Opti-Spark Cap and Rotor Risk or Reward?
01-31-2016, 12:12 PM
#1
Safety Car
Thread Starter
Opti-Spark Cap and Rotor Risk or Reward?
If you saw this thread I posted https://www.corvetteforum.com/forums...e-pattern.html
you know my current (likely original) Opti-Spark is working 100%.
Given how I use the car (auto-x/track days) would you:
1.Pull the Opti-Spark to inspect bearing/replace cap and rotor/seals to ensure its life at higher RPM (assuming the unit is 23 years old)? Also I would plan to retro-vent it somehow (I know its been done), replace the timing cover seals/gaskets while I'm in there.
2. Leave it alone and hope the rotor is OK and not about to grenade into a billion pieces at higher RPM's.
I think I should leave well enough alone but given how hard it is to find a QUALITY replacement Opti-Spark maybe a little preventative maintenance is a good thing? Thoughts? Opinions?
FYI, considering I just changed the coolant, the soonest I would do this is 2018 unless I have an issue. Which ever comes first.
you know my current (likely original) Opti-Spark is working 100%.
Given how I use the car (auto-x/track days) would you:
1.Pull the Opti-Spark to inspect bearing/replace cap and rotor/seals to ensure its life at higher RPM (assuming the unit is 23 years old)? Also I would plan to retro-vent it somehow (I know its been done), replace the timing cover seals/gaskets while I'm in there.
2. Leave it alone and hope the rotor is OK and not about to grenade into a billion pieces at higher RPM's.
I think I should leave well enough alone but given how hard it is to find a QUALITY replacement Opti-Spark maybe a little preventative maintenance is a good thing? Thoughts? Opinions?
FYI, considering I just changed the coolant, the soonest I would do this is 2018 unless I have an issue. Which ever comes first.
01-31-2016, 12:19 PM
#2
I would hold what you have.
You know the saying.
01-31-2016, 01:45 PM
#4
Race Director
should have known this thread would be a magnet that i cant not give my $.02...
is your car/street driven ?
if so, then yes do a pre-emptive take it apart, inspect, clean everything, install new cap/rotor, add custom vent harness. replace seals and seal up the halves with rtv silicone for good measure.
my 93's oem opti was done at 26k miles in 2001. seals had shrubk/cracked, water had got in and rusted it. and this was a garage queen car.
i pretty much guarantee your seals have shrunk/cracked - its a disaster should it get wet.
in my case it didnt just suddenly shut the car down/ tow home. it would start misifiring under a load.
now - if the only thing you do is dry autox and dry track events, its probably not so big a deal if the seals are cracked and you know not to wash the engine (as most of us here with lt1s do)
if you do go in there, be sure to do custom weep hole mod on water pump.
lastly (i write this not for you, but for the newbs who will read this)....that ac delco optispark with mitsubishi sensor is the best optispark ever made for that car. they are now unobtanium, so dont even think about buying a new 'china' optispark or rebuilt-in-china ac delco optispark. just clean it up, inspect, and vent and a new cap/rotor
again i know you are smarter than that
is your car/street driven ?
if so, then yes do a pre-emptive take it apart, inspect, clean everything, install new cap/rotor, add custom vent harness. replace seals and seal up the halves with rtv silicone for good measure.
my 93's oem opti was done at 26k miles in 2001. seals had shrubk/cracked, water had got in and rusted it. and this was a garage queen car.
i pretty much guarantee your seals have shrunk/cracked - its a disaster should it get wet.
in my case it didnt just suddenly shut the car down/ tow home. it would start misifiring under a load.
now - if the only thing you do is dry autox and dry track events, its probably not so big a deal if the seals are cracked and you know not to wash the engine (as most of us here with lt1s do)
if you do go in there, be sure to do custom weep hole mod on water pump.
lastly (i write this not for you, but for the newbs who will read this)....that ac delco optispark with mitsubishi sensor is the best optispark ever made for that car. they are now unobtanium, so dont even think about buying a new 'china' optispark or rebuilt-in-china ac delco optispark. just clean it up, inspect, and vent and a new cap/rotor
again i know you are smarter than that
Last edited by dizwiz24; 02-01-2016 at 07:48 PM.
