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The Cheap Opti Thread

40K views 188 replies 28 participants last post by  96 Black 
#1 ·
Hey all,

I know there have been many previous threads regarding the optispark in our cars, but I felt it would be beneficial to make a current thread detailing the situation.

It seems that the general consensus is that the AC Delco unit is the only real option. However, RockAuto is currently charging $375 for a reman AC Delco unit, and I know that many people (myself included) cannot drop this kind of money. For $375, you can literally buy a new (used) LT1.

I have heard great things about the Skip White units, and I placed an order with them several days ago. Just today, I received an email saying that they are completely out of stock, and that they are on back order from the manufacturer. As a result, they refunded my money. Subsequently, they have removed the LT1 distributor from their website.

My question is: what is my next best option? The optisparks sold by the parts stores (AutoZone, O'Reilly, Advance, etc.) seem to get horrible reviews. Even with a lifetime warranty, folks are recommending I stay away from these units. I am considering buying an opti from Summit, which seems to get good reviews.

What do you guys think?

Thanks,

Matt
 
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#2 ·
Discount opti's are a crapshoot at best. If you've got the time,and inclination to swap them more frequently,and/or at a moment's notice. You may be more willing to "roll the dice" than I am....
 
#3 ·
there is a rumor that Summit bought up all the "new" Delphi units and selling them under their name.

https://www.summitracing.com/parts/sum-850060

IDK,,,it was another thread on another forum that mentioned it

....and if true who knows if that inventory is still around in Summit stock

so if it has to be cheap....get the part store one, likely a Cardone. Rockauto may also have the "off brand" ones also. At that point its a crap shoot. Some have had them without issue...and others...well we know about that
 
#25 · (Edited)
there is a rumor that Summit bought up all the "new" Delphi units and selling them under their name.

https://www.summitracing.com/parts/sum-850060

IDK,,,it was another thread on another forum that mentioned it
...
I don't know BALLSS, - this review made me flinch as I've heard only AC Delcos have the translucent phenolic yellow cap - all other non-genuine supposedly opaque black.

850060

Summit Racing Verified Purchase SUM-850060
So far working good- the cap was back not golds
1 of 2 found this review helpful.
Was this review helpful? Yes | No

Although that could be another urban legend to be debunked down the road.

I did notice the cap (it is black) with the aftermarket opti I pulled after just 18 months used flimsy little flat aluminum strips, not the stouter round studs. It appeared to be a Spectra based on a decal on the unit.
 
#31 ·
Everybody's Ignoring You

sorry, not cheap, but a different source. No branding listed. Maybe someone on this forum has experience with these....?
Store | Petris Enterprises
The pics look all the world like a used unit (blemished base, pock-marked bushing) with a pretty red tune-up kit (either an ?MSD or even the one that's only $17 on E-bay lol), and a REALLY expensive looking vent filter.
 
#5 ·
Good catch there. lol They're obviously selling 'at cost' and getting all their profit reselling $5 Felpro timing cover gasket kits. ::rolleyes::

QUOTE Caddylack: My question is: what is my next best option?

Based solely on what I've learned combing this forum and innumerable valuable hints:
1-Rummage your parts pile for an oem unit if you ever pulled one for whatever reason (i.e. I did that at 100,XXX on my old FWB as reg. maint. when genuine replacements were easily available and cheap)
1a-Or hit a JY for one
2-Make sure you're comfortable with the bearing play if any, retain the Mitsubishi brand optical sensor used in the original optis (apparently recognized as the only dependable brand, and NLA retail)
3-Get a new cap and rotor parts kit ($70-100) Yellow translucent cap preferred over opaque black. I read one of the aftermarkets has been not so good on the tune-up parts (Accel? MSD? - not disparaging either name, just heads-up to search yourself)
4a-Blue locktite rotor and any other screws
4b-Clean everything bone dry
4c-Apply dielectric lube at all sealing surfaces
5-Check condition of vent harness / valve assembly
6-Reinstall everything

And open to critique. I'm rounding up parts now to redo mine real soon.
 
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#6 ·
I do actually have a 94 Fleetwood parts car with 95k original miles. The opti was perfect when it was parked, but that was 10 years ago. Also, from what I have read, the 92-94 unit is not interchangeable with the 95-97 unit without modding.
 
