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Discussion Starter · #1 ·
This is a "while I'm at it" chore that I'd like to get done. However there seems to be a wide range of product.

I was first thinking of converting over my tach from mechanical to electrical, but that may be a bit more wiring than I want to do.

So second is to keep the mechanical but then I need a special distributor that has the mechanical connection. I will also probably need a new tach cable and I'd probably want to get that Tachometer Cable 90-degree Adapter so I don't have such a huge S shape bend in my cable.

As for distributor, I'm confused by Ecklers. This one for $480 hei-distributor-conversion-1962-1974.html is a lot more expensive than this one for $190 hei-distributor-conversion-1962-1975.html. Why the huge price difference?
 

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Why spend the money on a new Dist. if yours is not worn out, by one of the electronic conversion kit made by either Excel, Patronix or Mallery. The bolt inside the Dist where the points would be No modifications but you will have to remove the Dist, knock out the roll pin and remove cam gear and remove shaft to install. You will have to also buy the matching coil.

This way you have electronic ignition that still looks OEM. Your shielding still fits and your mechanical tach still works

Just my nickels worth:D
 

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Read the item descriptions from Eckler's; one of the HEI units is hand prepped; the other isn't, not that it makes any difference. No HEI unit from GM was ever hand prepped.

My advice is to skip the HEI and keep the money in your pocket. If you want the pointsless conversion, get the Pertronix kit.

LectricLimited also has an electronic conversion kit if you want to look at it.

:thumbsup:
 

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If you end up adding a system where you have to remove the distributor shaft, be aware that there are 13 teeth on the distributor gear. If you put the gear back on the shaft opposite of the way it was on originally, you will have changed the orientation of the tach drive and advance can with respect to the engine by about 14 degrees. Maybe not a big deal, but it could be, if everything is stuffed under the ignittion shielding.
 

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Do not get the one from ecklers. You can get an HEI with tach drive from a company called ALL IGNITION on ebay for 99 bucks. I have had that one in my 72 for 3 years now and it runs flawlessly. If you are dead set on spending that much get one of the DUI distributers. They will curve your distributer based on the engine specs you send them.
 

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Unless I were restoring my Vette I would not buy at Ecklers. The have very good quality restoration parts, but you have to pay for them stocking Vettes only parts. Most of the powertrain in the Vette is just GM parts, and they are a dime a dozen at your local parts dealer, and wrecking yard. Any small block HEI distributor will work. Or rebuild your own and switch to a MSD electronic system and magnetic pickup, or some other brand. There are a lot of inexpensive parts out there to fit the small block chevy...
 

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Discussion Starter · #7 ·
mechanical tachometer

So I pulled off my tach cable and took a look at it as it wasn't working when I bought the car. On the end connected to the tachometer there's a red plastic piece with a square end. On the end that connected to the distributor, there was just the metal end in the shape of a square. Is there supposed to be that red plastic piece at both ends?

My uncle, who had the red '70 that inspired me, told me he replaced his once and it broke right away.

So the question is, even if I replace the tachometer cable is it going to break again right away? Or did it break because of the nasty "S" curve as it comes off the distributor? I was thinking buying that 90 degree adapter would take the "S" out and help avoid premature breaking.

My original distributor would probably be fine, but my uncle and others I have read, say that it's a definite upgrade that I should do. A lot of distributors don't have the mechanical tach option to that's why I was thinking of just ditching the whole distributor and going with a new one with HEI and an eletronic tach output.
 

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My tach cable comes out of the firewall and makes a 90 and then straight into my tach drive. It doesn't have an "S" shape. It is not bound up at all. 17 years with the same tach cable. You could get on TDC at No. 1, then remove the hold-down bolt and pull the distributor up so the distributor gear disengages from the oil pump driveshaft and the cam gear. You can then rotate the distributor housing around to get the tach drive located to take the bend out of the cable. Once you're happy with the position, you can re-align the rotor so that when the distributor is back in and flush with the intake, the rotor lines up with the No. 1 terminal on the distributor cap. Or you could re-index the plug wires on the distibutor cap to line up with the new No. 1 position as indicated by the rotor if the plug wire length doesn't allow the first option. There is no set distributor housing position or plug wire location as long as you keep the rotor and No. 1 in the correct relationship within the limits of the ignition shielding box, if you run one. (The only other thing would be if you grooved the lower ring on the distributor to shoot oil on the cam gear. You wouldn't want to move the housing too much then.)

The HEI distributors are much larger in diameter than a standard distributor. I think I would upgrade the distributor you have to non-points and keep the smaller diameter. Just my $0.02 opinion.
 

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Still got mine brand new in the box.PM me an email address and Ill shoot you some pics. Like I said $60.00 plus shipping and its yours!
 

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Discussion Starter · #10 ·
My tach cable comes out of the firewall and makes a 90 and then straight into my tach drive. It doesn't have an "S" shape. It is not bound up at all. 17 years with the same tach cable.
Here's what mine looks like now that I've pulled it out. The "S" shape was a bit worse while it was in the car.



I'll assume you're looks nothing like it. I thought I read somewhere in the AIM that the distributor was supposed to be positioned at a certain angle, something about 5:30 position like a clock. It didn't make sense to me why I can't turn the whole thing clockwise about 80 degrees. That way I'd have a nice, snooth 90 degree turn in the cable, not the mess it is right now.

