Randy_in_MD

Can someone please try convince me that the extra hp of the 92-96 LT1 is worth the gamble of potential optispark issues that could be avoided with the L-98. (Also the high third brake light position).

I have had a 1992 and two 1996 Corvettes. They were all daily drivers and not babied. To be honest, I had never heard of the optispark or any of the related issues until I joined this forum a few months ago.

I feel like the looming specter of the OPTISPARK is severely limiting my choices.

TorchTarga94

Sounds like you answered your question. Find a well maintained 95'/96' with the original opti and motor on.

CA1992C4

That's a lot of horsepower to give up. My 1992 just had the optispark replaced after 24 years, so I should be good to go for a long time.

TorchTarga94

Knock on wood brother

RIC96

I'm still running my original opti and I've had a water pump implode.

MRPVette

I originally wanted an L98 when I started reading about this whole opti issue but I found a 95 I couldn't pass up, the whole opti thing sounds much worse than it is I eventually ran into the dreaded opti problem with mine about 2 1/2 years in but replaced the opti and water pump on a Saturday for about $500 with No problems.Anyway I couldn't imagine have less the 300HP now.

sluggballz

I had a heater hose pop and empty all over my original opti on my 95 four years ago. I sputtered home as I was less than a mile away, it bucked and kicked a bit but made it. I removed the opti disassembled and cleaned everything, put a new cap on it that carried a lifetime warranty and have been going strong ever since.
Stuff happens, the world is an imperfect place, but don't let the THOUGHT of something that may or may not go wrong deter you from being happy.

Renfield

Being that I am down to the #@&%# Harmonic Balancer on our '95 after having bled all over my '96 for a month, I would run, don't walk from the optispark.

My choice in hindsight would've been the '91 with no hideous high mount afterthought brake light and last of the L98s. Though the OBDII system is helpful, it's not worth the opti-pain IMO.

Yea, you might get an original but you can't service the bearing. Or you might get a chinese turd. You can spend hundreds on a Petris and have the same chance as a $99 AIP unit. Either way, getting that sucker out and replaced is no small achievement.

I've read of those who brag of being able to replace the opti in an hour, including radiator drain. Well maybe, in a well equipped shop if you've done them daily for a month. Otherwise, ahem, in a pigs eye.

Silver96ce

I had to change the opti twice on mine and when I did a cam change, I had to remove it a third time. The 1st time was a pain but the 2nd and 3rd were much easier since I already knew what to expect (and do) plus I put anti-seize on the back the balancer pulley.

If you haven't gotten the balancer pulley off yet, make sure to soak the bolt holes with penetrating fluid for a couple of days before trying. It can be a real pain. When you put it back on, put anti-seize on the back in case it has to be removed in the future - makes it very easy. And put blue locktite on the rotor screws to help keep them from vibrating out - a cause of many opti failures it seems.

As for the opti issues, I didn't let it scare me off even though I knew about the potential for it before I bought the '96. I'll take the extra horsepower, OBDII and R134a refrigerant over the potential opti problems.

chatham

changing an opti is no worse than changing a water pump. it's easy peasy and about as basic as you can get. if you cant do that then i'm not sure I would be buying a 32 to 21 year old car unless you got deep pockets to pay someone else.

but back to your point of, is the opti a problem I should worry about, mostly no but sometimes yes. kind of like, should I get married cos there is so much divorce?

SJW

The biggest problem associated with the opti is that reliable replacements seem to be a hit-or-miss proposition these days.

Yes, it's unfortunate that the opti was placed ahead of the camshaft, leaving it vulnerable to a coolant douche if the pump or a hose lets go. And, yes, it's a nuisance job to replace it. But, it's just a bunch of bolts, only a step farther than the water pump. As others have noted, the most difficult part of the job often turns out to be getting the harmonic damper to pop free of the crankshaft hub. A good soaking in advance with a top-quality penetrant can really help. And a film of anti-sieze applied to the damper-to-hub mating surfaces (especially the inner bore of the damper) can go a long way toward making subsequent opti replacements much easier, as it'll prevent the damper from rusting to the hub and seizing in place. And it's always easier doing a job that you've already done at least once before. Experience is a huge help.

I would not for a moment hesitate to buy an LT1 or LT4 Corvette, out of fear of the opti. All cars have their design deficiencies, it's just a matter of which poison you choose to ingest. The earlier C4s have their issues, too. As do the C5s. And C6s. And C7s. And, most certainly, also the C1 thru C3. If you wait until a perfect Corvette appears, you'll never own one.

Live well,

SJW

Patsgarage

What do you want the car for ? If it is just a driver than the L98 has more than enough power for 99% of what you will do on the street. If you want a track/drag car than the extra power of the LT1 is the way to go. It also depends on if you can replace a failed opti yourself, rather than paying shop time.

mtwoolford

Let me preface every thing I'm about to say with the fact I own a 96 LT4.

