^^ The official optispark preservation thread ^^
Le Mans Master
Joined: Oct 2008
Posts: 9,758
Likes: 49
From: Houston Texas
not to thread hijack, but we all should be figuring out how to make our LTx cars compete and beat the latest LSx motors.
Im tired of reading threads, in the c4 section, of 'how do I change my spark plugs'
If you go to the C5 section, you will instead see posts of 'how do I shut down liter streetbikes'.
As for the optispark, seal it up w/ RTV silicone, dont buy the MSD-replacement optispark, add a vent cap & system (if 92, 93, 94), new non-MSD wires, and dont worry about it....
Worry about shutting down the newer model corvettes. They are your biggest threats on the road.
Im tired of reading threads, in the c4 section, of 'how do I change my spark plugs'
If you go to the C5 section, you will instead see posts of 'how do I shut down liter streetbikes'.
As for the optispark, seal it up w/ RTV silicone, dont buy the MSD-replacement optispark, add a vent cap & system (if 92, 93, 94), new non-MSD wires, and dont worry about it....
Worry about shutting down the newer model corvettes. They are your biggest threats on the road.
"Don't worry about keeping your car running" because some how a non running car will beat a LSX.. 
The only threat on my road is road racers like you.
Le Mans Master
Joined: Oct 2008
Posts: 9,758
Likes: 49
From: Houston Texas
That is a very good idea and not hard to do. The weap hole could be tapped threaded. Insert a nipple on it with a hose and go.
Heel & Toe
Joined: Oct 2010
Posts: 15
Likes: 0
From: Campbell California
Thanks woolford and ch@0s for you responces. I promise I will never ask anyone how to change my spark plugs. This Corvette #4 for me over the last 40 years. I know that compared to others thats not a lot, but I love them all the same. It seems to me, in reading post after post about the opti, that the main cause of failure is the water pump leaking coolant into it. In LT1*C4 fantastic article on the R&R of the opti, he decided to try converting his water pump to electric for cooling reasons. Is`nt one of the main causes of pump failure the shaft seal? which is why the weep hole exists to begin with so you know the seal has gone bad. One of the big benefits of the electric conversion as far as an opti equipted car is concerned, is that now there is no more shaft seal. Just install the plug that comes with the kit and plug the now needless weep hole and be done with it! Thanks for the comments about the MSD unit,as it was on my mind to go that route. Its amazing that the Mack Daddy of ignition companies would make parts that don`t last.
Team Owner
Joined: Oct 2000
Posts: 96,443
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From: Fort Knox, KY
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Those pieces of platinum can be bad for your cylinder walls and other engine internals, though.
Racer
Joined: Nov 2002
Posts: 420
Likes: 0
From: palm harbor fl
i have had good and bad to say about the opti.
first the opti on my 97 t/a was still working after 107,000 miles when i changed it and the waterpump for maintainance reasons,car started the same and ran the same no difference.
my vette a 94 was converted to a 95 opti when the heads and cam were done,that opti lasted about 5,000 miles before it wouldn't go more than 1/2 throttle without breaking up.The rotor was chewed up and shot from brand new.
so i'm on the fence with this distrubutor,never had the waterpump leak on it ,it lasts as long as the opti itself.
one thing I believe is buy g.m. opti only,don't buy msd piece of junk!
first the opti on my 97 t/a was still working after 107,000 miles when i changed it and the waterpump for maintainance reasons,car started the same and ran the same no difference.
my vette a 94 was converted to a 95 opti when the heads and cam were done,that opti lasted about 5,000 miles before it wouldn't go more than 1/2 throttle without breaking up.The rotor was chewed up and shot from brand new.
so i'm on the fence with this distrubutor,never had the waterpump leak on it ,it lasts as long as the opti itself.
one thing I believe is buy g.m. opti only,don't buy msd piece of junk!
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Heel & Toe
Joined: Oct 2010
Posts: 15
Likes: 0
From: Campbell California
CMS , would it be advantageous to just throw in the towel and install the LS1 style coil over system instead of possibly reserving yourself to a life time of optispark issues? Also, is there a decent tool for the home garage mechanic for down loading codes and doing basic diagnostics for these cars? One issue I have with my car is that it has a Procharger supercharger on it. I have no literature that no doubt came with it when it was new. I don`t have any tuning information, nothing. Since the misfiring, rough idle condition starting, it has not changed. It actually sounds like it is OK when its cold. But after a couple of minutes idling in the driveway, it starts acting up. Out on the road it misfires and will not allow me to give it heavy throttle input without misfiring. The temps and pressures are fine, no wild swings in any of them. Out on the road, the water temp never goes above 185.
Melting Slicks
Joined: Jan 2009
Posts: 3,482
Likes: 196
From: folsom california
the above sticky "C4 Technical Summary & FAQ" offers some good insight to opti's and the reasons for their failure: water, carbon tracking in the cap (moisture related) and bearing failure causing misalignment of the optics. its well worth a read.
