Hey guys, I just bought a new opti and its coming in the mail this week. I was wondering though, most of the other posts about replacing the opti, people are saying to replace the water pump as well. I just had a new water pump installed less than a year ago when I had my motor rebuilt. Should I replace it again?

Also, any diagrams or specific instructions on how to change the opti and all that jazz would be very helpful. Thanks guys!!

Matt

 

if you havent really put alot of miles on it and it was new not rebuilt then you can reuse it,be sure to change the wires ,timing cover seals and idler pulleys if you havent already done so.

 

If the pump was a new OEM unit, it should be fine.

I'd STRONGLY encourage you to NOT install another OEM Opti in your '94. The '94 used the deficient first-generation Opti, and a replacement unit will be as deficient as the one you're removing.

Consider the DynaSpark as an aftermarket solution that should serve you much better than the OEM replacement. Alternatively, MSD has a new-to-the-market Opti replacement that looks good, but lacks the time-in-the-field record that the Dyna has established.

Definitely replace the plug wires, serpentine belt, and all hoses while you're in there, unless they're fresh.

If you have a good set of general mechanic's tools, and decent mechanical skills, you can tackle the Opti swap yourself. No special tools are required. Here are a few tech tips I wrote up some time ago about doing an Opti swap:

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Get a Factory Service Manual, and follow the procedure it lays out.

A few tips (I'm going from memory here, so I'll probably forget a few things):

Drain the cooling system.

Disconnect the MAF sensor and IAT sensor and remove the air intake duct with the MAF and IAT as an assembly.

Disconnect the ECT sensor and remove it from the water pump.

Remove the serpentine belt and tensioner.

You may find that you’ll need to unbolt the coil/ICM bracket from the front of the right cylinder head. I can’t recall for sure whether or not I did.

Unbolt (but don't remove) the power steering pump. This will help you to sneak the new plug wires in/out behind the pump, but may also be somewhat helpful when working on the water pump/Opti.

If you want more room to work, you can remove the radiator, but it isn't strictly necessary, and it involves considerably more work to remove it (I left mine in place).

The FSM will tell you that you need a special Kent-Moore puller to remove the crank pulley/damper. You don't. Here's how to get it off:

1. Raise the front of the vehicle enough that you can get under the car (it's also helpful to have it at a more comfortable height while you're working from above).

2. Remove the three bolts that secure the pulley/damper to the hub.

3. Mark the damper and hub so that you can easily see how to realign them to each other later.

4. Slide under the car with a long pry bar or hardwood dowel (I use a jumbo Snap-On screwdriver that's around two feet long) and a mallet.

5. Place the tip of the pry bar against the rear face of the damper, as close to the hub as possible (Ideally rest the tip alongside of the hub).

6 Give the pry bar a few whacks with the mallet, and with any luck the damper will pop off without too much of a fight.

You may find it helpful to apply a few whacks, then rotate the crankshaft in 120* increments, whacking it a few times at each interval (I haven't needed to do this).

It's also helpful to, if possible, shoot a bit of penetrating oil where the damper meets the hub, a day or more in advance of doing the job.

After you get the damper off, clean the damper/hub mating surfaces to remove all corrosion, etc, and apply a very thin coating of anti-sieze compound to these surfaces before you reassmble the damper to the hub. This should make it a lot easier to get the damper off next time.

Once the damper is removed, rotate the crankshaft so that one wing of the damper hub is at the six-o'clock position. This will position the other two wings at around the ten- and two-o'clock positions. In this orientation, the Opti will clear the hub as it is being removed/installed.

The Opti basically unbolts and pulls off as you'd expect, once you have the water pump and damper out of the way.

Once the Opti is out of the way, inspect the shaft seals for the Opti, water pump, and crankshaft. If they show any signs of leakage, replace them now.

When you install the new Opti, be sure to align it correctly with the cam gear, and don't force it into place against the timing cover (do NOT use the bolts to draw it into place). At most, give it a gentle bump with the heel of your hand to encourage it to pop into place.

Reassemble everything else.

