lourib727

Excelent job on the write up.

jrzvette

this is a great resource.

As soon as I get a new color ink cartridge for my printer I plan on printing out all of the pics.

slicked25

Best example ever on the infamous Opti Spark replacement. Mine past away about 2 months ago and two weeks of depression later I found this topic. These pictures are so good that even my dumbass could figure out. It's really nothing to it if you put your mind to it but man, for all the hype on the Opti you'd think we were attaching a part to the Space Shuttle. I was scared to death of it. Also put a new o ring on the water pump too according to the book with crappy pictures. This guy could sell these pictures and from now on do all your project like this if you don't mind. BTW she's been running strong 2 weeks now. WPS

pmihaltian

Great post - WELL DONE !!

How much did the electric pump cost vs: an OEM replacement water pump? Also, are you satisfied with the electric pump's setup and performance?

murray59

Great how to! This one is bookmarked. I've been reading up on this in preparation for the day I need to do it on my 94. A couple of points:
- I see some comments that it's not necessary to remove the TB but I assume it makes the job easier.
- I saw another write up where they said remove the rad but I see you didn't.
- You didn't mention but I assume you put form-agasket on the engine side of the gaskets too.
- Crank pulley, does it line up in a particular orientation? lining marks?
- Dex-cool. Nothing wrong with Dex-cool but it must NOT be mixed with other antifreezes. You can only change over to Dex-cool if you have a proper flush done. (or so I've been told)

LT1*C4

Thanks a lot!

The cost of the Meziere pump was about $270 (USD) + tax's and whatever the shipping cost was. It was about $100 more expensive than the cheapest stock replacement pump I could find. I'd never used an electric pump on an LT1 before, so I figured I'd try it out based on many positive experiences of other LT1 owners who'd switched over to an electric water pump.

It's been about 2 month's now that I've running the Meziere unit and so far (knock on wood) I haven't had any issues at all. I do carry a few extra fuses just in case the inline fuse that comes with the pump ever fails - just to be on the safe side as I don't ever want to be left stranded in case I blow the original fuse.

The car runs noticeably cooler in stop and go traffic conditions like driving around town or idling in traffic but freeway temperatures remain unchanged from the factory mechanical pump, but I expected that from the beginning so no surprises there.

The car does "seem" to rev a little faster than before but I can't really say for sure. It may just be my imagination but then again, I've read many other LT1 owners noticed this as well. Who knows, maybe we're all imagining it

Power wise, the engine feels as if it pulls harder than it did before, particularly from around 4000 rpm and up. Not an huge change mind you, but enough for you to notice the difference.

Although I haven't gotten around to dynoing the car yet (I'll wait until I have a few more mods before I do) there are numerous dyno runs that have been posted by LT1 owners after this upgrade was performed and it seems that 8-10rwhp is about average for a basically stock/bolt-on LT1.

All in all, I wouldn't have any problem recommending an electric pump to other LT1 owners. It's been working well for me so far, keeps coolant temperatures lower than the factory pump (at low engine speeds) and seems to have free'd up a bit more power in the process.



- Bingo!

- Removing the rad would definitely have given me more room to play with, but I felt that I had more than enough room to get the job done with the rad in place.

Yes, I put a small amount on the engine side as well just to be safe.

- To be perfectly honest with you, it didn't even occur to me to check

Before I removed the crank pulley, I drew a chalk line straight down from top dead center with a little arrow pointing upwards so I knew exactly how the pulley was originally mounted and just went from there. Looking at the pictures though, it certainly doesn't appear as if there's any specific way the pulley should be positioned, but I'd recommend you just draw an arrow like I did, pointing upwards TDC just to be safe. It only takes a second to do and certainly couldn't hurt to do so.



After reading the original comments about me using Dex-cool, I got a little nervous. Did a quick search on google and found a few thousand threads filled with horror stories of blown engines and rusted-out radiators. Went outside, completely flushed the coolant system and filled it with the green stuff instead. :o

Although I had thoroughly flushed the system before I poured in the Dex-cool, after reading so many negative comments about the stuff, I just couldn't take the chance. (I'm paranoid like that)

It only cost me another $20 anyways so no big deal. Gave the Dex-cool to my dad in case he ever needs it.


Since the temperature outside dropped so fast so soon after me installing the pump, I never got a chance to take more photo's of the final install in terms of where I routed the wiring of the electric pump. Right now, I just have the positive cable running across the engine compartment, through the passenger side door and into the fuse box but as soon as it gets warmer outside, I'll route it properly, hidden, and out of the way like it should be. It will all look factory stock.

Stay tuned...

pmihaltian

Again, nice work - well done.

