[jamaca85]

Has anybody ever had a rotor come loose on them in an HEI? My car was having a problem with a little bit of a sputter at 5,000 RPMs and when I would come back to the pits after a run it would idle real high. I finally narrowed it down by taking off the cap on the distributor and looking inside the distributor in realizing that the rotor had come loose. The screws had backed out like about couple turns each just enough to make the rotor wobble back and forth and I guess the high idle was because of the weights getting stuck open on the distributor because of the rotor. I checked the distributor in the shaft is okay put a new rotor and cap in it seems to have solved the problem with the high idle... Just one of those things I guess

[soupman]

The only issue I have had with some rotors is the inside diameter being a hair small. It wouldn’t allow the weights to sling outward far enough for full advance. The weights would hit the internal insides of the rotor wall and had to be shaved some. Took awhile to figure that one out.

[steve25]

To keep the screws from potentially backing out again if you have some fishing line cut a short section off and place it in each screw hole before you place the screws in and the line will act like a nylock screw.

[b-man]

Loctite is your friend.

The small screw purple thread locker 222MS would be appropriate for that size screw.

[steve25]

And that size bottle is at least 35 bucks when you on,y need two drops, lol!

[b-man]

Got that big bottle for free, my former workplace wasn’t allowed to keep using them after the expiration date even though it would still work just fine. I have quite a few bottles of different types.

In the medical device industry that I’m now retired from they disposed of perfectly good chemicals after a predetermined date because of the liability issues.

Buy the tiny tube or bottle, in places where you have fasteners loosening from vibration you definitely should use it.

Lol.

[steve25]

I was just poking some fun, but, dam look at what the price is of even the small bottle as I just did.

My bottle I have must be an easy 10 years old, but still seems to work just fine.

[Formulas]

I would be willing to bet the screws were not sufficiently tight at install

[steve25]

How much do the screws rock around when fully engaged in there threads?

Might be time to tap for a Metric size machine screw?

[b-man]

Originally Posted by Formulas

I would be willing to bet the screws were not sufficiently tight at install

Me too, I’ve never had a rotor come loose.

But a little drop of low-strength Loctite will make sure it won’t come loose.

At one of my previous jobs we built 3, 5 and 10KV power supplies and pretty much every screw had Loctite on the threads. Screws would eventually come loose inside and cause failure so it was mandatory.

[jamaca85]

I'm just happy I found it before it got worst. I was probably talking on the phone or something the last time I messed with the cap and rotor like 4 years ago .

[Half-Inch Stud]

Had the loose HEI rotor discovery before, so became picky about the choice of rotor screws.

Easy to blame a clapped-out mount plate, or an unseated rotor.

Where they shiney philips head or dull 1/4" hex head?

[jamaca85]

Philips.....black...I changed the cap and rotor and put a dab of thread lock on them....but I will be making it a part of my spring refresh to check the dam thing...

[Half-Inch Stud]

The 1970 HEI original rotor screws may have been 1/4" hex head and seems to stay put.

[Formulas]

I have even used nylon 10/32 screws on rotors and they stayed put

If one wanted a over the top install a screw from the bottom loctite in place then a nyloc nut on top