i will be putting mine one before the motor goes back into the car. so i am going to check the gasket more than 10 times and locktite the hell out of the bolts. i might have 1 day i can spare to see if i can trace down some longer bolts, after i measure the depth of the hole. good write up SweetZRag

 

What about the issue of the rotor screws getting loose??? Your report does not address that issue. And the loose rotor screw problem is one of the more common MSD failures.

For example; In talking with Chad Golen he told me, "the first MSD distributor they had on an engine on the dyno (with solid motor mounts) the rotor fell off during the first dyno run."

Possibly a mild street LT engine w/ a small cam might not have the problem with the rotor screws getting loose. However, with the larger cams (.550” + lift) and stronger valve springs, the valve train vibration is significantly increased!

WD

 

I am not making any crazy HP so maybe its why i have made it 5000 miles with no problems. The cam is stock and i never did anything but tighten down the screws. I think some already had threadlock on them. I still think the cam being aftermarket can cause the rotor to set bad and rub. One good thing is if something goes wrong i will just go right after the opti and at least check it out.

 

The O-ring if installed incorrectly will push against the black housing and force the tabs of it inwards, allowing it to ride up and rub against the rotor. There really isn't much of a lip on the billet aluminum base so the O-ring slips up easily. You likely haven't had a problem because your o-ring didn't slide off the base, but... let's be realistic: the o-ring may be efficient at sealing out water but it is a very impractical gasket given the way it slides off the lip.

I believe now that incorrect O-ring installation may have been my problem, compounded by a poorly secured housing thanks to a bad design. The best advice I can offer those here who are installing the MSD unit is to secure the housing and make sure the O-ring is installed correctly - better still, ditch the O-ring in favor of RTV form-a-gasket that will seal better anyway.

 

I hadn't read the entire post when I responded so I didn't see the issue of screws not holding. Also, I agree with the Engineer's assessment that the O-Ring, if not seated properly, could cause inward pressure causing the locking tabs to release allowing the inner housing to move forward rubbing the bottom of the rotor.

I installed the cap before I put the Opti in the car so I could get a good view of the O-Ring all the way around as I seated the cap. I recommend this approach rather than installing the cap after the Opti is installed.

Does anyone know the torque spec for the rotor scews? Since it is sold as a serviceable part, the proper torque should be provided. I am curious how tight it is supposed to be. Also, given everyone's problems with the rotor screws, I would use Loctite red also.

For those of you having the problem, complain to your retailer. They can put a lot more pressue on the manufacurer than an individual. I sent my report to Summit.

 

The blue thread-locker didn't hold last-time around on my MSD, and the #6-32 machine rotor screws “were” tightened correctly. This time the rotor lasted about four bracket races (35-40 runs).

Additionally, the #6-32 screws provided with the MSD distributor "should be" slightly longer to catch a few more threads in the rotor hub. However, there is only a few thousandths clearance (possibly only .040”) between the rotor hub the aluminum case. I picked-up some longer #6-32 Allen socket-heads yesterday to experiment with the length. Also, I may use a flat washer with the Allen heads and red thread-locker for sure.

In talking with MSD this week they said, "their engineering department is working on the loose rotor screw issue and may already have a fix." And that is very good news! They finally admitted to me there is a problem with the rotor screws getting loose (other than my car). I can’t stand it when people are not honest and forthright with me, particularly on technical issues!

WD

 

ok i just got mine and went through it. i have .035 clearance under the rotor button. i also used a good amount of permatex high strength thread locker red on the rotor button screws. WD i did notice some material , gray in nature, on all the threads. both the rotor buttons and the cap screws. i cleaned out the material in the rotor button holes, before adding my thread locker. i heated the o-ring in some hot tap water and streched it. when the cap seated i didn't hear the o-ring smack the plastic, like it does when it slips off. i tighted the cap screws in a criss cross pattern , adding more torque in a total of 3 passings. i also took a photo of the clearance under the rotor button before install. lets see if it holds together in a high hp application.

