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Who here remembers the old Sun and a few other brand names that I can't recall at the moment, distributor testers? I have been battling a flood of crappy distributors lately and sure wish I had a tester so that I can definitely tell what the problem is. I have looked for testers on-line and the only things I have found are the old 60's vintage testers. Distributors were used up until approximately 2000 and there are millions of them still on the roads. Why can I not find anything newer than 60's vintage testers? Even when I find an old Sun, they want $3000 for it. In my opinion that is absurd. If it fails and needs parts you are SOL. Tough to swallow that kind of money for something that old and unsupported. Thoughts?
Kenneth, was it a spinning distributor tester or more of an engine analyzer? Do you remember what brand it was? I've got an old engine analyzer, but I need to spin the distributor so I can see what the mechanical advance + vacuum advance are doing. Also see how stable the point plate is.
Remember them, used the Sun scope a ton. Just about every tuneup was scoped. Also used it to test coils and alternators, power balance, wire resistance etc.
We had valve grinding equipment, and a brake lathe in the shop.
Remember them, used the Sun scope a ton. Just about every tuneup was scoped. Also used it to test coils and alternators, power balance, wire resistance etc.
We had valve grinding equipment, and a brake lathe in the shop.
Same...service station I worked in H.S. had a big SUN machine. Can't even find a service station today...let alone anyone who knows how to turn brakes or know what it means.
Same...service station I worked in H.S. had a big SUN machine. Can't even find a service station today...let alone anyone who knows how to turn brakes or know what it means.
A Sun analyzer is not a Sun distributor machine, which is the topic of this thread.
Yes, people want crazy money for those old Sun distributor machines! I had one in the 1970s which I used quite often doing $15.00 or $20.00 distributor tune ups for the local crowd. I also miss the Mallory points, best and longest lasting.
I can spin it for you. PM if intersted in my offer.
Man! you lucky devil you! That looks pristine. I appreciate the offer to spin mine, but I need my own so I can try different curves and find what is best. I have 3 old cars and it would be nice to have if it won't break the bank. Well, my bank anyway.
Interesting. But without the pictures it is difficult to know what he is doing. The concept of the timing light and a tach sounds doable. Wish there were pics.
Interesting. But without the pictures it is difficult to know what he is doing. The concept of the timing light and a tach sounds doable. Wish there were pics.
I wish there were pics too, but maybe I’ll just take some time and figure it out on my own.
There were none.
Once electronic ignitions replaced points, there was no need for these machines.
Not true. You still have mechanical and vacuum advance in electronic ignitions. The electronics replaced the points only. With fully computerized ignitions, which started coming into being at around the 2000's, then you no longer had a distributor, but as long as there is a distributor there is mechanical and vacuum advance. Well, if it has vacuum advance. Could be purely mechanical.
Last edited by 69oldsguy; Nov 30, 2023 at 07:04 PM.
Not true. You still have mechanical and vacuum advance in electronic ignitions. The electronics replaced the points only. With fully computerized ignitions, which started coming into being at around the 2000's, then you no longer had a distributor, but as long as there is a distributor there is mechanical and vacuum advance. Well, if it has vacuum advance. Could be purely mechanical.
yep, until the vacuum advance went away and the ECM completely controlled added advance over base timing. I would say that became pretty much widespread by the early 80s
This is the most comprehensive article that I have seen on constructing a "shade tree" home shop distributor machine. It covers the basics required to spin and test a distributor off the vehicle and he explains it all at a level that I believe most people with a basic understanding of vehicle tune up can understand. Nice that he included pictures, charts, etc. in the original article.
Interesting. But without the pictures it is difficult to know what he is doing. The concept of the timing light and a tach sounds doable. Wish there were pics.
To see the pictures from the article
click on original link
when page loads, there are 4 icons on the upper left
the third one down looks like an open book - click on that
You already have a distributor machine. It's called your engine. Get a dial-back timing light and go to town. A vacuum pump lets you check the vacuum advance.
You already have a distributor machine. It's called your engine. Get a dial-back timing light and go to town. A vacuum pump lets you check the vacuum advance.
True enough, but I'm not a big fan of free revving my engine to 4000rpm. I don't even free rev to 3000rpm. I currently have no idea about the mechanical advance curve on the distributors I have. They may not be full in until way up there. I've seen it before. I have an advance timing light, but I don't trust that it is very accurate. At the end of the day, I may not have many choices though. Thanks everyone.
To see the pictures from the article
click on original link
when page loads, there are 4 icons on the upper left
the third one down looks like an open book - click on that
It brings you to the actual article with pictures
Thanks for that, I went to the original article on Corvette Restorer and then was able to download the entire issue in PDF. I can share it on here if anyone wants it with all the pics.
Here is a screen shot of his actual machine.
Also if you keep a eye out as I got 2 used Distributor machines a few years ago for 400 bucks, one was a 50's era Sun which worked and a Allen that needed work and flipped it for 200.
There is a company that sell restored machines and parts to restore one you have or find, all depends upon what you feel comfortable fixing.