It ain't just the opti; there's a whole host of other LT specific items: the double or triple cost of the water pump, and what they don't tell you, or forget to mention, the water pump drive is supported by a bearing assembly in the block itself which of course is another LT specific item; and then there was the genius who decided to make the oil pump drive housing out of plastic and then bury the whole damn thing in the lifter valley...then there's the timing chain and sprockets, again an LT specific item;

the LT timing chain cover Has 3, not 1, oil seals in it so the possibility of an oil leak has gone up by a factor of three...and reference the above mentioned water pump support bearing in the block, once it gets loose, the coupler between it and the water pump starts to have radial play, THEN the oil seal begins to leak and you can replace that seal till the cows come home but it will still leak until the bearing is replaced.

Optiis? late (95 and 96) optiis are a very robust unit and on mine the vent system worked very well until the hoses ("harness" in opti speak) went south, one got cut by the serpentine belt, the other eventually failed from heat and being soaked with oil (see note above about timing chain cover seals) and that pretty much eliminated the "vented" portion of that particular opti.

Coupled with a short 5 year production run, LT engines are not for the faint of heart...not that the LT engine is inherently bad..it's not, it's a very powerful sophisticated engine...but it's like any machine, once the parts pipeline starts to dry up maintenance becomes more difficult and more expensive, or as a wise man (me) once said, "it ain't whether or not the part is expensive, its whether or not its available at any price" .

The aftermarket never stepped up and produced new LT blocks, which is a shame; new engine blocks for earlier engines are still being produced.

Where LT engines shine is the better heads (again an LT specific item), intake manifold and access to the fuel injectors....hey they're right there, out in the open!

All the previously noted LT specific items notwithstanding, one great fact about LT engines, or any generation one small block is that the rest of the engine parts all interchange and we ain't gonna run out of small block chevy parts anytime soon, if ever.

The LT engine did come from the factory with more horsepower than the L98, and in the case of an LT4, considerably more...but you've got to ask yourself, in a twenty (or thirty?) year old car and in an age of bone stock cars putting out in excess of 400 horsepower, are those small horsepower gains really that important? quick answer: well of course they are . Or more to the point, is the added power of an LT over an L98 worth the extra cost , extra headaches?

That my friend, is a question only you can answer.

SmokinBlack

I currently have an absolutely mint unmolested '87. I've had it for years with very few issues. However, try finding original size tires locally for the thing or even correct spec aftermarket wheels without breaking the bank. Even other parts seem to be very difficult. I recently had to try and find an ABS relay for it. Again, much more difficult than you would think.

This brings us back to say what has been said thousands of times on this forum over the years. Buy the best condition Corvette that your budget allows, independent of years. They all have their positives and negatives. But the one thing that has held true over the years is that condition means everything in the long run.

Renfield

You're probably right. I likely have no business turning a wrench. But in my experience, neither do most so-called mechanics.

Still, I have been doing just that for over 40 years. From the PS pump on my '64 t-bird right up to the head gaskets on my '83 F100.

I've pulled the Opti out of my '96 twice and onto my third in the '95 and it never stops sucking. But getting the balancer off is the highlight. Honestly, I would prefer to stare down the pistons in my Ford again than deal with this #^&%* Opti.

Part of the pain is the list of "while you're in there" projects.

Then there is the waiting period for regaining trust in your vehicle.

RichS

Sometimes I think the opti gets replaced a lot when not bad and it's something else. Sometimes you see a post about the seat cushion having a tear and someone blames the opti.

QCVette

I have had 8 LT1/LT4 cars and never had an opti problem. Some of them had high mileage too, and a couple had a water pump fail and dumping on the opti.

My opinion is that it is still fairly reliable and most don't fail. The ones that do fail we hear about. But to me it is just a distributor, if it fails then fix it. Granted it is harder to do than other small blocks, but it is still just a distributor.

For me, I like the LT1/LT4 better than the L98. I like the extra power. My current LT1 and LT4 get better mileage than my L98 did too (some of that may be due to 6 speed transmission though), and the torque curve is almost flat so it is easy to drive on the street. Even if you do not have it in the optimal rpm range it still pulls good. My LT1 could pull 5th gear from about 25 mph to over 150 (never tried higher).

FASTAZU

I like the look of the L98, The power of the LT1/4. Not a big fan of the opti but it is what it is and would not pass on a nice 92 up based on it as I like the interior of the later C4's better. As to the third brake light I prefer the high mounted,.

You could just add a ZR-1 to your list and get the best of all, more power, no opti, looks great.

Kevova

I'm not a fan of the Opti spark. You have had good luck with 3 cars, that by itself should install some confidence in the LT1. The forums as a rule have more threads about broken stuff than how great something is. I really wouldn't fret about it, the 95-96 cars were the best built of the C4s.

Renfield

You mean the halo wart? To each.

Besides having had their effectiveness mired in questionable stats, I am not a fan of this Reagan era mandate. And as implemented by Chevrolet, the early version remains a styling disaster to my eye.

If noting else it is certainly not faithful to the original C4 design. Just a mandate dutifully fulfilled. I would still buy an 86-90 because the replacement hinge from an '85 would cure it.