The Stovebolt Site Forums The Shop Area The Electrical Bay HEI conversion to coil in the cap

Found a 1975 remote coil HEI in my pile,have one truck left with points so went to flaps and my counterman ordered in a fresh wiring harness and cap to make a nice neat HEI one unit outfit. Next step is to make a stub shaft to fit oil pump drive,along with extended bushing to support iron distributor gear. More later.

No need for a stub shaft, just turn HEI housing on lathe and use the Speedway hold down bracket #91044030. Done dozens.

coilover Will check that out,have several different hold downs running now. I think this one can use sbc v-8 hold down. What is your take on relay to protect original ignition switch it's a 1948 2-ton. I think my 5 that are running all have original GM modules in them. Never even heard of switch trouble till now. None of mine have a no. 10 wire to the HEI either and some are 25 years old. This one has a stub shaft,more info on turning it please,thanks for the reply. Also have used several v-6 junkyard versions that ran fine.

coilover Guess you haven't seen my request for a little more inside info on turning the HEI in the lathe,as you said.

I had to re-read your post several times to find that request when I went looking for it.

You will get better feedback and answers if you use proper sentences/grammar. Using line breaks to separate out thoughts can also be very helpful.

If you like, I can help edit your post above for readability.

Fibonachu Thankyou for the reply. My english teacher wasn't too impressed by my work either. I was just hoping for more info on the lathe turning you suggested in your first reply. I don't see how this distributor will reach the oil pump tang without that stub shaft. I read somewhere that the distributor gears were the same since 1937,then I see some steel cams (not cast iron) so i've never hit that problem yet. I think this distributor will fit right in the block and can easily be clamped down with a v-8 hold down.

Fixite, Coilover (Evan) posted about turning the distributor on a lathe to get it to fit.

Could you post a picture of the distributor your trying to use? That would help us understand what your trying to do and maybe others would be able to help.

coilover Ended up reversing the distributor gear with a .030 shim washer above it,made an oilite bronze spacer to ride on the block below the gear. Then roll pinned the spacer and a .375 longer stub shaft to end up the same dimensions as the distributor I took out. HEI housing is the same diameter as the original distributor,so a perfect fit. Thanks for your input on this.

Phak 1 Got my HEI all sewed -up ,see the explanation above,these make the best ignition I know of cheap,easy,GM all the way! Thanks for your input on the project. Only thing left is to adjust for end play up and down so the rotating shaft isn't clamped tight by the hold down.

A picture would tell a thousand words and help future ‘bolters that would like to do the same conversion.

Wouldn't it be simpler and involve a lot less effort to just put the HEI pickup coil and reluctor into the original distributor housing? The trigger module can be mounted anywhere as long as it's on a heat sink to prevent it from overheating, even under the dash, out of sight. A Ford or MOPAR electronic ignition coil looks almost identical to the one used with a point type ignition system, and it still produces the 50KV+ open circuit firing voltage that the big cap HEI coil does.
Jerry

Hotrod Lincoln I am seeing your point on using HEI parts in an original 6 v distributor,have a pile of Hei goodies out there. Will look at the possibilities in trying to manufacture one those,can't think of the picture of the shaft with rotor just yet without looking at it.

'Bolter Deve has done this using a mid 70's Chrysler six reluctor wheel and pickup in a tall cap Chevy distributor, an externally mounted GM HEI module and a Blaster 2 coil. I've had one of his kits on my '52 GMC 228 for about 35000 miles in 8 years. Works great.

Bill Hanlon Thanks for your reply,is there an article on Deve's build ?? I have used several different in-line and v-6 HEI's to do this conversion and they are all running. The trouble with the HEI's that have to be turned down that I see is they get pretty thin,can't recall if I have any of those running out there. Seems like once you get it fired off it'll run a long time,mine are all just used parts. Maybe Deve will chhime in on mopar parts.

I posted my experience when I did the install over here. It includes a link to Deve's kit.

Bill Hanlon That is interesting HEI reading have to go back and study the details. Thanks for the reply !

That MOPAR setup is obsolete, and very difficult to find if a part ever needs to be replaced. GM HEI stuff is plentiful and cheap, and can be adapted much easier that Deve's Rube Goldberg system.
Jerry

Show us Jerry. Include any machining costs for those of us that do not have that knowledge or equipment. RockAuto's price today is $22.79 for the pickup and $3.19 for the reluctor. The reluctor would need machining, but given that it is just a lump of metal I don't see how it could go bad.

