silverriff

I have a pretty stock 455 transplanted into my 1972 Cutlass. Im cleaning and tweaking, trying to get it into better, reliable performance ( gas is hitting $4.50 for 91 oct. here in Maryland). I have the original distributor in there, and was thinking of upgrading to HEI. I read a few threads that mentioned the electronic ignition upgrade from Petronix to keep the stock distributor, but my questions is this.... if I am not concerned about being 100% stock (which the car is far from to begin with) is HEI a better all around choice? Also does price/namebrand mean better performance/quality? Base HEI's from places like Mallory and Accel run upwards of a few hundred bucks to $400.00. But I have seen some off-brand HEI's on Ebay for as little as $36.00, for the complete package. Anyones input would be much appriciated.

joe_padavano

First, used factory HEIs can be had for $15 or less. You can get an Accel cap and rotor kit for $28 or pay less for white box parts. Do not get any HEI that doesn't have a vacuum advance canister. These are the computer-controlled distributors from the 307 and won't work without the computer.

As for points vs. electronic, I'll be the first to say that when the points are brand new, the two systems are equivalent. The difference is that points start to deteriorate immediately while electronic doesn't.

Olds64

If you are going for reliability and easy maintenance then buy an HEI distributor. You never have to set dwell or point gap on an HEI distributor.

Redog

have to say HEI, althought I'm having trouble with mine.

Don't go running out and spending $300 to $400 for a "Hi-performance" HEI like MSD or Mallory. They really only start to benifit you if the car's running low 10's in the 1/4 mile and even then, it's very little.

I will however say that I like the rev limiter feature on the Mallory 75 dis, but it's not worth the $415 IMO

J-(Chicago)

Rev limiter?
Redog you should be able to beat on that 350 at 6500 rpms every weekend.

88 coupe

Yes. Factory GM (or equivalent) ignition systems will handle a lot more power than most street engines will ever make.

I put my 3950 lb Grey Coupe into the elevens, using Delco points, wires, and coil, but that was before I learned (on the internet) that it was not possible.

Performance? No.

Quality? "OEM equivalent" is all you need to know.

Ebay = Caveat Emptor = Let the buyer beware.

Norm

88 coupe

Good thing to have if one does not have, or cannot read, a tachometer.

Norm

Redog

6500 with an Olds 350? I thought the redline was 5500.

I reved it past 5200 once I use 5200 as my redline

redoldsman

Joe gave you good advice. I have had my 72 Cutlass with a 350 for 15 years. An HEI was the first thing I did after I put dual turbos on it. I bought a junkyard distributor for about 35 bucks and use a good cap with brass contacts and a good set of wires. It starts quicker and you get a lot bettet plug life. Although the mileage may be a little better it will probably not be enough to notice. If you want a little more, you might put a high voltage coil on. In my oninion this is one of best improvements you can make for the $$ you spend. Gap you plugs at 45-60 (there are a lot of opinions on this) and you should be good to go.

Gaz Hog

I had an all stock Delta 88 with a 455. I put a new Intake on it, 4bbl and HEI! I used to have to fill'er up with premium, now, with the HEI I don't have any problems with 87 octane. I like the all original look, it's nice not having to deal with the points and condenser all the time. And it's also nice not paying $4.30 per gallon. I don't recall how much a paid, but it wasn't very much. A friend of mine had the cap and coil he gave me. You should be able to find some good stuff at salvage yards. Oh, and I get 15 1/2 miles per gallon out of it. A little better than before.

Gert3116

I put a summit racing distributor on my cutlass . I bought it for like $180 and I've never had a problem with it.

Rallye469

2X
My engine was dyno'd with and without an MSD system. It really didn't make much of a difference. 4hp @ 6200 rpms
We did notice some some fluctuations down low and the msd system
appeared a bit smoother.
As far as real world...I'll tell you the difference the second I get to the track.

joe_padavano

That is not directly related to the HEI swap as much as the difference in the advance curves in the two distributors. You could just as easily have changed the mechanical and vac advance curves in your points distributor and run the car on regular gas also.

Olds64

You can easily tell the difference between an HEI and points distributor by hooking up your engine to a spark analyzer. However, most people don't have these expensive tools lying around. Actually, I doubt many shops have them anymore.

88 coupe

What is a "spark analyzer" and how does it tell the difference between two different distributors?

Assuming it could, how would it determine which would work "better" in a given application?

Norm

joe_padavano

I'm assuming (yes, I know...) he meant an oscilloscope, and suspect you'd see a different pulse from the higher voltage HEI than a point-style distributor.

88 coupe

A "scope", as normally used in a shop (and in the context of this discussion) will only show the actual voltage used. If a "load" is applied and more voltage is required, the coil output will be increased, as needed.

A slightly different pattern is possible, but the peak voltage will remain the same. Coil output reflects the needs of the engine, not what is available.

The triggering method, has little (if anything) to do with the the output of the coil.

If a given coil is capable of producing 1,000,000,000 volts, but only 10 volts are needed to fire the plug: How much more than 10 volts, will that coil actually make. What will a "scope" show?

But more importantly: What will Olds64's "spark analyzer" show?

Norm

joe_padavano

I'm going to have to disagree there. Faraday's law says that the output voltage is a function of the number of windings and the rate of change of the magnetic field in the primary side. There's nothing on the "demand" side of the ignition system that can change the output voltage. A coil from an HEI will have a higher output voltage than a normal point ignition coil, due to the number of turns on the secondary side of the coil.

Agreed, to the first order. In reality, the rate at which the magnetic field on the primary side changes does have an effect on the secondary side output voltage. An electronic trigger can be tailored based on RPM. Points cannot.

Oldsguy

Norm, you won't get a response from Olds64, he doesn't see your posts. I will verify that he was referring to an Oscilloscope. During his college years, while taking one of the earlier classes he related to me what he was learning, and in fact showed me during one of my visits. It was referred to as a spark analyzer by the instructor because that was how it was being used, as a tool to look at the spark patterns. There actually is a difference in spark patterns even if they posses the same peak value, the shape of the pulse can be steeper, or more shallow. This is what he was shown and related to me. I do not remember what shape the HEI pulse would be, or if a particular shaped pulse is more desire-able. I do know that looking at all the pulses and comparing them may be a useful diagnostic tool. Me, I just change the plugs, wires, rotor, points, and cap on a regular basis.

88 coupe

Yes, it does.

The "demand" comes from the combustion chamber, not from the ignition system.

Nothing to do with anything. Both are capable of producing far more voltage than the engine will ever need.

Let's put it back into perspective, shall we?

In this example, a "scope" would show 10 volts. What would "Faraday's law" show?

Only if a timing device is used with the switch. Not done with the HEI (or the Pertronix, Mallory, and Accel, the OP asked about) as it used a centrifugal/vacuum advance system.

No simple switch, mechanical or electronic, can.

Norm

88 coupe

I did not expect one.

And we all know why, don't we.

Thanks for the clarification.

Due to my limited education, I have been forced to "make do" with a year (or two) of "hands on" experience.

No argument here. There are always differences from engine to engine, and from cylinder to cylinder.

The "peak" shows the actual voltage, at that plug, on that unique event.

If the circuit is grounded, the "peak" will only show the voltage needed to overcome the resistance (through the cap, rotor, wires, etc.) between the coil and the actual ground.

If the circuit is open, the "peak" will show the voltage the coil is capable of producing.

Yes, very useful. How much, depends on the experience of the reader.

Norm