Also, are both ends supposed to have that red plastic tip like I have on the left side of the picture?

Jeff
 

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Here's what mine looks like now that I've pulled it out. The "S" shape was a bit worse while it was in the car.





I'll assume you're looks nothing like it. I thought I read somewhere in the AIM that the distributor was supposed to be positioned at a certain angle, something about 5:30 position like a clock. It didn't make sense to me why I can't turn the whole thing clockwise about 80 degrees. That way I'd have a nice, snooth 90 degree turn in the cable, not the mess it is right now.

Also, are both ends supposed to have that red plastic tip like I have on the left side of the picture?

Jeff
Here are a couple of photos of my cable and distributor.





No, mine has a different shape, it is much straighter. It's straight for about 3" from the distributor end. There is some bend near the distributor end because of the large radius in the cable as it comes out of the firewall, but this bend is further away from the dizzy than yours. I just uploaded the photos.

I'm looking at page 204 of the '69 AIM and I see a note about lining up the "stake marks" and the illustration. I don't know where this orientation comes from. There is an oil hole on the distributor housing between the 2 rings, but the whole chamber is pressurized when the distributor is in place and I don't think there is an advantage to having the hole in one particular place. You can see that the stake marks position the vacuum can behind the ignition shielding bracket, maybe that's the deciding factor. I really don't know. I've run mine with the tach drive centerline essentually perpendicular to the crank centerline for 17 years with no ill effects.

If both ends of the cable were the same you couldn't get the spring cable out of the outer protective cable to replace it or lube it.

Edit: More accurate description of cable shape added and more info in 3rd paragraph.
 

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distributor

i have the PERFORMANCE DISTRIBUTORS HEI in my sb chevy.i am very pleased with it .starts first tip and runs strong.im running the 55 thou plug gap with no probs.my friend with a 74 vette is running the cheaper version from performance distributors.he is very happy with it also.if you want to remove the kink in your cable rotate the distributor 45degrees and swop the leads i position on the cap.whoever fitted the distributot didnt fine tune the positioning of the unit.

also keep buying the 99 dollar made in china crap and you will run your economy into the ground.the cheapest product is allmost allways crap wears out quickest and cant be repaired no spares available..you pays your money you make the choice
herriot ireland
 

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i have the PERFORMANCE DISTRIBUTORS HEI in my sb chevy.i am very pleased with it .starts first tip and runs strong.im running the 55 thou plug gap with no probs.my friend with a 74 vette is running the cheaper version from performance distributors.he is very happy with it also.if you want to remove the kink in your cable rotate the distributor 45degrees and swop the leads i position on the cap.whoever fitted the distributot didnt fine tune the positioning of the unit.

also keep buying the 99 dollar made in china crap and you will run your economy into the ground.the cheapest product is allmost allways crap wears out quickest and cant be repaired no spares available..you pays your money you make the choice
herriot ireland
Actually, they are made in Canada and just dont have the extreme markup that other people are charging. These use all GM parts.
http://all-ignition.com/tach-drive.html

So if I can get the exact same quality product for half the price then I am going that route. If a US company would produce the same product for the same price then I would go with them but they wont. If you want a completely made in America product buy a toyota tundra.
 

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Discussion Starter · #15 ·
whoever fitted the distributot didnt fine tune the positioning of the unit.
That about sums up *all* of the work previously done to the car before I bought it 4 weeks ago. :down:

So if the cable isn't supposed to have the red plastic item on one end and the tach didn't work, is there something in the distributor where the cable goes in that can easily break? Maybe the gear that transfers the spin from the dist shaft to the tach cable in there is stripped.
 

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Connect the cable to the dist, and start the car and see it the cable turns...
 

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The red button is a stop that keeps the cable from working it's way out of the tach. Normal rotation, the twist of the cable itself would "walk" it away from the tach.

Pull the cable off the distributor, hook a drill to it and spin the cable. carefully- figure out which way it's supposed to turn. And then light it up and watch the tach. Most common problem is the gears in the distributor-
I have the same cable that was installed at the factory- it's been lubed a couple times, but it's fine otherwise.

Nothing wrong with HEI, but I see it as something else to fail at a bad time. With points, short of something breaking, you can always tweak them to get home. Anything else dies and you get towed unless you carry spare parts.
 

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Discussion Starter · #18 ·
The red button is a stop that keeps the cable from working it's way out of the tach. Normal rotation, the twist of the cable itself would "walk" it away from the tach.

Pull the cable off the distributor, hook a drill to it and spin the cable. carefully- figure out which way it's supposed to turn. And then light it up and watch the tach. Most common problem is the gears in the distributor-
I have the same cable that was installed at the factory- it's been lubed a couple times, but it's fine otherwise.

Nothing wrong with HEI, but I see it as something else to fail at a bad time. With points, short of something breaking, you can always tweak them to get home. Anything else dies and you get towed unless you carry spare parts.
I did hook up my tach cable to my drill and attached it to the tachometer, everything works as it should. So that pretty much leaves the distributor as the culprit. So you're saying that the distributor tach gear breaking was common? Does that go even for a modern/new distributor? Otherwise sounds like a good reason to me to switch out the distributor. :D
 
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