HEI conversion

[tincan1966]

we use the Pertronix units alot in our shop, but there are alot of choices. I am assuming the main drawback here is the almighty $$$$. Depending on what you want to spend,you have alot of options. Any discount performance parts places(Jeg's, Summit, etc) all have small body distributers. It is a SBC not exactly a hard one to find parts for. If you want reliability, you can't beat an OEM HEI-most people I know carry an extra module i the glovebox anyway. Just my 2 cents worth. Personally, I use nothing but MSD, not cheap, but they work and last.

[tincan1966]

Don't forget, when switching to HEI, the resistance wire from the bulkhead connector to the distributor need to be completely replaced with non-resistor wire. Have seen alot of people try to "cut it close to the connector and splice in the new wire" This does not work, the HEI needs and likes a full 12V to operate and make the module last. Also make sure you have a good engine to frame ground strap(the motor mounts do not count).
I am not sure I would mess with a salvage yard unit unless you are going to refurbish it. Hate to see you get it installed and have a no-start and no idea what went wrong. Decent rebuilt units are available and most parts stores and not bad priced and most with a lifetime warranty, module and pickup coil included.

[tomfg]

I didn't realize that you could purchase complete, OEM HEI, rebuilt distributors. Thanks, I'll check that out. Looks like most EBay OEM used ones are going for $40 to $80 with shipping, and you'd still need to replace modules, caps, etc.

[HEI451]

Yes, you would, those on E-Bay are generically the same as the ones manufactured by the less than reputable people I mentioned before.

Also, as I said before, no real need to carry a spare module, module failure is caused 99.99 percent from the coil going bad, so, a spare module won't be of much help when the coil goes, it'll take that spare module out too.

One company, Wells, an aftermarket manufacturer, supplies a lot of HEI parts to GM, so, use that info any way you wish, but it is good stuff, same as NAPA, Borg-Warner, Neihoff, Sorenson. PLEASE, don't waste your money on specialty modules like the MSD, they just plain don't give you the added performance, nor added reliability over a stock type module, vs cost.

[tincan1966]

I guess I am failing to see the complexity of this conversion. I personally would buy a new part than mess with a used one for something as inexpensive as a distributor. Autozone has rebuilts done by AC delco. Sorry I offer help thought it would be simpler. Good luck.
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[tincan1966]

MSD fires our nitro fuel altered for 3yrs no problem. I believe the reliability is there. Comes down to what you are willing to pay for vs the use. A stock unit would never run our race car but that unit would be overkill on the street. Apparently I am completely wrong on this topic.
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[tincan1966]

I need to apologize for how my previous posts sounded, kinda hard to type in how the message was MEANT to sound.LOL!
Again I apologize to the OP and others who posted if I was offensive or disrespectful, was not my intention to come across that way. I was merely using 25+ yrs of experience to offer a little advise/opinion.

[jimmydean]

I got a stock style HEI that was used once (ran for about 10 minutes) to dyno a new motor with wires off ebay for $40. Haven't got it all in yet, but it was cheap and perfect for my rig.

Yes, the MSD and other setups are nice, but unless you are building a performance engine, a stock HEI is a great upgrade.

[HEI451]

I ran a pinch head Chevy engine in my AA/FA for years, off a less than optimal Vertex mag, no issues. There weren't any MSD magnetos back then, only Mallory and Vertex.

In my opinion, and, experience, MSD is the best you can get, except for their over the counter large cap HEI, NO difference from a well done stocker, the Street Fire series of items, and, their Mexico and China made Blaster and HV coils. The rest of MSD's lines are simply TOP NOTCH in the industry.

Now, I KNOW that a large cap HEI, nor a Street-Fire system are never used in a fuel altered, just isn't done, so, the MSD MAGNETO used in them is a LOT different than those other systems, and works excellent.

There is a giant difference between an MSD magneto, and their lowest line of products I mentioned.

[tincan1966]

Well again I suppose us "Middle Coast" guys don't know much, other than the outstanding quality of the MSD HEI I run in my daily driver isn't even close to any "stocker"(ie sealed brgs in MSD opposed to bronze bushings in an OEM, machined billet body opposed to an "ass,oops as-cast"
I know I will be wrong no matter what point or opinion I post, so will leave this thread to the "experts".

[Captainfab]

I don't see anything wrong with your posts....and no need to appologize. Your input is welcome

Originally Posted by tincan1966

I need to apologize for how my previous posts sounded, kinda hard to type in how the message was MEANT to sound.LOL!
Again I apologize to the OP and others who posted if I was offensive or disrespectful, was not my intention to come across that way. I was merely using 25+ yrs of experience to offer a little advise/opinion.

[redneck6]

what module are yall refering to that goes with a pre 87 esc controlled hei dis ? or am i missing something ? i thought all was need for a pre esc distr is a 12 gauge or bigger keyed hot wire for the coil ?

[HEI451]

Oh, get off being a martyr, will you. I have 42 YEARS of experience in all sorts of automotive and motorcycle fields, including being one of the people that worked at GM to develop the HEI. That said, a ball bearing ISN'T the right thing to put in an upper bushing area, they wear, and get loose, where a roller or solid bushing wears significantly less. That info ISN'T brain surgery, nor rocket science, ask any good bearing parts person, they see ball bearing wear out EVERY day, and can advise you to use a roller, or bushing in place of the ball, EVERY time.

BTW, pull one of those "seals" OUT of the ball bearing, the lower seal, that will get engine oil vapor to lubricate that upper ball bearing, instead of the sealed bearing wearing out prematurely from the grease running away from the roll/contact area of the ball/race, and down against that lower seal you should pull out of that bearing, PROVEN FACT. And,m if there is a lower ball bearing, it should be completely open, NO SEALS at all, so the engine oil can migrate to the balls/race, also PROVEN FACT. Better yet, put ONE seal in the top of the housing, and replace the ball bearings with rollers, or bushings, and stop the mayhem of the ball bearing wear.

But, then, YOU are the expert on YOUR particular MSD distributor, according to YOU.

I said MSD was the best their is, and I stand with it, so did you, and you stand with it, no problems there. NOT ALL MSD PRODUCTS ARE THE BEST, MOST ARE JUST PLAIN TOP NOTCH, SOME SMALL FEW HAVE SERIOUS ISSUES.

As far as other things discussed above, the feed wire only needs to be giant when the in cap epoxy coil is used, as they get hot, which is electronic resistance, load and that requires bit amperage to keep the output even to a minimum. Move the coil out of the cap, use an oil filled coil, and you only need a 14 gauge wire to feed the HEI, this is PROVEN FACT with a small body HEI with remote oil filled coil.

As far as modules go, there are a number of them, for different types of applications.

First is a 45 pin module, for analog systems, those with vacuum and mechanical advance, as we would use in our carburetted engines.

The next is virtually the same, but with 5 pins, to accept a retard signal from a stand alone knpock sensor, mostly used on some Cadillac, Olds engines

Then, there is a 7 pin module, which was used as a feedback system tool, info to the computer, then back to the module, for Electronic Spark Control. These systems did not use a vacuum nor mechanical advance, and have two wire looms out of the distributor. These modules were also used for the earliest Electronic Fuel Injection Systems

The latest module has 8 pins, and works much like the 7 pin ones, but, has a dedicated ground wire the 7 pin doesn't have, to ensure the module is grounded. Earlier 7 pin modules grounded their feedback systems through the bottom plate, the 8 pin through its own dedicated ground wire