Changing points to HEI
#1
Changing points to HEI
I am thinking of changing my points ignition over to HEI possibly using Pertronix on my 71 Olds 350 engine. First, how hard is it to change over and second...I've heard a few different views on
Do I need to change plug wires?
Do I need a new coil?
Do I need a new alternator with HEI?
Do I need to change some lead wires to compensate for 12 volt HEI?
What plugs and gap are best?
Thanks...Billy
Do I need to change plug wires?
Do I need a new coil?
Do I need a new alternator with HEI?
Do I need to change some lead wires to compensate for 12 volt HEI?
What plugs and gap are best?
Thanks...Billy
#2
First off, HEI and Pertronix are NOT the same thing. Pertronix is simply an electronic version of points (electronic switch instead of mechanical switch).
The difficulty depends upon which system you are going to use. I have no hands-on experience with Pertronix systems, but from what I recall reading it involves replacing the points with the electronic module and (perhaps?) running a full 12 Volt wire in place of the existing resistor wire.
Do I need to change plug wires?
HEI - yes as the distributor cap utilizes a different style plug wire end.
Pertronix - no, the original cap and plug wires are retained.
Do I need a new coil?
HEI - yes, the coil is in the distributor cap.
Pertronix - uses the original coil.
Do I need a new alternator with HEI?
No.
Do I need to change some lead wires to compensate for 12 volt HEI?
Yes.
What plugs and gap are best?
There are many opinions on plug brand.
For HEI, the plug gap can be opened some to take advantage of the higher output. I use .045" on my car.
For Pertronix, I don't think there is any change in voltage, so no change in plug gap.
The difficulty depends upon which system you are going to use. I have no hands-on experience with Pertronix systems, but from what I recall reading it involves replacing the points with the electronic module and (perhaps?) running a full 12 Volt wire in place of the existing resistor wire.
Do I need to change plug wires?
HEI - yes as the distributor cap utilizes a different style plug wire end.
Pertronix - no, the original cap and plug wires are retained.
Do I need a new coil?
HEI - yes, the coil is in the distributor cap.
Pertronix - uses the original coil.
Do I need a new alternator with HEI?
No.
Do I need to change some lead wires to compensate for 12 volt HEI?
Yes.
What plugs and gap are best?
There are many opinions on plug brand.
For HEI, the plug gap can be opened some to take advantage of the higher output. I use .045" on my car.
For Pertronix, I don't think there is any change in voltage, so no change in plug gap.
#3
Ken pretty much covered it... I'll add that there is nothing wrong with the simplicity of points and the only gain with a pertronix is you don't have to take 15 mins a year to reset dwell/timing or change points.
#4
And the Pertronix won't float like cheap points can at higher RPM.
#6
yes, you would be smart to replace the alternator at the same time, or before, an HEI upgrade. the points switching of the externally regulated alternator can cause misfiring of the HEI system. that is the precise reason that gm changed to the internally regulated alternator when HEI was rolled out.
the reason you replace the plug wires is due to the higher voltages/current in an HEI system, and the different cap tower style. you use the exact same plugs as before-the plugs don't care about the ignition system. i run a .045 gap also, it works well.
the existing coil + wire can be used to drive the relay you'll need to install to switch the higher current draw of the HEI system. fuse the HEI B+ feed at 20 amps, and make the B+ wiring for the HEI power at least 12 gauge, 10 gauge is better, no reason to run anything larger than 10 gauge. pick an HEI distributor that has a mechanical and vacuum advance curve as close as possible to your current curves, or have an HEI distributor recurved to match your current curves. after you get it in and working you can play with advance curves to squeeze a little more power out of your motor.
bill
the reason you replace the plug wires is due to the higher voltages/current in an HEI system, and the different cap tower style. you use the exact same plugs as before-the plugs don't care about the ignition system. i run a .045 gap also, it works well.
the existing coil + wire can be used to drive the relay you'll need to install to switch the higher current draw of the HEI system. fuse the HEI B+ feed at 20 amps, and make the B+ wiring for the HEI power at least 12 gauge, 10 gauge is better, no reason to run anything larger than 10 gauge. pick an HEI distributor that has a mechanical and vacuum advance curve as close as possible to your current curves, or have an HEI distributor recurved to match your current curves. after you get it in and working you can play with advance curves to squeeze a little more power out of your motor.
bill
#7
But he's not getting an HEI, he's getting a Pertronix.
