MSD opti for less.
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Joined: Jun 2002
Posts: 485
From: Ft. Myers, Florida
Again, I had one of the first models when it came out so there was no prior knowledge to the units needing to have lock tight put on the screws or changing the screws to slightly longer ones. Pretty much stuffed it in there put 10 miles on it and fit hit the shan. What's sad is the car was under the knife for a while so by the time I got it going it was after the 12 month warranty period. Talk about a class act by MSD standing behind their product 
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Joined: Nov 1998
Posts: 71,094
From: Hell was full so they sent me to NJ
That was my immediate reaction to "exploding rotors". There are way too many LT1's being shifted at 6,300 RPM and above that do not have exploding rotors.
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Joined: Jul 2006
Posts: 974
I am going to be changing the opti next week. I am going to take the opti out tomorrow so I am going to look at that but I think it is the correct length. should be around .62 with the timing gear on correct?
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Joined: Jul 2008
Posts: 130
Try checking it with the new opti, add a small amount grease to the cam pin and install the opti and remove it if you have a grease dot in the base of wheel of the opti(bottoming out), you might want to take a little off. Metal grows when it gets hot.
Good Luck. LF
Good Luck. LF
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Joined: Sep 2006
Posts: 656
From: rhinebeck, ny
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Joined: Nov 1998
Posts: 71,094
From: Hell was full so they sent me to NJ
From Shoebox:
Before you install the cam, it is a good idea to check the dowel pin length. Compare the new length to the old and make any adjustments if needed. If the dowel pin is too long, it can ruin a vented optispark in a short time (non-vented optisparks aren't driven by the dowel pin). GM specs indicate that the dowel should be .620" long (protrusion from the front face of the cam) for the vented optispark. Some people have said it is supposed to be .685". Mine was actually .650" and still was in no danger of bottoming out in the optispark drive (I'm thinking .685" might be the max it could be). Here you can see the difference in the Comp Cams dowel (right) to the original. The CC pin was .840". That would put pressure on the back of the optispark and destroy it in a short time. If you have any doubts about the length, use some modeling clay (even PlayDoh :-) ) to test fit the opti and check the clearance. Comp Cams advises you to check all clearances.
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Joined: Jan 2007
Posts: 1,027
From: Lansing, MI via Bowling Green, KY: Dalton, GA: Nashville, TN & Atlanta, GA
I considered getting an MSD when I replaced my factory original opti. In hindsight, I'm pretty happy that I decided to go with another GM piece.
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Joined: Sep 2006
Posts: 271
From: TN
i had got one of the accel opti. for my car when they came out and it lasted i think 9 miles. the rotor exploded in pieces and was forced into the cap. replaced the cap and rotor twice after that with the same results but got only 25 miles. after this i took it completely off the car and measured the dowel and it was almost a quarter inch longer then my original gm opti. i put the gm back on and it was fine with no problems. i will never buy the accel again. thats when they first came out years ago
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Joined: Aug 2006
Posts: 3,705
From: Kansas
while your in there, id just go ahead and do the whole unit. Doing just cap/rotor is fine, but why go through the hassle when 5k down the road the opti could go out, and than you would have a brand new cap/rotor thats worthless once you have to buy the new opti anyways?
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Joined: Jul 2006
Posts: 974
Ok, I got everything done. I checked the cam pin length with some blue silicone and it is far from bottoming out on me. I used thread locker on the new msd rotor screws also. I went ahead and installed new wires while I was down there. The MSD opti seems to be made a lot better to. Bad news is my rough idle issue is still there.
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Joined: Jul 2004
Posts: 1,174
From: MI
I have always had problems with rotor destruction on GM and other brand opti units. I have come to the root cause (plastic rivet melts) of this when use of high energy ignition is used (ie... MSD 6 and 8202 coil). I always rivet the rotor with 1/8" alum. I think, very hot in there with the MSD ignition, but I need this energy for my app. I lost an encoder on a Summit opti recently (1 + year). I have replaced it with an all-ignition.com performance unit (it was 300 dollar). It looks like the MSD unit inside. I had trouble with the timing, but, I have adjusted it and fine tuned it with a MSD variable timing control. It has responded well under load. (App... 97ss 383 D1 MM6) B.
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