Also if you keep a eye out as I got 2 used Distributor machines a few years ago for 400 bucks, one was a 50's era Sun which worked and a Allen that needed work and flipped it for 200.
There is a company that sell restored machines and parts to restore one you have or find, all depends upon what you feel comfortable fixing.
Regards,
Jim
Hey Jim, who is the company that sells restored units? Thanks for the pdf as well.
Not true. You still have mechanical and vacuum advance in electronic ignitions. The electronics replaced the points only. With fully computerized ignitions, which started coming into being at around the 2000's, then you no longer had a distributor, but as long as there is a distributor there is mechanical and vacuum advance. Well, if it has vacuum advance. Could be purely mechanical.
You're off by 20 years - the computer controlled distributors started in the early 1980's. The GM cars all had 7 pin HEI modules with a computer to control timing. No weights/springs/vacuum cans. You had to jumper pins on the ALDL connector to set your timing with the car running.
Originally Posted by 69oldsguy
True enough, but I'm not a big fan of free revving my engine to 4000rpm. I don't even free rev to 3000rpm. I currently have no idea about the mechanical advance curve on the distributors I have. They may not be full in until way up there. I've seen it before. I have an advance timing light, but I don't trust that it is very accurate. At the end of the day, I may not have many choices though. Thanks everyone.
I don't understand the concern with some in-car testing. I have a distributor machine and still check the distributor curve in the car from time to time to make sure nothing is stuck/broken. It takes about 10% of the time compared to pulling the distributor. It does help to have a distributor baselined so you know what to expect and know your timing light matches the Sun machine results.
The distributor testers pop up from time to time for <$500 but you gotta be checking FB Marketplace, local swap meets, etc. Paid $300 for ours with the cabinet. It works well with points distributors, but I haven't upgraded it to work with electronic ignition conversions yet. You can sink a ton of money into them.
You're off by 20 years - the computer controlled distributors started in the early 1980's. The GM cars all had 7 pin HEI modules with a computer to control timing. No weights/springs/vacuum cans. You had to jumper pins on the ALDL connector to set your timing with the car running.
In fact, first used on the 1977 Toronado 403 with the MIcro-processed Sensing And Regulation (MISAR) crank-trigger ignition system. Later seen on the Olds 260 with the C4 system in 1980 in California, which was the precursor to the CCC system (apparently to avoid confusion with the upcoming C4 Corvettes) on 307s in the 1981 model year.
Last edited by joe_padavano; Dec 5, 2023 at 06:33 AM.
In fact, first used on the 1977 Toronado 403 with the MIcro-processed Sensing And Regulation (MISAR) crank-trigger ignition system. Later seen on the Olds 260 with the C4 system in 1980 in California, which was the precursor to the CCC system (apparently to avoid confusion with the upcoming C4 Corvettes) on 307s in the 1981 model year.
Im using that 77 Toronado crank trigger wheel on my motor home with a mega squirt port injection set up.
You're off by 20 years - the computer controlled distributors started in the early 1980's. The GM cars all had 7 pin HEI modules with a computer to control timing. No weights/springs/vacuum cans. You had to jumper pins on the ALDL connector to set your timing with the car running.
At least as late as 87 there were still vacuum and mechanical advance HEI distributors being installed in new cars. That's just GM. Ford and Chrysler could be even later. I haven't checked. The point still remains that apparently there have been no distributor testers, in any great numbers, built since the late 60's if even that late. It is obvious that outside of the racing scene, no shops were tuning distributors even though the distributors existed a good 20 years later. It most likely became a throw away item. Distributor problem? Pitch it and put in a new one. I like to tinker, rebuild and maximize the performance of what was installed on my car. Who rebuilds their brake calipers, wheel cylinders and master cylinders. Most people just replace them. I enjoy messing with every part of my car.
At least as late as 87 there were still vacuum and mechanical advance HEI distributors being installed in new cars.
Which ones? Trucks maybe, which were subject to less stringent emissions requirements than were cars. I can tell you that 1986 was the last year for non-computer controlled engines in trucks over 8,600 lb GVW, per federal law (trucks under 8,600 lbs GVW were earlier). In the 1987 model year all GM one ton trucks got catalytic converters, TBI, and computer-controlled distributors. Maybe trucks over 11,000 lb GVW still had carbs and vacuum advance.
Which ones? Trucks maybe, which were subject to less stringent emissions requirements than were cars. I can tell you that 1986 was the last year for non-computer controlled engines in trucks over 8,600 lb GVW, per federal law (trucks under 8,600 lbs GVW were earlier). In the 1987 model year all GM one ton trucks got catalytic converters, TBI, and computer-controlled distributors. Maybe trucks over 11,000 lb GVW still had carbs and vacuum advance.
Parts books show an 87 G10 350 without fuel injection using the vacuum and mechanical advance distributor. Could the book be wrong? Sure it could. I don't want to get into a pissing contest with anyone Joe. My point is still that the testers faded away long before the distributors did indicating that distributors had become a throw away item.🍻