01-31-2016, 06:05 PM
#5
Melting Slicks
Rubie
On my 1992 I was also chasing a similar symptom. I used a timing light on each wire and located misses. I first changed the wires. Same problem. Then changed the spark plugs-Fixed!
I am in the middle of changing my clutch assembly and flywheel. When completed I am going to flush the antifreeze and pull the opti and replace the cap, rotor, inspect it, and convert it to a vented system. The reason-Because the opti has been in there since 2004 and I am adding a MSD 6AL-2. Per MSD they recommend to have a vented cap (even on non opti's).
Good luck!
Steve
On my 1992 I was also chasing a similar symptom. I used a timing light on each wire and located misses. I first changed the wires. Same problem. Then changed the spark plugs-Fixed!
I am in the middle of changing my clutch assembly and flywheel. When completed I am going to flush the antifreeze and pull the opti and replace the cap, rotor, inspect it, and convert it to a vented system. The reason-Because the opti has been in there since 2004 and I am adding a MSD 6AL-2. Per MSD they recommend to have a vented cap (even on non opti's).
Good luck!
Steve
01-31-2016, 06:33 PM
#6
Race Director
Rubie
On my 1992 I was also chasing a similar symptom. I used a timing light on each wire and located misses. I first changed the wires. Same problem. Then changed the spark plugs-Fixed!
I am in the middle of changing my clutch assembly and flywheel. When completed I am going to flush the antifreeze and pull the opti and replace the cap, rotor, inspect it, and convert it to a vented system. The reason-Because the opti has been in there since 2004 and I am adding a MSD 6AL-2. Per MSD they recommend to have a vented cap (even on non opti's).
Good luck!
Steve
On my 1992 I was also chasing a similar symptom. I used a timing light on each wire and located misses. I first changed the wires. Same problem. Then changed the spark plugs-Fixed!
I am in the middle of changing my clutch assembly and flywheel. When completed I am going to flush the antifreeze and pull the opti and replace the cap, rotor, inspect it, and convert it to a vented system. The reason-Because the opti has been in there since 2004 and I am adding a MSD 6AL-2. Per MSD they recommend to have a vented cap (even on non opti's).
Good luck!
Steve
not saying this were your situation, but your post got me thinking about something....
chnging spark plugs, using dielectric grease and new wires might temporarily help out an ailing optispark by providing less resistance (and less chance of it shorting out internally).
that was my first step and it seemed to help out for a little bit.
however, then it did it acted up again at the dragstrip (after a couple passes when the motor was hot) and i 'knew' my problem was not plugs and wires.
the real problem was the optispark. in fact i didnt even know what an optispark was. a co-worker (who drove a 94 supra tt) told me about it and also about corvetteforum.com
btw. msd optisparks have given people all kinds of problems here. they are hit or miss.
i do agree with their advice to vent the optisparm
01-31-2016, 10:38 PM
#7
Melting Slicks
greetings and all due respect!!!
not saying this were your situation, but your post got me thinking about something....
chnging spark plugs, using dielectric grease and new wires might temporarily help out an ailing optispark by providing less resistance (and less chance of it shorting out internally).
that was my first step and it seemed to help out for a little bit.
however, then it did it acted up again at the dragstrip (after a couple passes when the motor was hot) and i 'knew' my problem was not plugs and wires.
the real problem was the optispark. in fact i didnt even know what an optispark was. a co-worker (who drove a 94 supra tt) told me about it and also about corvetteforum.com
btw. msd optisparks have given people all kinds of problems here. they are hit or miss.
i do agree with their advice to vent the optisparm
not saying this were your situation, but your post got me thinking about something....