I'm sure many folks will benefit from your guidance and positive recommendations

slicked25

After removing my TB the gasket was 75% gone not to mention it's very greasy and dirty. Little shot of grease cleaner and compressed air with a rag will make it look mo better. I didn't go as hard core as the OP because with my luck and thinking it probably wouldn't crank anyway so why bother. But she did after the 3rd try and has cranked strong ever since not to mention she's addicting again. There's a mark on the crank pulley (you can't miss it) just make sure it's in the 12 o'clock position when installing the HB back on.

samsonb

Man, that is an awesome writeup. Almost makes me wish I had an LT1 so I could use it someday. Haha.



Do you like that pipe joint compound better than say Permatex high temp thread sealant?

1slov6

Great write up and pics. definatly something all of us with LT's will need to do sooner or later..Thanks

jimmymack

Please Mods, make this a sticky. Best opti-writeup I've ever seen

LT1*C4

I've used the pipe joint compound ever since I could remember and have been perfectly content with it's performance so far . The brush makes the compound really easy to apply and allows me to apply it as thick (or as thin) as I need it to be. It doesn't stain and cleans off easily enough should you get some on your hands or accidentally smear some of it in the surrounding work area.

I've never had any issues at all with it so I've never really felt the desire to try anything else.

That little can you see in that picture, has got to be at least 7-8 years old and its lasted me dozens of projects and it doesn't look like I'll be running out of itf anytime soon.

I usually stick with what's worked for me in the past so when this stuff runs out (probably 7-8 years from now) I'll just pick up some more.

Some friends of mine have used Permatex's high temp thread sealant and I haven't heard any complaints about it either, so I guess it does the job. I don't think anybody would have any problems with either of these two products, so just go with whatever you can find locally or whatever's cheaper.

mbrownle

Excellent how to. Best I've seen.

I plan to replace my opti as well. The only question I had was how to line up the new unit shaft correctly. Unfortunately the opti I bought does not have the flat spot on the shaft for proper alignment.

I guess I'll have to mark the rotor location relative to the flat spot from the old opti and replicate the flat spot on the new unit.

Any other suggestions?

mrmtrtrnd

Just found your thread and must say what a great job you did making this a project that someone like me can do. I will keep this for future reference. Thanks for the extra time and work it took to put that together.

rickneworleansla

Nice job with the write up. Very well done!


Here's my not-so-much of a write up but more like a how-the-fck is this done thread on installing custom cam, opti, ewp, double timing chain, valve train, etc., etc. There are some good tips, suggestions, explainations, and photos in there for anyone considering doing the cam also. The cam made a huge difference by the way but was also a hug PITA the first time around. Next time will be much easier.

It goes to show that with some mechanical ability, a lot of write ups, and help from the forum anything is possible. People really do appreciate someone taking the time to layout all the steps and make all the mistakes first. Comming soon hopefully will be my ported heads and intake swap write-up.

I also really like the Mezierre. It's nice to be sitting in bumper to bumper traffic and watch the temps stay right where they are, sometimes even drop.

Keep up the good work CF!

t8j1w72

well done... I'm in the process of changing my water pump right now and while I'm at it and everyone suggests, I'll be putting a new Opti in. This is a great help...thanks for your time.

joesgulfstream

You should write a manual for corvette dummies. It was great almost anybody could understand it. I will save it because I am one of those " DUMMIES "

GM Junkie

I'll add my cudos to all the others here - great work. I'll be using this real soon when I do my WP repl. this month. BTW, for those who might be interested, I found a brand new in-the-box Bosch pump on Amazon for $87 - had it shipped "super snail mail" (3 weeks) for free. Check it out.

AustinJohn

LT1*C4 - Fabulous writeup and pictures. I will be following it this week as I replace the Opti, water pump, thermostat and driver side valve cover gasket on my '94.

One question: I've seen other Opti writeups in which folks used RTV, etc to "seal" their Opti yet you didn't do that. Any thoughts from you or other readers would be appreciated.

Thanks in advance!

John

LT1*C4

I've run a bead of sealant around opti-sparks many times before on previous vehicles - although for the record, I can't confirm with any certainty that running a bead of silicone around the opti-spark actually prevents moisture from getting in. I mean, it certainly couldn't hurt anything either, but I really can't comment on it's effectiveness.

On this project, I actually did run a bead of high temperature silicone around this opti-spark before I put it in. However, I didn't bother to mention it because as I said, there's no solid evidence as to how well it works (or even if it does anything at all) so I just left that part out all together. It's up to the individual really, but there's no proof either way that silicone does anything...

It's all up to you