommendation), plus Packard branded 8mm Hei plug wires
, and plugs
Here is a file pic of parts he sent on the bench, taken 3/22.

Per Hotrod (Jerry) when I set it up I installed a relay & 10ga wiring to power the ignition

Dave, sent you a pm.

Chuck

One other consideratiion. In distributors where the vacuum advance moves the pickup coil back and forth to vary ignition timing according to load conditions on the engine, those tiny wires between the pickup coil and the module are in motopn constantly. Strands of the wires under the insulation can break, and cause an intermittent open circuit. That's also difficult to find, but one diagnostic procedure involves disconnecting the vacuum line to the advance unit. If the problem goes away, I'd strongly suspect broken wires between the pickup and the module.
Jerry

I will try anything at this point. I’ll check the idle without the vacuum advance connected tomorrow.

Hank, I bought the whole setup from Langdon- so I got the same coil you have, plus wires and plugs.my wires weren’t packard though᠁

The engine has never run right- it has had a slight miss from day one.

Are you anywhere near San Rafael?
I have a perfect condition points distributor on the shelf you can try᠁. Off of my 54 235 full psi engine, (don’t recall what gear is on the bottom.)
It’s not for sale but you are welcome to try it

That is the same coil and wires I got and I set mine up using a relay also.

Your lengthy list includes almost everything a fellow should consider. If you get to the end and are curious about movement of your camshaft, here is one thing I discovered back when this happened to me: A timing light might answer your question. That is to say, the strobe light might show the needle on the bell housing is striking the mark on the flywheel before and after that mark.

Hopefully that makes sense. At idle, your centrifugal weights aren't kicking in. Or that is to say, they aren't doing much if anything at that speed. And if they're providing any increase in timing, it will be small and not fluctuating. Because your vacuum advance won't be doing anything at all at idle, the timing light should show the pointer lining up with the mark on the flywheel nicely. If it is bouncing all around (advanced, retarded, occasionally on the mark), your camshaft could be moving in/out.

I paint the needle with white paint and I make sure some timing line on the flywheel is a crisp white line. Also, maybe the 5* BTC line.

Just a thought.

That "bulldog" cam has a bit of a rough idle- - - -you might be chasing an ignition gremlin that doesn't actually exist. How's the idle vacuum- - - - -stable, or fluctuating a little?
Jerry

Hank, I am over by Tahoe. I appreciate the offer- I think I know where my old dizzy is. I have to admit, I have taken the lazy route on this one᠁the old me would have pulled the HEI distributor out on the first day and found somewhere to load it into a distributor machine to check it, before I did anything else. Old age has me not enjoying the repeated disassembly of things. I used to enjoy taking things apart and putting them back together. Of course, it might have something to do with the fact that now that I am teaching, I have no surplus time or energy left over for my hobbies!

I will probably pull the distributor this weekend for a quick swap, if I can find the time.

Jon, I’m going to re-check the timing this weekend, and most certainly if I pull the distributor for a quick swap with my old points setup. Ll try to get a video of it as well.

Jerry,
you may be right. I had forgotten that the Bulldog cam isn’t all that mild of a grind. Much higher lift than the Corvette cam. Part of my trouble here might be having zero reference regarding an in-line 6. I have no experience with these engines outside of this particular engine. In the past, when we would put a performance cam that was a little more aggressive than this cam into a high compression V8 with tube headers, the feel and sound of a rough idle was very different than what I am perceiving with this engine- this one is more like a subtle, but abrupt “skip” in the 261. It could have to do with all the rotating mass the 261, compared to a V8 with a light flywheel. You can just feel it with your hand on the 261 and see it at the exhaust tip on a cold day, but no coughing, spitting, snorting, shaking like the V8. Perhaps that is the “rumble” that I should have with this cam. The skip also does persist beyond idle-it’s still there at probably around 1500 rpm. After that, it is gone, as far as I can tell. Freeway rpm feels like smooth as glass.

I’ll check idle vacuum indications again- I forgot what I saw early on in this process. I do know that the engine gives me way more vacuum at idle than I thought it would, which is nice for my power brakes.

Thanks again everyone for all of your input.

Dave

I was fighting a similar issue on my 283 that ended up being play in the distributor shaft.

Pulling the cap showed where the rotor was coming up and grinding on it. You might check for play there as well.

Checked the dist rotor vertical,okay, and also the cap- no evidence of anything amiss there. I just got my NOS GM module in the mail, so once I get the new pickup coil, I’ll pull the distributor and put those in. I did not have time to work on the truck this weekend anyway. I just heard about a guy who had a dead spot in his pickup coil. So Who knows..

It’s probably just the camshaft that I am running, but I’m going to finish going through the distributor so I can rule it out for good.

When you're ready to open up another can of worms, we can start talking about the rate of spark advance, both centrifugal and vacuum, and the fact that the 2.8 liter V6 that distributor was designed for doesn't have a whole lot in common with a long stroke inline six. Just because a pair of mules can be harnessed together doesn't necessarily mean they will make a good pulling team- - - -and the same concept can be applied to somewhat mismatched engine parts. Just force-matching parts from dissimilar engines doesn't necessarily mean they will work right without some serious tinkering.
Jerry

Jerry, I was wondering about the advance curve in that distributor. I swear that I have too much vacuum advance at the moment- that, or I need to run it as ported advance.I haven’t messed with it too much. I don’t know.

I haven’t changed the pickup coil yet, but the engine is running better now than it ever has. The slight miss is still there, but after I swap the pickup coil, if the miss doesn’t go away, I am going to accept that it is simply the cam that I have.

Over the past 60-something years, I believe I can count the engines I've seen that were designed to use full manifold vacuum on the distributor on the fingers of one hand, with a couple left over. One example was the early Chevy 327 V8- - - -1962 to 65 or so. Practically all the others use ported vacuum, with no advance at idle other than the initial spark lead set at idle speed. Ported vacuum advance happens at part throttle cruise, and goes away during acceleration, trailer towing, passing, etc.
Jerry

The Crankshaft Coalition website had an interesting wiki entry "Hot Rodding the HEI Ignition". HAD because it doesn't seem to be there today. But here it is in the archive.

Hot Rodding the HEI Distributor

I used several of those tricks on the HEI we were required to run on the "claimer" engines we ran on circle tracks in middle Tennessee. Aftermarket ignition such as Accell, Mallory, or MSD was illegal- - - -a "cost saving" concern for the "training wheels" division known as "street Stock". That class was also known as "Cheat all you want, but cover it up!" I would restrict the movement of the centrifufal advance weights by about 10 degrees, and add a orresponding amount to the initial timing setting. Then I'd grind off half the projections on the reluctor ring, which allowed the engine to rev to 7K+ RPM without spark scatter, even when using the OEM module. Since the pickup coil still had all 8 points, all the cylinders would fire. The final mod was to lock down the vacuum advance to prevent the pickup coil from vibrating and disrupting the high speed timing- - - -no need for vacuum advance on a race engine- - - -we really didn't care about gas mileage. With the above mods, my engines consistently got at least 1K RPM more than my competition, so we could gear the cars for better acceleration off the turns.

The tech inspectors were too dumb to catch those mods, as well aso some pretty extensive internal modifications that could only be found by disassembling the engine.
Jerry