LTCC problem
02-22-2016 | 11:30 AM
#16
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Joined: Nov 1998
Posts: 70,853
From: Hell was full so they sent me to NJ
Re: LTCC problem
That's good to know about the MSD cap and rotor - Ill look into doing that. Just speaking with people/mechanics, I've come across people that say the LTCC isn't worth it because it still uses the opti spark low voltage. The reason why I did it was because I read that since the high voltage is redirected through coils, the opti has less of a chance of getting overheated and lasts longer.
The big problem with the 93/94 UNVENTED Opti is the fact that the high voltage discharge within the cap/rotor causes the formation of ozone. Ozone promotes corrosion. That is the reason for all the rust buildup in the unvented units. That is the documented reason GM added the vent system - to clear out the ozone. Remove the high voltage function and ozone from the Opti = no rust, and the optical cam position sensor has a very easy life. My unvented Opti became erratic at about 40,000 miles, due to rust buildup blinding the optical sensors in the module. I switched to a vented unit when the stroker was built in 2000, installed an aftermarket ECU that accepts the Opti's cam position signals (just like the LTCC does). No more problems 16 years later. And this is an Opti that exists in an engine that has a 7,200 RPM redline, and needs a killer ignition to fire the plugs with a 300-shot of nitrous. I have documented two occasions where a missed shift (car was originally an M6) has resulted in the engine reaching 8,000 RPM. Opti cam position sensor took a lickin' and kept on tickin'.
I did not swap to the vented unit because I wanted the vent. I swapped to the vented unit because I wanted to use the LT4 Extreme Duty timing set to handle a solid roller camshaft with very high spring pressures, and that timing set only works with the pin drive, vented Opti. It does not have the splines in the cam sprocket hole to drive the splined shaft of the unvented Opti.
02-23-2016 | 08:25 AM
#18
Thread Starter
Registered User
Joined: Jan 2016
Posts: 29
From: FL
Re: LTCC problem
That swap is a pretty substantial undertaking - wiring harness, vacuum harness, timing cover, timing set, new cam. Cheaper to buy an unvented AC Delco, then get an MSD cap and rotor, which is vented for both 93/94 and 95-97.
Shoebox has it covered:
4th Gen LT1 F-body Tech Articles
AC Delco has also complicated the issue of replacing the rivets, loc-titing the screw by sealing the case and voiding the warranty if the seal is broken.
Shoebox has it covered:
4th Gen LT1 F-body Tech Articles
AC Delco has also complicated the issue of replacing the rivets, loc-titing the screw by sealing the case and voiding the warranty if the seal is broken.
02-23-2016 | 08:35 AM
#19
Thread Starter
Registered User
Joined: Jan 2016
Posts: 29
From: FL
Re: LTCC problem
Has nothing to do with "overheating".
The big problem with the 93/94 UNVENTED Opti is the fact that the high voltage discharge within the cap/rotor causes the formation of ozone. Ozone promotes corrosion. That is the reason for all the rust buildup in the unvented units. That is the documented reason GM added the vent system - to clear out the ozone. Remove the high voltage function and ozone from the Opti = no rust, and the optical cam position sensor has a very easy life. My unvented Opti became erratic at about 40,000 miles, due to rust buildup blinding the optical sensors in the module. I switched to a vented unit when the stroker was built in 2000, installed an aftermarket ECU that accepts the Opti's cam position signals (just like the LTCC does). No more problems 16 years later. And this is an Opti that exists in an engine that has a 7,200 RPM redline, and needs a killer ignition to fire the plugs with a 300-shot of nitrous. I have documented two occasions where a missed shift (car was originally an M6) has resulted in the engine reaching 8,000 RPM. Opti cam position sensor took a lickin' and kept on tickin'.
I did not swap to the vented unit because I wanted the vent. I swapped to the vented unit because I wanted to use the LT4 Extreme Duty timing set to handle a solid roller camshaft with very high spring pressures, and that timing set only works with the pin drive, vented Opti. It does not have the splines in the cam sprocket hole to drive the splined shaft of the unvented Opti.
The big problem with the 93/94 UNVENTED Opti is the fact that the high voltage discharge within the cap/rotor causes the formation of ozone. Ozone promotes corrosion. That is the reason for all the rust buildup in the unvented units. That is the documented reason GM added the vent system - to clear out the ozone. Remove the high voltage function and ozone from the Opti = no rust, and the optical cam position sensor has a very easy life. My unvented Opti became erratic at about 40,000 miles, due to rust buildup blinding the optical sensors in the module. I switched to a vented unit when the stroker was built in 2000, installed an aftermarket ECU that accepts the Opti's cam position signals (just like the LTCC does). No more problems 16 years later. And this is an Opti that exists in an engine that has a 7,200 RPM redline, and needs a killer ignition to fire the plugs with a 300-shot of nitrous. I have documented two occasions where a missed shift (car was originally an M6) has resulted in the engine reaching 8,000 RPM. Opti cam position sensor took a lickin' and kept on tickin'.
I did not swap to the vented unit because I wanted the vent. I swapped to the vented unit because I wanted to use the LT4 Extreme Duty timing set to handle a solid roller camshaft with very high spring pressures, and that timing set only works with the pin drive, vented Opti. It does not have the splines in the cam sprocket hole to drive the splined shaft of the unvented Opti.
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