Cheap HEI distributor question

[Gungho]

I bought a cheap HEI distributor from an auction website (not sure of rules with mentioning website names) about a year ago before I knew better. The Jeep has been running fine, but I’m scared it’s doing damage after reading more. Some say only a problem for V8’s and not the 258. Is there a way to tell if the one I have has too hard of a gear? And will a DUI or msd run better (worth the extra money).

This site has been great with helping me learn. Thanks for all the input!

 

[JeffP]

I bought a cheap HEI distributor from an auction website (not sure of rules with mentioning website names) about a year ago before I knew better. The Jeep has been running fine, but I’m scared it’s doing damage after reading more. Some say only a problem for V8’s and not the 258. Is there a way to tell if the one I have has too hard of a gear? And will a DUI or msd run better (worth the extra money).

This site has been great with helping me learn. Thanks for all the input!

I’m guessing that you got the copy of the typical GM HEI and are worried over the cast iron Vs steel drive gear.
I’ve used over half dozen of those and have never had an issue, furthermore I’ve never seen or even heard of one with a steel gear.
The next thing... when you bought it, the listing likely gave an engine size and year range. I’m sure the details matched your Jeep at the time or you wouldn’t have bought it.
Lastly... it wouldn’t take this long to have destroyed your cam if you were running a steel gear. Relax... it’s fine.
Now that is settled, I’ve never seen one of those where the vacuum advance was correct. In every case I’ve had better performance leaving that disconnected. Set your ignition timing with it disconnected! Run it up to highway speed and see if it’s better... bet it is.

 

[Torxhead]

Actually Jeff, there is a history of bad distributor drive gears for the HEI ignition. A short while back and possibly still currently, there are HEI distributors available from China that have a drive gear that is harder than the mating cam gear. Gungho, you could remove your distributor and look down at the camshaft gear and inspect it for excessive wear. It works both ways as the aftermarket distributor gear could be too soft and it would wear down at that location. This website does have a few stories of this issue.

 

[mtnwhlr]

My '78 that I bought a while back wasn't running because the PO installed a cheap HEI distributor and it ate the cam gear. But I have only heard if this happening on the 304s.

 

[JeffP]

Actually Jeff, there is a history of bad distributor drive gears for the HEI ignition. A short while back and possibly still currently, there are HEI distributors available from China that have a drive gear that is harder than the mating cam gear. Gungho, you could remove your distributor and look down at the camshaft gear and inspect it for excessive wear. It works both ways as the aftermarket distributor gear could be too soft and it would wear down at that location. This website does have a few stories of this issue.

Good to know! I’ve only used one on a 304. (Bought it with that installed) Fortunately I didn’t have any trouble with it until I put it back the way it left the factory.
Replacing a distributor gear is no big deal, my concern would be the metal that came off circulating with the oil, destroying everything else. I wouldn’t wish that on someone I didn’t like. Well in-laws maybe.... nahh not even them.
I have used quite a few on small block Fords with great success.
Since I started making my own “ignition boxes” the best combination I’ve found is the Ford Duraspark distributor with my own box or MSD box.
For AMC, I’m using a point type distributor with the “Pertronix Ignightor” feeding my own or MSD box. Both systems are performing quite well.

 

[007]

Regardless of what distributor you use, if you're leary of your gear it's best to get the "correct" distributor and swap gears. Well worth the price of the distributor at Napa or wherever. When I went to the MSD ProBillet distributor to fix timing control issues with my Sniper, I swapped gears...just to be sure.

 

[Dan77CJ7]

Good to know! I’ve only used one on a 304. (Bought it with that installed) Fortunately I didn’t have any trouble with it until I put it back the way it left the factory.
Replacing a distributor gear is no big deal, my concern would be the metal that came off circulating with the oil, destroying everything else. I wouldn’t wish that on someone I didn’t like. Well in-laws maybe.... nahh not even them.
I have used quite a few on small block Fords with great success.
Since I started making my own “ignition boxes” the best combination I’ve found is the Ford Duraspark distributor with my own box or MSD box.
For AMC, I’m using a point type distributor with the “Pertronix Ignightor” feeding my own or MSD box. Both systems are performing quite well.

What box are you making? I always like new information on ignitions.