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Points or other ignition

7K views 31 replies 11 participants last post by  BearGFR 
#1 ·
I have purchased a 65 GTO. It has a 70 455 with the 66 Tri Power set up. The car has the factory points Ignition in it. The guy that owned the car before me said he never had any performance issues with the engine with the points. I thought about putting an HEI Distributor in the motor, but it wont clear the rear Carburetor. Considering that I will not be racing the car and it will only be my good weather weekend driver, I think the points distributor will probably be fine. Anyone have any thoughts or advise on a replacement distributor. Thanks :)
 
#4 ·
I've run nothing but stock points and condenser ignitions in all of my GTO's over the pat 33 years. 100's of thousands of miles of driving, with no issues. No reason to "upgrade". Just stay away from the "uniset" (combined points and condenser) and be sure to replace them every 15,000 miles or so when you do your tune up. I have seen and I have heard of a lot of reliability issues with "upgraded" ignition systems....and these are issues that leave you stranded. The advantage of HEI is "no maintenance" I've seen more than my share of bad modules and magnetic pickup coils in other people's vehicle's. For a street driven, real world car, original is hard to bead.
 
#7 ·
I like the HEI myself as an upgrade, as you can get parts at any store for it. Boats still like points as you can just sand the points, regap and get it running again. Your stock dist is 46 years old, so at least make sure the shaft is tight and advance weights work correctly. I would upgrade to the Pertronixs for the hotter spark and wider gap, incresed performance. Back in Highschool I used Sorensen cross cut points and threw the lightest advance springs in and it was a tire shreader, 66 tempest 455.
 
#8 ·
I hate points, the only thing I hate more than points is dual points... maybe I am jaded because I could never afford new points for my motorcycles as a child. Always with the Emory cloth or Bristol paper. I am all about solid state, to me it can't be beat. Waterproof and always the perfect timing. I would pay 75 bucks any day of the week to spare myself the headache :) just my 2 cents.
 
#9 · (Edited)
I hate points, the only thing I hate more than points is dual points...just my 2 cents.
Pretty much the same as carb compared to fuel injection.. Carbs are cheaper, with injection you never have to adjust fuel ratio because the humidity changed or changed elevation. And the benefit of good fuel mileage. One perk, carb improvements are cheaper than injection, that's why I came back to old school.
 
#10 ·
I went with a Pertronix Ignitor III in place of the points. It has a built in rev limiter. I'm very happy with that setup.... They claim, "ignition box performance w/o the box"...
 
#11 ·
A few years ago, I did actual dyno testing at Westech Performance with Hot Rod Magazine on stock points versus MSD and Crane HyFire ignition systems. Matt King with Hot Rod and Steve Brule with Westech were with me. We ran a 302 Ford street engine in the 370-horse range with an MSD distributor, set up and curved on the Westech distributor machine. We ran it with the MSD module, and then ran it with the HyFire module. Then, I went out to the parking lot and yanked the stock distributor out of Matt King's piece of crap 302 Falcon. He ran over to NAPA and bought a new set of points, and I set the thing up on the distributor machine to match the same curve that the MSD had. We swapped out the distributor, eliminated the HyFire system, and did 4 more dyno pulls with the same total timing as the MSD/HyFire.

Results: Absolutely no differenece whatsoever in the torque and power curve. None. Not even 1 horsepower anywhere on the usable rpm range (up through 5800).

If your stock points-style distributor is properly set up with a good set of points (I run the NAPA/Echlin CS786 in all my GM distributor builds - they will run through 6100 rpm with no bounce), you won't gain any more power or reliability going to any "fancy" aftermarket magnetic or optical trigger systems. The CS786 points will hold their dwell through their 20,000-mile life, which is longer than most people ever own these cars.

If you need assistance with the setup, I can rebuild and set up your distributor (with points) with a very nice performance curve on my Sun machine.

Lars
V8FastCars@msn.com
 
#12 ·
Lars, you're my hero!! Thank you for once again providing factual information that backs up what you, I, Bear, and others have realized over the years: Factory stuff actually works very well. Once the mixture is ignited, it's ignited. It doesn't matter by what source.
Jeff
 
#13 ·
I thought I was just being cheap. I looked at pertronix for a long time, but decided to stay with the points. Having a tight budget, I have to scrutinize every purchase. Its nice to know so many others are happy with them too. They're just a little more work to maintain, but thats ok.
 
#14 ·
This is me (on right) and Matt King, Hot Rod Editor (left), in theWestech dyno cell setting the dwell on his Falcon distributor to run it against the magnetic CD ignition systems. Engine for the testing was a 302 Ford. Proving that a stock, recurved points distributor can match the performance of the aftermarket systems does not make for good press in a magazine supported by the aftermarket vendors, so the results of this testing never made print in Hot Rod... we also used the engine for another article which did make print:


Lars
 
#15 ·
I knew I joined this Forum for all the right reasons. I really appreciate all the good opinions and the factual information provided by lars and geeteeohguy. I have submitted numerous questions to the Forum and have great responses on all of them.
timmyg
 
#16 ·
Lars, so quality points are good to 6100 when new, lesser points fall off sooner. What does spark gap do for performance and higher voltage? Also, did you tighten the spark gap going to the points? OK, so an MSD doesn't add horse power, but the dual/tripple discharge in the lower RPM's should ensure full fuel burn, while a single weak spark wont' do a complete burn?? I have a Taylor Mileage master out of a van, pretty heavy duty unit that has to improve mileage.. SO what is the black magic if you say it doesn't make a difference.
I service fleet vehicles, and my boss told me that as long as an oil is API certified to your requirement then it's good. Oil is a Billions of dollars a year industry, and they spend tons to make you believe awesome oil is better. Synthetics do last longer, but with religious oil changes, conventional is fine. Our cars do take ZDDP, but that's another story. Diesel oil is stronger and is great in the old cars, but bad with Cats. So, I'm assuming the same thing with the points.. I also realize low tension rings makes engines last longer, a point synthetic oils take credit for, but I have a 200K 4.3 that I put heads on that had minimal cylinder wear and lived it's life on conventional oil.
 
