1967442

"HEI ignition vs points vs CD Ignition" How do each of them compare? I am planning to convert on of my 442's (I only have two) to UHV-CD ignition. I plan on making this car a driver. My concerns are durability, reliability and performance. This car is mostly original ( motor, interior and trans are original to the car ) I have never driven a car with the K-66 setup. I want to experience it for myself.

Loaded68W34

FYI, it may have been better to start a new thread than to resurrect one from 2014. That said, I run points on most of my classic cars, but my Toronado is a factory K66 car. I am also running a 6AL and MSD pro-billet distributor on my Chevelle (MSD box hidden inside fender and running a black points style cap to make the distributor look somewhat original) From a drivability standpoint, I can't say I notice a huge difference between the three. I really only went to the MSD set-up for the rev-limiter. One thing about the K66 ignition is that the timing is crucial. When I first finished my Toro, it had an idle surge while cruising that I could not figure out. I happened to come across an original service bulletin from 67 or 68 stating that the timing had to be set to a specific number or surging would occur. I believe it was 12 degrees and I had the timing set to 14. Reset according to the bulletin and the problem was gone. I can't find the site that had the bulletin, but I printed it out to keep in the record binder I have in the car. I would have to dig it out to be sure about the exact timing listed.

oldcutlass

I moved your post to it's own thread instead of resurrecting an old one. Points are about as simple and reliable you will get for an ignition system but do require periodic maintenance and can rev over 6k RPM with a good set. An HEI is a great alternative if you don't want to mess with changing points, but no real performance gain. I am not familiar enough with the K66 ignition system to comment. Ignition systems alone do not relate to massive increases in performance.

Koda

UHV and HEI are the same thing, it's just that the guts are on the coil and integrated cap for HEI, whereas UHV had a coil in the normal spot and a separate guts box. Those are pointless.

CD was an addon to a normal distributor which did half of the stuff HEI did. There was an article around here somewhat recently.

Points are fine for normal driving, require some upkeep. On the other hand, I haven't touched the points in 22 years and that many thousand miles on my Chevy. Points fail gracefully, electronics chips fail forcefully.

1967442

Thanks for the head up and moving my post to the correct spot. I am and "old" newbe.

67OAI

UHV and HEI are really not the same thing: Joe P. has a great paragraph describing the differences somewhere in the forums. Biggest take I got from his info is that the UHV being a CD ignition has a very short duration spark whereas the HEI is a longer duration spark and not CD (capacitive discharge). My '67 had K66 from the factory and was a great ignition in its day. If I were to replace it today, I would use either the HEI or the MSD 6 series. I think there is someone out there that rebuilds the UHV amplifiers with updated electronic components for better reliability as I heard somewhere they got a bad rep for failures; as an aside, mine never failed while I had it on the car for two years.

BangScreech4-4-2

As noted above, points are simple and reliable. If old or worn, they will usually fail slowly and the engine can usually be made to run well enough to get you home. HEI is time tested and reliable, but a bad module can happen suddenly and leave you stranded. Many people carry a spare. I had an MSD CD unit in a small block Camaro. No complaints. There is little, if anything, to choose between them in terms of performance.

Finally, I would not use a K66 except in a concours restoration that would see limited street miles. The setup is rare and limited production, and being an early iteration of electronic ignition, I would question its long term reliability in a driver-type car. Save it for the big-dollar guys.

Oldsguy

Amen to that Bro.

Loaded68W34

To compliment this, my Toronado still has the original K66 system on it (amp, coil, distributor, and wiring harness). Over 80,000 miles and 55 years later it still works great despite sitting unused from 1986 to 2017. The only things I replaced on the ignition system were the cap, plug wires, and spark plugs. The original cap and plug wires were replaced in the late 70's, so I got a correct red NOS K66 cap and reproduction dated spark plug wires.

Koda

I meant to say the circuitry was, as in you can use an HEI circuit board in a UHV case.

83hurstguy

Sometimes. My friend grenaded the inside of his mufflers because the points came apart halfway down the dragstrip, leading to a fuel buildup and huge kaboom in the exhaust...

Regarding the K66/UHV, if you're going to do any long distance driving, I'd put an HEI module in an original box and call it good. Easy to carry a spare module.

matt69olds

Ignition points are about as simple as you can get, but they do require maintenance. I believe in the tune up section of the service manual it says to clean or replace, set the dwell, and reset the timing every 10K miles. Since these cars are rarely used as daily drivers, 10k miles is a lot of summer cruising.

HEI is also very simple, and very reliable. The HEI module did have some reliability issues early, but it didn’t take long for Delco to solve the problem. However, the myth lingers. I have had 2 module failures in my almost 40 year driving career. One failed only when hot, the other was a complete failure. Other than the module, the only other big failure item is the tiny wires for the pickup coil.

The MSD ignition in my experience is also very reliable. The 6AL box on my car has been there almost 30 years. The addition of a rev limiter is a nice feature. MSD stands for Multiple Spark Discharge, below 3k rpm the box delivers several sparks per ignition cycle. Above 3k, it’s one long spark.

I have zero personal experience with the K66 ignition.

cfair

I’ve got 2 street-use Olds big cars and have converted both to HEI. I’m one of those who doesn’t like to mess with points.

I carry spare modules in each car since I’ve had a failure or 3 (but not more in 40 years…). With HEI you can swap the module out on the side of the road if you carry the right hand tools. But yes, HEI modules fail inelegantly.

If you go HEI, look into progression ignitions Bluetooth HEI distributors, they figured out how to replace vacuum pots and springs with a Bluetooth controlled timing map that lets you have no advance when cranking (easer on the starter), more at idle (smoother idle), less midrange and WOT advance per your liking (meaning you can avoid knock/ping). I’ve just put these in my cars in the past year and cannot comment on longevity but I’m very happy with them so far. As a bonus, you can disable the car’s distributor from your phone to reduce chances of car theft.

If you’re showing the car & into correctness and the actual 60’s experience, go for the now rare & exotic Olds CD system. If you’re using the car a lot for around town or road trips, I’d aim at either points or HEI since you’ll be able to find replacement parts and know how many many more places you might take the car.

Cheers
Chris