MSD 8381 Optispark Performance
Thread Starter
Pro
Joined: Aug 2007
Posts: 668
Likes: 38
From: Austin TX
MSD 8381 Optispark Performance
This is a log of mileage and performance of the MSD 8381 Optispark and MSD 8226 Coil in my 92 Z07 base model Corvette. I am not affiliated with MSD in any way. Just a consumer willing to air the good and the bad. I will let you know if it fails.
I currently have 4000 miles on the products and so far neither product has failed and both are performing as designed. And that is a good thing..
I did put a timing light on my ignition system recently and can note that the timing is dead on as compared with a factory opti and consistent.
I currently have 4000 miles on the products and so far neither product has failed and both are performing as designed. And that is a good thing..
I did put a timing light on my ignition system recently and can note that the timing is dead on as compared with a factory opti and consistent.
Last edited by mixalive; Sep 10, 2019 at 10:07 AM.
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
This is a log of mileage and performance of the MSD 8381 Optispark and MSD 8226 Coil in my 92 Z07 base model Corvette. I am not affiliated with MSD in any way. Just a consumer willing to air the good and the bad. I will let you know if it fails.
I currently have 4000 miles on the products and so far neither product has failed and both are performing as designed. And that is a good thing..
I did put a timing light on my ignition system recently and can note that the timing is dead on with the factory setting and consistent.
I currently have 4000 miles on the products and so far neither product has failed and both are performing as designed. And that is a good thing..
I did put a timing light on my ignition system recently and can note that the timing is dead on with the factory setting and consistent.
Race Director
Joined: Sep 2001
Posts: 14,670
Likes: 749
From: NEwhere Ohio
Nice to hear you are having good luck with msd. It seems that the msd failures occur within first 1000 miles. I think you are over the hump.
All the msd failures and no one documents wwhat broke in it...
Nice to hear a datapoint of it working.
All the msd failures and no one documents wwhat broke in it...
Nice to hear a datapoint of it working.
Thread Starter
Pro
Joined: Aug 2007
Posts: 668
Likes: 38
From: Austin TX
Well the 8381 is still working at about 10000 miles. But I would like to report a situation I had with it recently. I had been having issues in the wet weather when hitting small puddles of water, that the engine would die. After letting it set for 30 min or so, it would reluctantly start back up. After talking to the technicians at MSD. They informed me that the unit should maintain a vacuum if a vacuum is pulled on both vents at the same time. I tested this and determined mine did not maintain a vacuum. They sent me a new cap and seal. Upon install, I applied silicone sealant to the seal, let set overnight and retested for vacuum. I found vacuum being lost at the connector pigtail pass through. I silicone sealed that area, let set overnight and retested. It now maintains a vacuum. The old seal showed signs of fluid being drawn into the optispark from the bottom. It seems to be doing the job now.
I did not find in our forum where a vacuum test should precede re-assembly during an Opti installation procedure. Nor did I find it in MSD's installation instruction manual. So I would suggest in any Optispark Installation, verifying for a maintained vacuum before putting your car back together.
I did not find in our forum where a vacuum test should precede re-assembly during an Opti installation procedure. Nor did I find it in MSD's installation instruction manual. So I would suggest in any Optispark Installation, verifying for a maintained vacuum before putting your car back together.
Last edited by mixalive; Sep 10, 2019 at 10:10 AM.
Melting Slicks
Joined: Sep 2003
Posts: 2,270
Likes: 118
From: N. Babylon NY
Well the 8381 is still working at about 10000 miles. But I would like to report a situation I had with it recently. I had been having issues in the wet weather when hitting small puddles of water, that the engine would die. After letting it set for 30 min or so, it would reluctantly start back up. After talking to the technicians at MSD. They informed me that the unit should maintain a vacuum if a vacuum is pulled on both vents at the same time. I tested this and determined mine did not maintain a vacuum. They sent me a new cap and seal. Upon install, I applied silicone sealant to the seal, let set overnight and retested for vacuum. I found vacuum being lost at the connector pigtail pass through. I silicone sealed that area, let set overnight and retested. It now maintains a vacuum. The old seal showed signs of fluid being drawn into the optispark from the bottom. It seems to be doing the job now.