Follow the cooling system refill procedure in the FSM carefully, and you'll have no problems with this. In particular, be sure to bleed the air out of the system as it's being refilled.

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Be well,

SJW

 

Thanks A LOT for your help guys! I had already purchased the unit and it is being shipped to me already, so its kinda too late to change my mind... I dont know if this changes anything, but I went on summit and there were two different ones that I couldve purchased that were GMPP. I went with the cheaper one, not because it was cheaper, but because the more expensive one said it was for 1992-1994 models and the cheaper one was for 1994-1996 models. I figured the one for the later models would be better because Chevy shouldve made it better not worse right? This is the link to the one I bought http://store.summitracing.com/partde...5&autoview=sku

If anyone has a second, can you check it out and tell me how much I messed up by buying that one? Lol. Thanks again!!

Matt

 

I think the better (later design for 95-96) ones were cheaper but will not fit your 94. You may have ordered the wrong one. THe Dyna and MSD are set up to add venting. Main problem of the earlier ones is no venting of the Opti. If you are going to do all the work to replace that Opti I'd get the best one out there, either the MSD or Dyna (IMHO).

 

Hmmm... That really would suck if I ordered the wrong one. I looked on the site though and it said that the later model one fits the 1994-1996 year models. Now, summit has definately been known to make mistakes before, but this would definately take the cake in my opinion. I guess I will have to see when I get it. Thanks!

Matt

 

Okay, there's your way out of this one. If they told you that a Gen2 Opti will fit your '94, they told you wrong. Tell them that you want to return it for a refund because it doesn't fit. Then get a DynaSpark or MSD unit instead.

The Gen2 Opti was used on '95 and '96 Corvettes. The Gen1 Opti was used on '92 - '94 Corvettes. You cannot bolt a Gen2 unit on a Gen1 LT1 without changing the camshaft, timing cover, etc. It simply won't fit.

Be well,

SJW

 

Summit messed up. I checked your link and it says 94-96, but it will not fit a 94.

 

Dammit... ok, Thanks guys, I will give them a ring a little later. I was just trying not to spend $500 on an opti. I guess theres no real way around that now. If I am going to spend 400 on a OEM, might as well spend the extra 100 and get the MSD. Thanks again.

Matt

 

Well, I just talked to the idiots at Summit and I guess I will be waiting until next weekend to do my opti-swap. I have to wait until Wednesday to get the opti that they sent me, then I have to spend MMMMYYYYY money to send back a part that they messed up and said would fit my car. Then, when they get it back, they will send me the right one, but since it is BUSINESS days, I wont get it until Tuesday or Wednesday at the earliest, putting a major botch in my plans because I have THIS Friday off to work on it. I absolutely HATE stupid people. I would just order the new part and wait for the refund until they get the other one, but then I would have spent $825 on the damn thing and it wouldnt leave me too much "fluff" in my bank account. Thanks for everyones help though!

Matt

 

I'd definitely spring the extra $ for either the MSD or the Dyna. You'll be far better off than with a replacement OEM Gen1 Opti.

And, I'd think that if you lean on Summit, they oughta agree to pay the return freight charges for this screw-up, because it was their screw-up. This isn't defective merchandise that they simply passed through from their supplier (something which wouldn't have been their fault), but was instead an error in their catalog. Will they not ship an MSD unit to you in advance of receiving the wrong part so that you can maintain the schedule you'd planned on? Good customer service would do what's necessary to keep you happy, because it was their fault.

Be well,

SJW

 

They will ship it to me, but I have to pay for it until I send the other one back. And then they pay me the difference back. And I am sure if I were to tack on a note to the return or even call customer service and ask for a refund on the freight charges, I would probably be ignored. I can certainly give it a try though. i will keep you guys updated as to the customer satisfaction that Summit offers

Matt

 

If they won't pay for the freight order the MSD through another source. I found mine at a local speed shop, they had it in one day

 

I might have to check that option out, but the only speed shops that I actually know where they are around here, arent actually speed shops. They are Advance and AutoZone. They might have it, but I would be paying $90000000 for a $500 part.

Matt