#21 ·
The whole dual/tripple discharge spark thing is bogus. Once the mixture is ignited, that's it. A standard, factory spec ingnition system that is maintained does not produce a weak spark. All that MSD snake oil stuff is just Feel Good electronics, IMO. Never used it, never will, no need to.
 
#22 ·
OK, so a few more of my opinions:

For a mild street vehicle, or a stock engine, a well-tuned and properly curved stock-based distributor and trigger system works just great, as I've noted earlier based on factual testing and real dyno numbers. The Royal Bobcat SD 421 cars were setting NHRA records with stock distributors and points, and we were running points in our 455SD SS/KA cars in the mid-70's. No problem going fast...

Obviously, the makers of the aftermarket systems need a niche for selling their products. Most stock distributor systems are set up pretty lousy, since few people have access to a distributor machine, nor do most people understand what a "good" timing curve should look like or what constitutes a good set of points. So Mallory, MSD, Accel, Proform, and Pertronix can make a distributor with a mild performance advance curve in it and sell it as a "performance" part. When you bolt in the new distributor with the improved timing curve and fancy CD trigger box, you get an instant performance increase. Isn't that amazing.

In an actual racing engine, there are 2 things that put your ignition system at the limits of its capability: Dynamic cylinder pressure and rpm: A high compression racing engine can operate at very close to 100% volumetric efficiency at its torque and power peaks, which means that the cylinder pressure just prior to the ignition point is extremely high. As pressure goes up in the combustion chamber, the resistance across the plug gap goes up, so higher voltage is required to jump the gap. For this reason, racing engines, even with high voltage CD systems, will limit plug gaps to .035 - .045. This assures that the resistance across the gap, under high dynamic cylinder pressure, does not go up so high that the high energy ignition system does not arc across a point with less resistance, such as inside the cap, or off a plug boot. It is possible, in high performance engines, to get the cylinder pressure, and resulting plug gap resistance, so high that a "normal" stock ignition system will not fire the plug. Thus, a high energy aftermarket system would be required. I have never seen this happen in a street-drivable vehicle. Likewise, an engine operating at very high rpm offers very little time for the coil to saturate and produce the required high voltage discharge. Magnetic trigger systems, capacitive discharge, and aftermarket coils offer quicker rise rates, more effective dwell duration, and higher secondary voltage to assure adequate voltage to fire the plugs rapidly under these conditions. Again, street driven performance vehicles seldom see this rpm-induced ignition limitation, and certainly not a GTO with an under-6000 rpm redline.

The MSD- and HyFire-type multi-spark systems typically only multi-spark up through 2500 - 3000 rpm, which is far below an engine's power peak. Thus, they do not create any benefit to peak power. In cars with big cams, running "dirty" at rpm below 3000, the multi-spark systems seem to make the plugs run a little cleaner, and I've subjectively noticed that idle quality can see a slight improvement on cars with lumpy idles. My dyno testing shows no measurable improvement in power from 2500 rpm up with the multi-spark units, so the change in rough-cam idle quality is "cosmetic" only and purely subjective on my part.

Should I start rambling about oil company profits and diesel oil now..?

Lars
 
#23 ·
Again, expertly put, Lars. As far as I'm concerned, you can ramble on about anything you want to....always a good and informative read!!!! You hit the nail on the head regarding application: 99.9% of the member's rides on this forum would be fine with the stock points iginition system provided that it was maintained and set up as originally intended. That means a tight unit with a good curve, etc, like you stated. Worn out and neglected parts are often overlooked, and when replaced with the newest super duper electro blaster, an improvement is indeed noticed. In reality, all that was needed was an overhaul of the original system. Great thread!
 
#26 ·
Let me jump in here with a brief semi-offtopic hijack, if you don't mind.

I guess this is for you, Lars --- is there a particular make/brand/type of HEI-compatible add-on rev limiter you've found to be reliable enough for street use? So far I've tried 2 different ones on my car and they've both failed. One within a month or two, the other within hours. I sent the one off and had it repaired under warranty, but I'm a little reluctant to give it another opportunity to "strand" me somewhere.

Bear
 
#27 ·
Bear -
Like you, I've had reliability problems even with the "good" aftermarket systems, so I don't completely trust them. I run a points-type ignition system in my stock GM-Delco distributors in my Judge and in my '64 Vette, and I use the points to trigger an MSD-6AL box for the rev limiter feature - just in case I miss a gear. I run both cars competitively, and I've run them both up against the rev limiters. I've had 2 MSD-6AL boxes fail on me, so I run quick-disconnect harnesses to allow me to run right off the points instead of through the CD box when the box fails... The one I haven't tried yet it the MSD 8728 soft-touch, which is supposed to work well with either points or HEI - I'm going to pick one up and try it in my HEI-equipped 463 Formula this summer.

Lars
 
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