#9 ·
I know we should keep to topic IE Cheap Opti.

That said if you have more time than money more diagnostics may help.

A oscilloscope can be used to confirm the high and low res opti signals are good. This is useless for intermittent issues and hard to do if the fail is heat, RPM, or engine load triggered. There is a basic voltage meter test for this that will show the opti is not working at all.(no start/run)

The opti signal should also be compared to the ICM input. If any wire connections are bad the ICM may get a bad or missing signal from the PCM.

Is the ICM signal from the PCM matching the coil output? ICM, coil, wires, and plugs are cheaper than a opti.

Clean the optical sensor. If it can not see it's led at full brightness it will send out a bad signal. Contamination in the distributor cavity will cause misfires as will a bad distributor rotor or damaged distributor contacts.

All this is easy to say from behind the keyboard. It will take a fair bit of work to do.

I have never found another engine where the "distributor" price is so close to the cap and rotor cost.
 
#10 ·
Anybody ever try Sac City Corvettte?

LT1/SBC

They claim their Optis have a sensor that exceeds the Mitsu specs and is good for up to 8000 RPMs, almost sound too good to be true. They come with a 2 year warranty, I was tempted to try one.
 
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#23 ·
Anybody ever try Sac City Corvettte?

LT1/SBC

They claim their Optis have a sensor that exceeds the Mitsu specs and is good for up to 8000 RPMs, almost sound too good to be true. They come with a 2 year warranty, I was tempted to try one.
I ended up buying one of these from their supplier, AIP Electronics. They are $99 at aipelectronics.com. Their website talks about how other optis are made overseas, leading me to believe that theirs are not. I guess I will be the guinea pig. I have heard a mix of good and bad things about this opti. Seems to depend who you ask.
 
#11 ·
Several threads on forums on Opti woo's and many comments about the cheapo store brand (Cardone) ones either working great then failing quickly or not working at all

Sadly this 20+ year old GM SBC is fading in OEM part availability. IDK if the "reman" AC Delcos are good but have not read any negative 411 on them. The MSD Opti lately has had a significant issue from various threads I have read lately. Delphi "new" ones seem to be extinct.

Sooo short of getting lucky with a offshore brand My $.02 is keep or find original AC Delco for if anything to harvest the Mitsubishi sensor from and put it in a cheapo opti. Either right out of the box or keep it until the cheapo one fails. Not 100% fail....but seemingly a high % do.

I have successfully cleaned my AC Delco that had oil in it (WP drive seal leak) and replaced the C&R with the MSD and it has work flawlessly for years now.
 
#12 ·
Opti - related - Cracked #5 Cap Tip

I was wondering what you all might think of me trying to use super glue and some baking soda to "plastic weld" part of a cracked tip off of the #5 terminal? The piece that is cracked out is a "V" shaped chunk. No idea how it cracked. This cap was sitting on a shelf in my garage. I'm guessing that someone knocked it off the shelf or dropped something on it. I can't bring myself to throw it away but I don't want to put it on the car and have #5 come loose from vibration or heat.

Thoughts?
 
#13 ·
.......
Thoughts?
Yah. My thoughts are I done met a bloke more cheaper than I could ever aspire to be. ROTF Do you even have that cracked-off chunk anymore? Or are you going to 3D print the missing piece using just that baking soda and glue?

There is a VERY real possibility that you'll be installing a part starting off in worse shape than the original it's replacing. lol Considering it takes little more than a cross-eyed look or sneeze for Optis to underperform there's no way I'd consider the cost savings of a new cap as worth the potential diminished capability or probable repeat teardown soon after you're experiment.

If it's any consolation there was a time when I had zero $$$ I would have just filled the wire boot with silicone, jammed the wire in and tie-wrapped everything together. Now THAT'S cheap, and you're only out a #5 wire it it don't work.
 
#14 ·
if you showed a pic we could see what this "crack" is.....but from description you have a broken chunk on one of the plug stands....in my world that is a trash can distributor cap period.

if it's just to get the car on the road for no $ (meaning is it worth not buying a $50 cap) than glue/silicone away
 
#18 ·
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
What BALLSS said. I would be concerned that any repair other than temporary would lead to a possible carbon track. Then it's tear into it again.