I did not find in our forum where a vacuum test should precede re-assembly during an Opti installation procedure. Nor did I find it in MSD's installation instruction manual. So I would suggest in any Optispark Installation, verifying for a maintained vacuum before putting your car back together.
I did not find in our forum where a vacuum test should precede re-assembly during an Opti installation procedure. Nor did I find it in MSD's installation instruction manual. So I would suggest in any Optispark Installation, verifying for a maintained vacuum before putting your car back together.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Thread Starter
Pro
Joined: Aug 2007
Posts: 668
Likes: 38
From: Austin TX
Failure at around 30000 miles on the MSD 8381. I lose the Hi Resolution voltage and SES light comes on after the engine warms to past 154*F water temp. This verified today with an oscilloscope. My MSD 8226 coil failed at 20000 miles.
Melting Slicks
Joined: Sep 2003
Posts: 2,270
Likes: 118
From: N. Babylon NY
Which direction are you considering now?
Steve
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
But it reads like you made a objective report here and I can see you have the skills to do it correctly. Thx for the report and all your efforts here - valuable to us all.
My second thought here is I wonder if a positive pressure air supply system just for the opti could help most of them live longer than the rotor bearings? Just a small flow of clean air flow but above atmospheric pressure to keep pushing air, heat and particles out any leaks instead of inward to the intake system.
Something like a little aquarium tank air pump could do the job. Problem is we dont really know if its contamination or just plain heat thats killing the opti sensors.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
My NAPA unit that I installed 4/12 is still working great.
Who knows, but mine did the SAME THING, only mine had to get up to over 200* for it to fail.
Instructor
Joined: Jun 2016
Posts: 213
Likes: 59
From: North Augusta, South Carolina
I must be really unlucky. I have been through two MSD Optis before I returned the last one for a full refund. The first one lasted 9 months (put about 10K miles on the first MSD Opti) and the replace meant for that wouldn't idle correctly and died when I tried to back the car off the lift. I'm currently deciding on if I want to spend the money and try out the LTCC conversion.
Thread Starter
Pro
Joined: Aug 2007
Posts: 668
Likes: 38
From: Austin TX
I sent the MSD 8381 back to MSD over the holidays for repair. Oil had migrated into the unit. They cleaned and replaced the optical sensor with an updated unit for $150 to include return shipping. Finished reinstalling yesterday with a new water pump. It runs good so far.
I did a pressure check before install and found it to leak at the 3 screw ends on the back side of the unit as well as the timing adjust screw, wire inlet passage and the caps o-ring. I silicon'd and was able to get the unit to seal. I also installed a barbed spigot and rubber hose to the water pump drain hole to divert fluid in case of coolant blowout.
I did a pressure check before install and found it to leak at the 3 screw ends on the back side of the unit as well as the timing adjust screw, wire inlet passage and the caps o-ring. I silicon'd and was able to get the unit to seal. I also installed a barbed spigot and rubber hose to the water pump drain hole to divert fluid in case of coolant blowout.
Last edited by mixalive; Jan 4, 2017 at 12:30 PM.
Melting Slicks
Joined: Sep 2003
Posts: 2,270
Likes: 118
From: N. Babylon NY
I sent the MSD 8381 back to MSD over the holidays for repair. Oil had migrated into the unit. They cleaned and replaced the optical sensor with an updated unit for $150 to include return shipping. Finished reinstalling yesterday with a new water pump. It runs good so far.
I did a pressure check before install and found it to leak at the 3 screw ends on the back side of the unit as well as the timing adjust screw, wire inlet passage and the caps o-ring. I silicon'd and was able to get the unit to seal. I also installed a barbed spigot and rubber hose to the water pump drain hole to divert fluid in case of coolant blowout.
I did a pressure check before install and found it to leak at the 3 screw ends on the back side of the unit as well as the timing adjust screw, wire inlet passage and the caps o-ring. I silicon'd and was able to get the unit to seal. I also installed a barbed spigot and rubber hose to the water pump drain hole to divert fluid in case of coolant blowout.
Did you have an oil leak out of the timing cover/seal or intake?
Thanks for the update.
Steve