Actually, since the reluctor is just a piece of steel, I use a triangular piece of metal that aligns with three of the pickup coil points as it rotates. Attach it to the point cam with machine screws, or even braze it on. Then align the pickup coil points to coincide with the rotor position when it lines up with the distributor cap connectors. The pickup still triggers six times- - - -just with half the induced voltage of the 6 point reluctor. That's a trick we used on racing HEI systems when the track rules wouldn't let us run aftermarket systems like Mallory or Accell. I would grind off every other reluctor tit, leaving four on a V8 distributor. MY HEI systems would hit 7K RPM without spark scatter when a stock system would barely make 5500. The tech inspectors never could figure out what I was doing! I even had a fake vacuum advance system in place.
Jerry

Waiting for details of your better solution Jerry.

Coming soon- - - - -having some health issues that are keeping me out of the shop right now.
Jerry

Bill Hanlon I looked at the build on the reluctor system,it's a lot simpler to make one bronze bushing,drill 2 holes ,make a .375 longer stub shaft and keep the ignition all in the distributor. Could keep a whole unit under the seat for road trip security,plus have the big HEI cap like powerful ignition should have. Cost was about 5$ for parts. An HEI from the woods junkyard was 50 $ tested to be sure it was alive. When onlookers see that HEI they say OH. Welp gonna go truck not fight it all day !!

First, I'd like to apologize for any bad feelings I have caused. I'm just trying to learn and I get frustrated when I don't understand what you guys are trying to tell me. No bad vibes were intended.

I'm going to take all of fixite7's HEI modification comments and see if I can put them into terms that I can understand. I hope that he will correct anything I get wrong and add detail where necessary.

A picture of the distributor with the stub shaft and bushing in place might answer some of the questions below.

Any measurements I give below are using my beat up Harbour Freight micrometer and should be taken as +- a few thousandths.

Any measurements were taken on my 302 GMC block and the short cap distributor (GM part # 1112362) from the GMC 228 in my '52 truck. Same number is listed for use in '52 216 Chevy engines. I know the Chevy and GMC distributors of this era interchange. The current distributor in my 228 started life in a late 50s Chevy 235.

fixite7 said: Found a 1975 remote coil HEI

me: What vehicle(s) would be originally equipped with this distributor and coil? What do I look for in a junk yard?

fixite7 said: Next step is to make a stub shaft to fit oil pump drive

me: Does this stub shaft have a slot on the top end to mate with the tang on the distributor shaft and a tang on the bottom to engage the slot in the oil pump? How long is the stub shaft? Is it the same diameter as the distributor shaft?

fixite7 said: extended bushing to support iron distributor gear.

me: Does this bushing cover the joint of the distributor shaft tang fitting into the slot of the stub shaft?

me: How long is the bushing?

me: I assume the ID of the bushing is just a few thousandths larger than the distributor shaft, right?

me: What is the OD of the bushing?

fixite7 said: Ended up reversing the distributor gear with a .030 shim washer above it

me: I assume this is to move the teeth on the gear further down into the hole so they will line up with the gear on the cam.

fixite7 said: made an oilite bronze spacer to ride on the block below the gear

me: Is the purpose of this spacer to provide a positive stop at the proper insertion depth for the distributor?

fixite7 said: roll pinned the spacer and a .375 LONGER (the caps are Bill's) stub shaft

me: Both the spacer AND the stub shaft are pinned to the distributor shaft?

me: The .375 is how far the stub shaft sticks out of the bottom of the bushing? If the bushing rides on the bottom of the hole in the block that the distributor plugs into, the tang of the stub shaft would need to stick out of the bushing a little less than 1.948" in order to fully engage the slot in the oil pump shaft. I do not understand the .375 measurement at all. .375 longer than what??? What is the total measurement from the bottom of your bushing to the tip of your stub where it goes into the oil pump shaft slot?

me: The shaft diameter of my distributor is 0.488". I assume that the shaft diameter of your "stub" is near this measurement. The hole at the bottom of the cavity in the block that the distributor slides into is around 0.500". I don't have a way to measure that hole directly, but a 1/2" drill bit is a pretty snug fit.

Sorry for the long post, but I'm just trying to understand what is probably a pretty good idea.