Mark: Snowman-33
 
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#16 ·
I do have the "chunk". There are no "missing" pieces. I'll get a picture and attach it to the thread that I started on opti maintenance and replacement on july 18, 2017 in the engine problems folder. With all of the chatter about cheap optispark units, I'm confused about the suggestion that I buy a $20 cap from EBAY. Won't it be junk? A cap and rotor kit from Advance Auto is over $150.
 
#17 ·
Advanced sells the same cap and rotor as everyone else.
They just mark it up.
They are ALL made in China.

ALL NEW optis are made in China, even AC Delco.

I just put a White Performance opti on my new stroker motor
It will last as long as you take it apart, blue print it, and put loctite on the rotor screws!

An inexpensive cap and rotor is better than a broken one ;)

Nab
 
#22 ·
Well gentlemen, another one pulled back safely from the edge. ;)

Here is the photo...

....I guess that I could put a good cap on it and keep it as an emergency spare instead of throwing it away.
Wise choice.

Truth be told there was a time I'da repaired a crack like that on a cap just to prove I could like you. But that would've been 45 years ago on a beater with points distributor you can pop the cap with 2 clips in 5 seconds.
 
#28 ·
Unsure whether Delphi and AC Delco are the same company, or a past merger. I do hear years past Delphi as original part supplier for things on GM, just don't hear much talk of them surrounding Optis. It sounds from another recent thread you had poor fortune with yours with the cap.

lol In the old days a savvy mod would combine all the growing chatter on Opti proglems into one thread, 'ALL THE CRAP ABOUT CRAP OPTIS HERE OR ELSE!' lol
 
#34 ·
We'll see.
 
#36 ·
Installed and it fired up. Have to install WP when I get a day off. ugh
 
#37 ·
engine started good but you better check that you have NO CODES !!! last time I got screwed did not check for codes................ new opti defective ........

I did not just take this new opti out.. I also worked on it , to find that , it was not properly built ..some chinese child messed up on the fabrication ..
 
#39 ·
what I have found is the OEM yellow epoxy caps are able to handle the high voltage and heat ..these china black plastic caps get damaged due to the engine environment..

I ran a aftermarket opti for 3yrs then it began to create miss fires . worked good for 3 years BUT only 8K miles .. cap was distorted and had carbon tracks leaked air bad , seals destroyed . also this vehicle does not run in bad rainy weather ...

so now the 22 year old opti is in and working great... rotor has a slight wobble ..
 
#40 ·
Further to your point, the 1-yr old AfterMarket opti I removed showed evidence the cap had sucked in and severely scalped the rotor. I read at least once this can happen in connection with the vent line being blocked. The AM cap appeared visibly "less stout" and flimsy in mass with a thinner casting compared to the 'solid block of epoxy' yellow AC replacement cap.

I have a pic showing it I believe in the Opti Build thread.
 
#41 ·
I am sure many do not have the yellow OEM GM distributors... reason is the return of the old distributor core ....

so because I still have this original opti comparing these new opti ,, like you say , is easy to reveal this new opti problem. the high voltage runs in the cap with soft plastic is the problem.. your cap issue is strange to me because I did check out 3 opti NEW and they all leaked ,, poorly sealed ...compared with the 22 yr old opti no leaks ..cap distortions !!!

now reports MSD caps has poor quality .. years ago these had good reviews.
 
#42 ·
The AM unit I removed had one of its two silicone seal rings completely missing and a 1/2 teaspoon of oil inside, making me wonder how the "vacuum sucking the cap down" was possible at all. My experience has shown for any aftermarket part we have to rely solely on overseas to design and build, that they start off with way below market cheap pricing and absolute crap quality, and use early adopters as beta testing for imminent (but painful for customers) production improvement. Give it 4 years and the blogs get back to them and they'll eventually get all the bugs worked out.

Wait a minute, we'll all have 24x by then....
 
#46 ·
I just installed this Opti after my previous “GM05” Opti picked up a sporadic misfire due to oil contamination. https://www.amazon.com/Optispark-Di...pID=41qsutJu1UL&preST=_SY300_QL70_&dpSrc=srch

Took me about 4 hours to replace, and I’m confident I could do it in half the time next time. Aside from tearing the o rings on the shaft (I used the ones that came with the Felpro front cover gasket kit to replace them), the car fired up and ran well on the first attempt. Only have 100 miles on it, so no input on longevity.
 