An HEI coil in cap draws only 2 to 3 amps, compared to the 6 amps an external oil-filled coil, I have never heard of a serviceable mechanical voltage regulator causing issues with an HEI.
An HEI coil in cap draws only 2 to 3 amps, compared to the 6 amps an external oil-filled coil, I have never heard of a serviceable mechanical voltage regulator causing issues with an HEI.
#8
Changing from points ignition
So.....if I wanted to go to a Pertronix system on a 71 350 engine and get away from points but not go into full HEI.....anyone have experience with this?
What has to be done to convert AND...how hard is it?
Thanks for some of your previous answers.
What has to be done to convert AND...how hard is it?
Thanks for some of your previous answers.
#9
I have a Pertronix in my 54 and have had one in my boat for years. It is a very simple installation. I also changed to their high output coil. You are not going to get any more power but you will get quicker starting and no maintenance. Some guys on here love points and that is okay. Pertronix conversions and electric fuel pumps are always debatable issues on here and I like them both. I run about gap my plugs at 40.
#10
If you have any wiring and tune up skills at all, it is extremely easy. The Pertronix comes with instructions. READ THEM FIRST.
You may find that it makes a lot of sense to get a new coil, cap, rotor, and wires at the same time, as old parts will negate the benefits of any electronic ignition installation. Also, don't expect any magic HP benefits. An electronic ignition conversion like this will provide exactly no benefit over points that are in good shape at normal engine speeds. Yes, if you regularly run your engine over 5,000 RPM, the electronic will provide a more reliable spark, but how many Olds motors do that regularly? Damn few, if we'd all be honest with ourselves.
I've converted many of my cars to electronic for laziness reasons, not performance ones.
#11
That 15 minutes a year adds up. I did the switch two years ago, so I'm a half-hour ahead already!
#13
I would check them. Dwell can be well out of spec and timing can be well out of spec, and the car will still appear to run fine. But it's amazing how much better it will run if these are in proper adjustment.
#14
Points arc over time, which both increases resistance (lowering spark current) and alters dwell (and possibly timing). Gradual degradation is hard to sense if you don't have a reference point. I suspect that back-to-back comparison testing with new points will surprise you.
#15
#16
#17
#23
how did you come up with those HEI current figures? you understand that the module has the ability to control coil current and dwell time, right? vehicle running? what rpm? do you understand about inrush current? do you understand voltage transients and how they can cause an HEI to misfire??
ok, so you never heard of it, GM figured it out a long time ago. besides, solid state regulation is far superior to electro-mechanical regulation.
bill
#24
have you folks running points lubed your rubbing block lately?
points are going to arc, it's their nature(the condenser is an attempt to decrease that). this arcing causes pitting and erosion of the contact surfaces. points also oxidize over time. the piece that rides on the dist. rubbing block also wears(less, with proper lube). have you checked your breaker arm spring tension lately?
bill
bill
points are going to arc, it's their nature(the condenser is an attempt to decrease that). this arcing causes pitting and erosion of the contact surfaces. points also oxidize over time. the piece that rides on the dist. rubbing block also wears(less, with proper lube). have you checked your breaker arm spring tension lately?
bill
bill
#25
how did you come up with those HEI current figures? you understand that the module has the ability to control coil current and dwell time, right? vehicle running? what rpm? do you understand about inrush current? do you understand voltage transients and how they can cause an HEI to misfire??
