Advanced Opti Thread.
Thread Starter
Le Mans Master
Joined: Feb 1999
Posts: 9,922
Likes: 38
From: South Carolina
St. Jude Donor '03 & '05
I think the torx, inverted, are E4 and E5 size. Can you send pics with the cap off and rotor off. If you take the rotor off, for example, you need to put a spacer in there somewhere, to compensate for the rotor being gone. I just receieved an Opti to use, and will be looking at taking the rotor out this weekend, for my DELTEQ use. I shift at 6300rpm, porbably low for my motor, but...
Also, how thick is your cam gear, is it the OEM? Extreme Duty? I have an OEM I can measure later when I am home?
Also, how thick is your cam gear, is it the OEM? Extreme Duty? I have an OEM I can measure later when I am home?
Last edited by steve40th; Oct 19, 2005 at 12:26 PM.
Drifting
Joined: Dec 1999
Posts: 1,330
Likes: 36
From: Waynesboro, PA
Co-winner 2020 C4 of the Year - Modified
Yeah, the 4 screws that hold the cap to the body are E4 inverted Torx, but the 2 screws that hold the rotor on are T9 Torx (I just got a set today, T5-T10). I have the LT4 Extreme Duty timing set. I just removed them and put red loctite on the threads tonight. I didn't take any pics yet, though. I'll try to in the next few days, and email them to you.
Darren
Darren
Thread Starter
Le Mans Master
Joined: Feb 1999
Posts: 9,922
Likes: 38
From: South Carolina
St. Jude Donor '03 & '05
Originally Posted by POLOVETTE 94
Yeah, the 4 screws that hold the cap to the body are E4 inverted Torx, but the 2 screws that hold the rotor on are T9 Torx (I just got a set today, T5-T10). I have the LT4 Extreme Duty timing set. I just removed them and put red loctite on the threads tonight. I didn't take any pics yet, though. I'll try to in the next few days, and email them to you.
Darren
Darren
Drifting
Joined: Dec 1999
Posts: 1,330
Likes: 36
From: Waynesboro, PA
Co-winner 2020 C4 of the Year - Modified
Yup. The E4 inverted Torx fits the 4 screws holding the cap to the distributor assembly. On the inside, there are 2 screws with T9 Torx heads holding on the rotor. At least that's how it is on mine. My car is converted to the 95 style timing cover and opti, I'm not sure about the 92-94.
Darren
Darren
Racer
Joined: Jan 2005
Posts: 418
Likes: 45
From: Houston Texas
I'm in the middle of replacing my opti. Haven't got there yet (still at the damper removal...) but I heard that the torx screws that hold the black plate on the top of the throttle body will fit. Remove one, hold it with vise-grips and you have your inverse torx.
Thread Starter
Le Mans Master
Joined: Feb 1999
Posts: 9,922
Likes: 38
From: South Carolina
St. Jude Donor '03 & '05
Originally Posted by DMGroh
I'm in the middle of replacing my opti. Haven't got there yet (still at the damper removal...) but I heard that the torx screws that hold the black plate on the top of the throttle body will fit. Remove one, hold it with vise-grips and you have your inverse torx.
But inside my rotor was held by flat tip screws, with real fine threads.
Now I just need to see how much of a spacer or what to use as a spacer since I am taking the rotor out, but am leaving the optical sensor plates in. And they are held in by the rotor.
Racer
Joined: Jan 2005
Posts: 418
Likes: 45
From: Houston Texas
Just got inside my opti and found the source of my problem. 1 of those tiny torx screws holding the rotor backed out and was laying around inside there. With only 1 screw holding the rotor, it can flex quite a bit and caused the violent jerking/miss I had. The screw that fell out was not nicked or beat-up, so I believe the problem was from the rotor flexing. There were no carbon traces, but the contacts on the cap were screaming for replacement. Sure glad I went in there.
Question for the "Wiser/Better Informed/Experienced more problems than I have (yet)": Should I take out the rotor screws from the new GM opti and loc-tite them? Would they already have loc-tite? Any advice here?
Comment on a 10 year old rotor. I was surprised at how much the plastic had deteriorated..it was about to break into pieces and there were no signs of blunt force trauma. If you guys are upgrading to an aftermarket unit and decide to keep the rotor in there as a spacer, you might want to think twice about re-using the old rotor.
Question for the "Wiser/Better Informed/Experienced more problems than I have (yet)": Should I take out the rotor screws from the new GM opti and loc-tite them? Would they already have loc-tite? Any advice here?
Comment on a 10 year old rotor. I was surprised at how much the plastic had deteriorated..it was about to break into pieces and there were no signs of blunt force trauma. If you guys are upgrading to an aftermarket unit and decide to keep the rotor in there as a spacer, you might want to think twice about re-using the old rotor.
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Thread Starter
Le Mans Master
Joined: Feb 1999
Posts: 9,922
Likes: 38
From: South Carolina
St. Jude Donor '03 & '05
Team Owner
Joined: Mar 2001
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From: Boston, Dallas, Detroit, SoCal, back to Boston MA
Id like to see how many people with opti problems after modification have and aftermarket keyed balancer hub. Why? The factory balancer hub is NOT KEYED to the crank. Some LT1's were actually balanced hot, with the engine running. After modification, this balanced is lossed. So the extra vibrations can damage it.
Thread Starter
Le Mans Master
Joined: Feb 1999
Posts: 9,922
Likes: 38
From: South Carolina
St. Jude Donor '03 & '05
Originally Posted by BrianCunningham
Id like to see how many people with opti problems after modification have and aftermarket keyed balancer hub. Why? The factory balancer hub is NOT KEYED to the crank. Some LT1's were actually balanced hot, with the engine running. After modification, this balanced is lossed. So the extra vibrations can damage it.
I think that the vibrations play a big part, but the cheap way its made doesnt help.