#47 ·
Those o-rings included in the FelPro kit are intended for the water pump coupler,and not the optispark.... I sourced some appropriately sized opti o-rings made of Buna-N rubber that neither flatten out,or become brittle exposed to oil...
 
#48 ·
Yeah, I know, but they were smaller than what came on the replacement opti, which tore on installation, but slightly thicker than what was on the previous opti, which were allowing oil past them.

If it leaks more oil, I’ll pull the opti again and do something different with the o rings.
 
#49 ·
The "O" rings on opti are to stabilize/secure it inside the cam. Not to seal oil out of the opti. There is no oil coming from "inside" the cam

Oil gets into the opti from oil leaks above it (wp drive or intake) that migrates between cap & base of opti or on bearing/drive shaft where it meets the back of opti casting

Coolant enters same way if WP is pissing out its weep hole

Dialectic grease is your friend to cover the big O ring opti cap seal
 
#82 ·
I Use dielectric grease on ALL Points of the Distributor system. Opti , plug wires, coil wire AND especially Pass side Opti plug wire connections where they are in a position that will allow moisture to seep by because of the connections being at downward angle .
 
#51 · (Edited)
opti shaft O rings are different . they are able to handle gas/oil/high temps petroleum products .

on the water pump coupler that part I did do a few times , doing water pump the felpro kit O rings. that last pump I put on I used , silicone brake grease on that coupler and those O rings. so far this is the only water pump that has not weep when sitting or running . possible the pump weeps due to the coupler binding and causing the wp seal to unseat or wear ..

one forum member stated the gaskets do effect how the coupler sets on the pump drive shaft .
so with no gasket it could push on that shaft too much. I use permatex formagasket on those WP coolant gaskets and no leaks .. also on one of the WP mounting bolts I apply some sealant on the threads the one the passes into the coolant system. only very small amounts like paint..

silicone sealer takes 24 hrs to cure what I use just about 1 hr.. stays pliable ..
 
#52 · (Edited)
This is what I found when I pulled my GM05 Opti that had developed an occasional misfire. The water pump drive shaft seal, which I had replaced this summer, is not leaking, nor is the intake manifold. The oil appears to be coming from the hole in the center. (I did replace the Opti seal at the same time that I replaced the water pump seal.)





These are the o-rings that were on the GM05 Opti. They seem pretty thin, and I suspect they were not thick enough to prevent oil from weeping out the hole. You can't really tell in this pic, but the part of the Opti that goes up against the seal was pretty burnished.



This is what size of o-ring that was on the new AIP Opti, which I ended up tearing when inserting the shaft into the cam hole. The water pump o rings, which I didn't take a picture of, where of a slightly smaller diameter, and I am reasonably confident that I got them inserted into the cam hole without them being torn.

 
#153 · (Edited)
This is what I found when I pulled my GM05 Opti that had developed an occasional misfire. The water pump drive shaft seal, which I had replaced this summer, is not leaking, nor is the intake manifold. The oil appears to be coming from the hole in the center. (I did replace the Opti seal at the same time that I replaced the water pump seal.)

...

These are the o-rings that were on the GM05 Opti. They seem pretty thin, and I suspect they were not thick enough to prevent oil from weeping out the hole. You can't really tell in this pic, but the part of the Opti that goes up against the seal was pretty burnished.



This is what size of o-ring that was on the new AIP Opti, which I ended up tearing when inserting the shaft into the cam hole. The water pump o rings, which I didn't take a picture of, where of a slightly smaller diameter, and I am reasonably confident that I got them inserted into the cam hole without them being torn.

Haven't been on in some time. I like to revisit things to see if parts actually last. Or don't. And document it.

I upgraded to Viton O-rings 5 years ago. Finally pulled my opti for the first time since the engine swap 5 years back. This is what I found:



and



Shared the first because as you can see, the GM05 used the same Viton rings. Apparently, they do hold up after all these miles and years. Not even going to replace them. They're fine.

The second pic just confirmed my suspicion about using Si hose where there's oil. The hose is intact, but there's a 100% difference between the area adjacent to the opti housing and the air filter end. The former is hard as a rock. The latter still feels virtually brand new.

HTH. Carry on...
 
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