ok, so you never heard of it, GM figured it out a long time ago. besides, solid state regulation is far superior to electro-mechanical regulation.
bill
ok, so you never heard of it, GM figured it out a long time ago. besides, solid state regulation is far superior to electro-mechanical regulation.
bill
#26
you have no idea of my background either, this aint a pissing match. you never answered my questions. i never said that a points-regulated alternator would damage an HEI system. it can cause misfiring of it though.
bill
bill
#27
so, for those of you that want to understand more about how the HEI system works, this is a good read: http://cyberdave.org/HEICoilInfo.html
and for the really technically-minded: http://datasheet4u.com/datasheet-pdf....php?id=504561
bill
and for the really technically-minded: http://datasheet4u.com/datasheet-pdf....php?id=504561
bill
#28
I swapped out my point dist. for HEI at the same time I converted from an externally regulated alt. to an internally regulated alt.
I went to the junk yard and grabbed an HEI from a 77 Buick with an Olds 307 $45. I modified the wiring harness on my car by removing the resistance wire going to the old external mounted coil and replaced it with a 10 gauge power wire for the HEI;
I gapped existing plugs to .045";
Had to modify the spark plug wires since the ends are diff for HEI on the dist. end - not the spark plug end. Could have bought new wires but was able to make some that worked with stuff laying around.
The car runs better with the HEI and firewall is cleaner since there is not a separate coil to mount. The coil for the HEI is in the cap.
I went to the junk yard and grabbed an HEI from a 77 Buick with an Olds 307 $45. I modified the wiring harness on my car by removing the resistance wire going to the old external mounted coil and replaced it with a 10 gauge power wire for the HEI;
I gapped existing plugs to .045";
Had to modify the spark plug wires since the ends are diff for HEI on the dist. end - not the spark plug end. Could have bought new wires but was able to make some that worked with stuff laying around.
The car runs better with the HEI and firewall is cleaner since there is not a separate coil to mount. The coil for the HEI is in the cap.
Last edited by VinMichael; September 7th, 2015 at 11:07 AM.
#29
Yes, and that coil in cap is not really a good thing. The coil generates heat, and being epoxy encapsulated it doesn't dissipate the heat well, then it heats the ignition module, and electronics don't work optimally at elevated temperatures. A high performance setup is the HEI distributor with a good quality external oil filled coil.
With that said, I have not noticed any issues with my coil-in-cap HEI in the past 30 years.
With that said, I have not noticed any issues with my coil-in-cap HEI in the past 30 years.
Last edited by Fun71; September 7th, 2015 at 10:41 PM.
#30
I have used Pertronix in several old cars over a 20 year period, with no problems. As mentioned previously, you will not gain any horsepower, but you engine will run like it is on brand new points all day, everyday. I would buy the Pertronix Ignitor I. You don't need hotter spark or a rev limiter on a stock or moderately modified engine. The only difficult thing is getting 2 wires to fit through the rubber grommet in the bottom of the distributor. You could pop out the grommet and not use it, but maybe the wires would wear over time and fail. If you pull the distributor, enlarging the grommet for 2 wires is simple.
#31
the coil heat doesn't transfer to the module, the module is mounted to the distributor body. the engine heat transfers to the module, however, it's all automotive grade stuff, so the heat factor is not a problem. also, the module controls the dwell and limits the current to 5.5 amps to help keep the coil cooler. HEI also produces a spark with longer duration vs. the stock points system, this helps to ensure the mixture ignites and burns more reliably.
bill
bill
#32
NOW I have another question for any Pertronix users....do you have to remove the distributor to install the Pertronix Ignitor I or II system??? I have heard it both ways. Then would you still change the coil also?
Thanks!
Thanks!
#33
You do not have to remove the distributor. Be careful not to lose any of the small screws though. I have installed several and never pulled the distributor. I have always changed the coil and widened the plug gap to about 45 thousandths.
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