Bill Hanlon OK lay an original 235 distributor out on your bench. Make your 1975 chevy pickup in-line 6 HEI the same dimensions as the 235 distributor. I took the distributor gear off reversed it put on a .030 shim washer above the gear and left some up and down "slack".030 would be fine. Next since I don't have a 21,000$ Bridgeport mill I carefully drilled a 3/16 ths. hole thru the distributor gear hole and thru the shaft for a 3/16 ths. roll pin. Next buy an 1-1/4 x 3/4 O.D. oilite bronze bushing at the farm store,usually in the yellow boxes about 3$ get a 3/16 by 3/4 long roll pin and a 3/32 by 3/4 roll pin 85 cents. Now below the distributor gear saw the bronze bushing in half ( or maybe shorten it to be the dimension of the 235 distributor from the block surface to the bottom of the gear.) This half bushing then pins on a stub shaft that is 3/8 inch longer than (.375) the original stub shaft so it reaches the oil pump. Measuring from where the 235 distributor sets down on the block to the lower end of the oil pump tang is 4 15/16 inches,same as the 235 distributor. The .488 shaft will not be a close fit in the bushing below the gear no problem there main thing is to not clamp the assembly tight with the distributor hold-down. The thrust area on that bushing is just flooded with oil. Use an old shaft with a tang already on it cut to length then grind ( or hacksaw a slot in it ) clean up with a file and pin thru your bushing to hold it on there stab it and check your up and down clearance. Your drilled hole should be thru the flat of the tang for the 3/32 roll pin. Mine is laying out on the tail gate PM me a phone number and i'll send you a picture. It's the best thing I've done for these tractor engines !! Oh Bill don't worry about bad feelings,someone commented about raw cheeks from comments on stovebolt,I nearly fell out of my chair LOL LOL it's all for fun with GM trucks !!!

Thanks, I think I pretty much understand now. PM with phone number is on the way.

When searching for HEI 6 cylinder distributors, make sure and get an even fire one, odd fire will not work. ID by observing all terminals are same distance apart. Cannot just switch caps!

Ed

That's why I asked fixite7 for a make/year model/engine size to look for in the junk yard.

Looks like one that would qualify is a '77 Malibu with a 250 inch engine. Probably lots more.

The odd fire distributors were used on early 231 cubic inch V6 engines- - - -not on any of the inline engines. The only modification needed on the 230/250 HEI distributors, either coil in cap or remote coil types, is to make them drop into the stovebolt block a little deeper. That's accomplished by machining (or grinding) the locator flange off the HEI distributor housing and replacing it with a 2-piece shaft collar. Then a clamp bolt into the original hole in the block for the point type distributor allows the ignition timing to be set. It's not necessary to do a lot of tinkering with the shaft or the gear. The locator flange on the HEI housing doesn't quite let the tang on the shaft engage the oil pump correctly unless it's machined off to allow the housing to drop into the block a little deeper.

Once I find the time to document the pickup coil and reluctor swap into an original distributor, I'll write a tech tip on what's required to keep things original looking. The HEI module can be mounted out of sight to give the appearance of an OEM distributor.
Jerry

I put my HEI module inside my unused voltage regulator case. Signal wires from the pickup in the distributor are twisted pair with a shield grounded only at the module end. All wiring is covered in heat shrink tubing to look reasonably stock.

fixite7 sent me this picture and said it was OK to post it here.

It leaves questions in my feeble mind.

1. Does the roll pin in the brass bushing go through both the stub AND the tang of the original HEI shaft?

2. Is the stub shaft .488" diameter like mine? If so, what keeps it from wobbling around in the .500" ID of the bushing?

Bill Question1 Yes it's OK to drill that hole right thru both shafts,I usually just put a piece of wire in there until I get the length just right,you'll have to face the bushing till it gets clearance so you can move it up and down. Not much just free so the hold down can clamp the distributor in the block. Once again if you don't have a lathe handy you can file it off,put the factory end of the bushing down where it can ride on the oily block. Question 2 Yes my .488 shaft is not a close fit in that bore above the oil pump,you need clearance to get it stabbed and once it is in there it can't get away and is well lubricated by oil splash. I don't like to cut the factory made on there hold down collar if I don't have to. That method would work just fine though too. I have one (out in my fleet ) where I just silver brazed an extention on the very bottom of the pump tang to reach the oil pump,kind of questioned that but it has run thru heat and cold. Figured if it failed it would be in cold weather when the oil is thick and hard to move. The .500 I.D. bushing is really just holding that upper tang joint in place but it is supporting the gear. So Good Luck with your build this makes 3 or 4 different versions so far. The leftover 1/2 bushing is just right to do another one,just need 2 more roll pins and a piece of shaft.

We've been adapting these distributors to stovebolt engines for years- - - -just cut the shoulder off the housing and drop it down into the block another 1/2 inch or so by using a shaft collar with a setscrew- - - -no gear or shaft modifications needed.
Jerry

Jerry: That sounds like the simplest solution to me. If I didn't already have my HEI working I think that's how I would put one in.

The point type distributor for the 194/230/250 six can be adapted to the stovebolt engines with a similar procedure. It's a bit more complicated, but not much.
Jerry