Pro
Joined: Dec 2009
Posts: 502
Likes: 0
I have posted this a LOT, but the opti will last a long time and you can wash the engine bay. I live in FL and my 93 is a DD, it has gone through 7-8 inches of water with zero problems.
Do these simple steps:
1) seal the opti with sealant when installing
2) Seal a 12-14" vacuum line to the weephole and route hose past opti
3) Put vacuum to opti, either get vented cap or install your own.
My car has 190k miles and has had 3 opti's and one I dropped the WP to take it out.
One reason the opti has a bad rep is people trash it for no good reason, guess it was like the 3k mile oil change. Till oil change companies started advertising it, nobody did it and now the opti gets blamed for everything because people trash it without and reason.
I have seen atleast a dozen posts where the OP will throw parts and they will say the opti was bad without any checking first. Guess that is why there has been so many opti's in the 'Parts for sale' section.
Do these simple steps:
1) seal the opti with sealant when installing
2) Seal a 12-14" vacuum line to the weephole and route hose past opti
3) Put vacuum to opti, either get vented cap or install your own.
My car has 190k miles and has had 3 opti's and one I dropped the WP to take it out.
One reason the opti has a bad rep is people trash it for no good reason, guess it was like the 3k mile oil change. Till oil change companies started advertising it, nobody did it and now the opti gets blamed for everything because people trash it without and reason.
I have seen atleast a dozen posts where the OP will throw parts and they will say the opti was bad without any checking first. Guess that is why there has been so many opti's in the 'Parts for sale' section.
Heel & Toe
Joined: Oct 2010
Posts: 15
Likes: 0
From: Campbell California
Well I certainly have a wealth of knowledge available to me on this forum. I guess I will support CMS and purchase one of their Lifetime warranty units. I also think I will go ahead and convert the water pump to electric and eliminate the coolant leak issue, at least somewhat. Plus the advantage of the extra cooling ability in low rpm situations(traffic) should be of good benefit. The procharger sounds like its got a bearing going out, so I`ll get a hold of them while I have the car apart. I downloaded LT1*C4`s article on the R&R of the opti and the conversion of his water pump to electric, so that should help out a lot. I`m actually looking forward to doing the work. I`m hoping to get my youngest son involved for a little father son time. He is a trained BMW mechanic, so I hope he won`t be offended by working on a Corvette. I`ll have to promise not tell his friends.......
Heel & Toe
Joined: Oct 2010
Posts: 15
Likes: 0
From: Campbell California
Well, I took the opti off and got inside. Its completely burned off five of the eight cylinder pickups in the cap, actually removed bits of plastic from the cap. The rotor is burned and carboned up as well, but it still spins free! It had a little moisture in it, and it appears the vacuum hook up was used for something else on one of the hoses as it was not connected to anything. Still had the serrated hose fitting in it, going nowhere. I`m guessing the shop that installed the Procharger used it for something they needed.
Pro
Joined: Jun 2008
Posts: 610
Likes: 1
my 96 opti has proven very reliable, I think the original would have gone on, limited by the condition of the cap and rotor of course, for almost forever had the vacumn vent harness not failed; the small hose from the rubber intake coupler was cut by the serpentine belt and the larger hose from the opti to the intake manifold was completely rotted through from heat and being oil soaked.
with the cap sealed with rtv and the vacumn vent system intact and working properly, I would not be concerned driving it in any weather that I would otherwise consider safe to drive in. Of course there's a point when driving any car makes no sense; you just reach that point a little sooner in a vette.
of course, GM could have kept the distributor on top of the engine where its accessible. but they didn't.
with the cap sealed with rtv and the vacumn vent system intact and working properly, I would not be concerned driving it in any weather that I would otherwise consider safe to drive in. Of course there's a point when driving any car makes no sense; you just reach that point a little sooner in a vette.
of course, GM could have kept the distributor on top of the engine where its accessible. but they didn't.
The 96 with it's vented system is impervious to water intrusion. I pressure wash the entire engine bay with zero ill effects. As you say, it is essential that the vacuum hoses are in good condition. One of mine got cut the same way yours did, and I found it - after washing the engine! A half hour ride and a new piece of hose fixed it nicely.
Regarding wet weather driving, I found the factory Goodyears to be very poor in the rain. I have a set of cheapo Kumhos on there now which have massive water channels and the wet grip is amazing.
Race Director
Joined: Sep 2001
Posts: 14,668
Likes: 749
From: NEwhere Ohio
Happy with my optispark.
There is nothing wrong with the optispark. just a bad rap for no reason.
Also, the talk about replacing the WP - as a preventative measure is not necessarily good advice.
Where a 'new' WP rebuilt at thesedays? Does anyone know?
Thats like saying you should replace your OEM alternator as preventative maintenance.
it sounds like a good idea, but all the replacement rebuilt OEM alternators are rebuilt in mexico / china.