chnging spark plugs, using dielectric grease and new wires might temporarily help out an ailing optispark by providing less resistance (and less chance of it shorting out internally).
that was my first step and it seemed to help out for a little bit.
however, then it did it acted up again at the dragstrip (after a couple passes when the motor was hot) and i 'knew' my problem was not plugs and wires.
the real problem was the optispark. in fact i didnt even know what an optispark was. a co-worker (who drove a 94 supra tt) told me about it and also about corvetteforum.com
btw. msd optisparks have given people all kinds of problems here. they are hit or miss.
i do agree with their advice to vent the optisparm
I will see how it all looks when I take it out.
Steve
01-31-2016, 11:00 PM
#8
if your going to play with it put some penatrating oil on your harmonic balancer then maybe loosen the bolts and start it a time or few.
02-01-2016, 05:34 PM
#9
Racer
Member Since: Aug 2015
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I Have 103K on my 94 and although I have no optispark issues I also want to change the cap and rotor. I am a little Leary about messing with it because I worry that after I get it all back together I will have problems with it.
I was also thinking that if I'm going to do it I might as well take it off and do all the re-sealing that people speak of and change out the water pump, idler pulley, belts etc.etc.
I was also thinking that if I'm going to do it I might as well take it off and do all the re-sealing that people speak of and change out the water pump, idler pulley, belts etc.etc.
Last edited by 94corvetteC4; 02-01-2016 at 05:37 PM.
02-02-2016, 07:50 PM
#10
Safety Car
Thread Starter
Given the cost of even a cheap cap and rotor (about $70 from Summit Racing) and a NEW Opti-Spark is $170 or so from Summit or Sea City or whatever......I think I'll leave well enough alone. The old saying DOES apply.
Even if I found some issue in the distributor (ie. worn bearings) I cannot rebuild that. No parts exist that I am aware of.
Even if I found some issue in the distributor (ie. worn bearings) I cannot rebuild that. No parts exist that I am aware of.
02-04-2016, 02:03 PM
#11
Instructor
Given the cost of even a cheap cap and rotor (about $70 from Summit Racing) and a NEW Opti-Spark is $170 or so from Summit or Sea City or whatever......I think I'll leave well enough alone. The old saying DOES apply.
Even if I found some issue in the distributor (ie. worn bearings) I cannot rebuild that. No parts exist that I am aware of.
Even if I found some issue in the distributor (ie. worn bearings) I cannot rebuild that. No parts exist that I am aware of.
Mine was bad enough that I went with the MSD unit. Scope patterns look normal and no problems so far.
02-04-2016, 04:28 PM
#12
Melting Slicks
If you saw this thread I posted https://www.corvetteforum.com/forums...e-pattern.html
you know my current (likely original) Opti-Spark is working 100%.
Given how I use the car (auto-x/track days) would you:
1.Pull the Opti-Spark to inspect bearing/replace cap and rotor/seals to ensure its life at higher RPM (assuming the unit is 23 years old)? Also I would plan to retro-vent it somehow (I know its been done), replace the timing cover seals/gaskets while I'm in there.
Thoughts? Opinions?
you know my current (likely original) Opti-Spark is working 100%.
Given how I use the car (auto-x/track days) would you:
1.Pull the Opti-Spark to inspect bearing/replace cap and rotor/seals to ensure its life at higher RPM (assuming the unit is 23 years old)? Also I would plan to retro-vent it somehow (I know its been done), replace the timing cover seals/gaskets while I'm in there.
Thoughts? Opinions?
02-04-2016, 06:02 PM
#13
Safety Car
Thread Starter
I think it would be best to take it apart, clean out the crud in it (there will be some), install the venting and seal it. Doing this is the easy part. Getting to it is the time consuming part.
Mine was bad enough that I went with the MSD unit. Scope patterns look normal and no problems so far.
Mine was bad enough that I went with the MSD unit. Scope patterns look normal and no problems so far.