 

My update: Took my MSD appart after reading this thead since I've been chasing a high RPM drop out in power that occurs at 5500RPM. Sure enough one of the rotor screws had backed right out just like the pics in this thread but the other one was tight and there was no rubbing. I must say I'm pretty blown away that the blue loctite didn't hold in the screws for the engineers Opti.

I'll be talking to MSD tomorrow as well.

 

I'll tell you why i'm still p'd off. Next week I'll head back to school and realistcally wont drive the car until next summer, at which point the warrenty will be up. My luck, the opti will finally take a crap, and i'll be stuck dishing out $150 to purchase their cap and rotor kit. BS!!!!!!!!!!!!!!
Do you think they will go as far as to issue a recall on the product? I can only wish!

 

when i bought mine 20k ago i first took it apart and put loctite on all the screws i could take out on the whole thing, havnt had a problem yet the car still runs perfect.

 

I purchased a Dynaspark for a 97 LT1. The housing did not fit the engine cover. I took it completely apart and machined the billet alum housing to fit the timing cover. Also, the Dynasparkk uses same gm rotor with only one rivet. The contacts had copper corosion on them. A waste of money ($590), and, once you take it apart (they had tamper-proof fasteners), you own it. No support for the vendor.

Since then I went thru 3 gm optis. Now I completely rebuild them. Also, the gm stock rotor screw is a metric piece. The rotor mount is an oil hardened steel. I normalize it and re-tapped for a 4-40 American screw. This works better since it has more threads, and, American. Im running a 6A msd with 8202 coil. Every opti rotor contact is reworked to receive two (2) alum rivets. The sonic welded plastic joint just does not hold up to the heat.

I also eliminated the vent filter. No flow with that thing (very restrictive). I've got it open with the other side taped into my blower intake suction side. Opti's must get very hot in there.

Now working on my own rotor design, and, I have had some hard lessons.

Since then, I have not had a failure and it runs past 6800 rpm.
Thankyou for all your experiences. "Opti is like a box of chocolates. You never know what your going to get. (usually crap)"
Hope this helps... (97ss 383 - D1) B.

 

The “root cause” of the MSD rotor screws getting loose (by my determination) is due to the rotor “not having a tight press fit” on the distributor shaft hub. There is about five thousands (.005) clearance difference between the shaft hub OD and the rotor’s ID. That in-turn places the total mechanical load of the rotor on the two #6-32 machine screws.

If the rotor had a tight “press fit” on the shaft hub (like several old model distributors), that would provide the mechanical stability for the rotor and “remove” the load and vibration from the two #6-32 machine screws. Which in-turn causes the rotor screws to vibrate loose.

The last time I had my MSD opti out, I reinstalled the rotor with some different and slightly longer #6-32 machine screws (stainless steel Allen socket-head) and added a flat washer. Also, I learned the green thread-locker is designed to be used on small diameter machine screws.

The new Allen screws doesn’t fix the cause of the problem (loose rotor fit on shaft hub), however, the longer Allen socket screws w/ washers can be tightened much more then a Phillips head screw. Additionally, the longer screws should catch a few more threads in the hub (over the short MSD rotor screws), just make sure the longer screws don’t extend through the hub and rub the aluminum housing.

Here are some photos.

WD

 

When i got it all together i looked at the side and noticed the washer was pressed more on one side than the other. I went to take it apart and evenly tighten the thing back down. The screws were so cheap that it would have stripped them to back them out and it wasn't that bad so i left it. Maybe the uneven fit works best.

 

If the distributor cap doesn't fit-down flat (flush) on the Aluminum distributor housing, I would be concerned. Additionally, the O-ring seal gasket (hopefully the square one) must be seated correctly on the housing lip for the cap to fit flush.

WD

 

I also have experienced the loose screws problem. I also added blue thread lock to it but I have yet to restart the motor and see how long that lasts. I wish I had noticed this thread sooner and realized that the blue stuff isn't going to fix the loose screws. Are there any updates on what MSD is doing to resolve this problem?