You are betting off finding a junkyard car, with used OEM parts, than buying the latest and greatest rebuilt/remanufactured parts from mexico/ china.
My .02
Also, the talk about replacing the WP - as a preventative measure is not necessarily good advice.
Where a 'new' WP rebuilt at thesedays? Does anyone know?
Thats like saying you should replace your OEM alternator as preventative maintenance.
it sounds like a good idea, but all the replacement rebuilt OEM alternators are rebuilt in mexico / china.
You are betting off finding a junkyard car, with used OEM parts, than buying the latest and greatest rebuilt/remanufactured parts from mexico/ china.
My .02
Le Mans Master
Joined: Oct 2008
Posts: 9,758
Likes: 49
From: Houston Texas
There is nothing wrong with the optispark. just a bad rap for no reason.
Also, the talk about replacing the WP - as a preventative measure is not necessarily good advice.
Where a 'new' WP rebuilt at thesedays? Does anyone know?
Thats like saying you should replace your OEM alternator as preventative maintenance.
it sounds like a good idea, but all the replacement rebuilt OEM alternators are rebuilt in mexico / china.
You are betting off finding a junkyard car, with used OEM parts, than buying the latest and greatest rebuilt/remanufactured parts from mexico/ china.
My .02
Also, the talk about replacing the WP - as a preventative measure is not necessarily good advice.
Where a 'new' WP rebuilt at thesedays? Does anyone know?
Thats like saying you should replace your OEM alternator as preventative maintenance.
it sounds like a good idea, but all the replacement rebuilt OEM alternators are rebuilt in mexico / china.
You are betting off finding a junkyard car, with used OEM parts, than buying the latest and greatest rebuilt/remanufactured parts from mexico/ china.
My .02
Le Mans Master
Joined: Jul 2009
Posts: 6,381
Likes: 66
From: SF bay area C.A.
C4 of the Year Finalist
There is nothing wrong with the optispark. just a bad rap for no reason.
Also, the talk about replacing the WP - as a preventative measure is not necessarily good advice.
Where a 'new' WP rebuilt at thesedays? Does anyone know?
Thats like saying you should replace your OEM alternator as preventative maintenance.
it sounds like a good idea, but all the replacement rebuilt OEM alternators are rebuilt in mexico / china.
You are betting off finding a junkyard car, with used OEM parts, than buying the latest and greatest rebuilt/remanufactured parts from mexico/ china.
My .02
Also, the talk about replacing the WP - as a preventative measure is not necessarily good advice.
Where a 'new' WP rebuilt at thesedays? Does anyone know?
Thats like saying you should replace your OEM alternator as preventative maintenance.
it sounds like a good idea, but all the replacement rebuilt OEM alternators are rebuilt in mexico / china.
You are betting off finding a junkyard car, with used OEM parts, than buying the latest and greatest rebuilt/remanufactured parts from mexico/ china.
My .02
totally, if it's not broke, don't fix it. Have gotten bad water pumps many times for some of my cars. To change one just because of it's age is crazy. The opti scare, is just that, like any other car, parts wear out some faster than others. I have found that the orginal parts seem to last the longest. You keep any car long enough you will be replacing the dist.
Last edited by kimmer; Nov 12, 2010 at 02:50 PM.
Race Director
Joined: Sep 2001
Posts: 14,668
Likes: 749
From: NEwhere Ohio
totally, if it's not broke, don't fix it. Have gotten bad water pumps many times for some of my cars. To change one just because of it's age is crazy. The opti scare, is just that, like any other car, parts wear out some faster than others. I have found that the orginal parts seem to last the longest. You keep any car long enough you will be replacing the dist.id feel terrible for someone who replaced their optispark cap/rotor with an MSD optispark cap/rotor as preventative maintenance and then had a failure as a result. Those things have shown themselves to be garbage.
i do think mod'ding an early model optispark with a late model vented cap and air inlet is a great idea. Use that vent in the cap as the air inlet (be sure to have a little air cleaner (a fuel filter will work) on the other inlet side).
You can then use one of the 3 optispark holes (enlarge with drill bit if you need to) and hook a vacuum up to that. Be sure to block off the other 2 holes. Make sure the vacuum source line is small diameter though. Dont want it too big.
Seal the whole thing up with RTV - even around the electric harness connector at the top.
The optispark will light the spark fine, up to much higher RPM's than a stock LT1/4 sees even.
Last edited by dizwiz24; Nov 12, 2010 at 04:52 PM.
Thread Starter
Former Vendor
Joined: Oct 2006
Posts: 134
Likes: 0
From: Waukesha Wisconsin
totally, if it's not broke, don't fix it. Have gotten bad water pumps many times for some of my cars. To change one just because of it's age is crazy. The opti scare, is just that, like any other car, parts wear out some faster than others. I have found that the orginal parts seem to last the longest. You keep any car long enough you will be replacing the dist.