Hi everyone. As shown in the trips and adventures section, I bought a 1994 ZR-1 last summer. It had father/son ownership before me and came out of Texas. It was pretty well kept but had years of TX dust and a few mechanical needs. This thread will show some of my projects.
The car has had a repaint. It is in average condition, showing well from a few feet with expected road wear. This is the day after she came to live with me.
First project: clean engine paint.
The factory finish on the LT5 engine is an argent gray paint. The finish is easily stained and can be damaged by harsh cleaning products. With 175k on the clock our engine wasn't going to be beautiful again short of professional refinishing but it a little cleaning would make it more presentable.
In these pics the back two pairs of runners as well as the intake above and cam covers below have been cleaned gently with polishing compound. Take a look at the tires and wheel wells, we will come back to them later.
The right rear fender was repaired in the past. Body repairs on a C4 can be tricky - many times a panel will look good for a few years but if regular bondo is used, over time the filler will continue to shrink and the repair will become obvious. The car didn't need a respray but the fender needed to be refinished so it was off to the body shop.
A little exploration:
The old filler is out and new, correct filler is in.
The white arc over the opening is just a reflection. From here the finish was polished and the car cleaned up.
The paint shop sent our car to a detailer to have the rest of the paint lightly polished before returning it to me. Overall the fender turned out nice. The color is a perfect match and you have to look at the fender just right in very bright sunlight to find the repair. You wouldn't notice it unless you were looking.
The car went to ZR-1 specialist Marc Haibeck's shop in Chicago almost as soon as the paint was dry. I drove it back to AR from Chicago and took it next to the annual C4 Gathering in Bowling Green (trip/adventure thread photo recovery is pending).
By the time we got back from BG it was apparent the detail shop had taken a shortcut that led to mucho headache for us. Check out how gnarly the wheel wells and upper fender liners under the hood look.
Funny, the car looked passably good when we left. WTH is this?
If you guessed "plasti-dip" you probably guessed right.
Actually I don't know for sure what this stuff is but it scrapes off with a fingernail and had begun to wear off over the 2,200 or so miles covered since it left Chicago. This won't do. Complicating things, the TX dust and dirt is still underneath the formerly-black coating.
So it was time for a good scrub anyway. Here is the halfway point on the underside of the hood. The right side sure looks better than the still-messy left.
Back in the mid-2000s I sometimes showed my Corvettes in judged car shows. We were autocrossing 10 or 12 weekends a year and picked up additional points in NCCC competition by showing. At time time my car was also a daily driver and I ran myself ragged keeping it respectably clean enough to go hoods-up in a judged show. It took a good 20 hours for a base detailing plus maintenance cleaning of 5-10 hours before a show to bring it back up to spec. If more than 2 months or so passed between shows another 20-hour cleanup was in the cards.
Well, all that stuff was kid's play compared to what lay ahead with our ZR-1. The Z probably hadn't had an underhood detail ever, or not in many years. As of 08/31/17 I'm over 25 hours into it and looking at another 10-15 to finish. Let's take a closer look at what is involved.
The plasti-dip scraped off pretty well on the upper fender liners but the lowers are a different texture and composition. Hello acetone, my old friend. This pic shows the front wheel well. Acetone has removed the plasti-dip on the top and leading edges, leaving a muddy residue that will have to be cleaned off as well.
Wheel wells "before".
The suspension will also need attention.
Ew.
Quick note on cleaners - CRC BrakeKleen (see what I did there?) and acetone are excellent degreasers and worked well on some suspension pieces. However, both can be bad for painted finishes. For safe general cleaning, I used Super Clean. It can be used straight but I prefer to dilute it 4:1 because it lathers and rinses better. For a spot-free finish I rinse with distilled water in a spray bottle. Super Clean comes in a gallon jug for $10 in Walmart as a concentrate and is even more economical when diluted. Here's their small bottle.
Now we're getting somewhere.
When cleaning the frame rails I noticed some small areas where the black finish had lifted from the primer underneath. No biggie, it happens. But I wanted to touch it up so it was less noticeable. I removed as much of the loose paint as possible and followed with chassis paint.
Before/after:
Touch up was carried through both sides of the car.
Here's a look at one small item. This is a hood stop on the front of the fender. I started cleaning it, then snapped a pic followed by another after it was done. Even with Super Clean and a boar's-bristle brush there was some residue around the base of the mounting nut. Had to go back over this again later.
I talked with an owner of one of these a couple of years ago and was surprised when he said the parts availability was pretty good for these. He mentioned the shop out of Chicago and said most ZR-1's go through there eventually. It was fun to really look one over and see all the little things that went into making the car. GM was ambitious when they made these.
Vigo
UltimaDork
9/1/17 10:33 a.m.
I'm pretty amazed what you can get these for. I am not a huge fan of C4s in general (im working on one for a customer right now that is really pissing me off, actually) but the ZR1 seems special enough to justify a higher price than what i see them going for. Maybe it's just a good time to buy?
Cool car/project.
Co-worker bought one a few years ago for what I thought was fairly cheap as well (or cheaper than I thought they would be going for). Was wondering about maintenance costs, but so far so good for him.
Nice work on bringing yours back to life. You have far more patience than I do.
One of these days I'll post some pictures of my c4. When I do I'd advise the op not to look at them. I really appreciate this level of detailed cleansing, but even the most ambitious would take one look at mine and hastily find a way to light the magnesium bits under the hood on fire, watch it burn to the earth, and consider it a community service.
The ZR1 was a big Lust of mine as a youth/high school kid. Love these. Back in the day, you could spot the ZR1 by their unique square taillights. I got giddy every time I spotted one.
Yours is a nice example, and it seems to have landed in good hands. Well done.
Great job on the cleaning. As a detailer, I can respect the fine details you're focusing on. It's amazing how much better a car will look overall when the small things are addressed.
NOHOME
UltimaDork
9/1/17 2:47 p.m.
While I could not see myself washing a car if you put a gun to my head, I do appreciate and admire the level of detailing an the results that you obtained.
I recall when these Vettes were current as I was working with performance Mercury outboards at the time, and wondering how they would hold up. Merc outboards being famous for speed but not durability.
Someone - GM, Lotus, Mercury Marine, the Creator, someone - did this engine right. It is all-aluminum with forged aluminum cylinder liners coated with Nikasil. Everyone else in the world had problems with first-gen aluminum/Nikasil technology, but somehow GM hit the lottery and trouble of any sort related to the block or bores is almost unheard of. Credit to Lotus for the design; the engines last and last. Mine is now at 178,xxx and isn't close to the highest mileage example out there. Every engine was run on a Dyno before it was stamped and put into production, which may have kept suspect units out of action. Total oil capacity is 12.5q with a 9.6q pan, which may play a role in longevity. I'm not sure anyone has found the practical upper limit on engine life. Some of the higher-mile cars get freshened up in search of more power or when the time comes to address lesser issues but not because they are wore out.
Indy-Guy wrote:
The ZR1 was a big Lust of mine as a youth/high school kid. Love these. Back in the day, you could spot the ZR1 by their unique square taillights. I got giddy every time I spotted one.
Yours is a nice example, and it seems to have landed in good hands. Well done.
Pretty sure all late C4's had those taillights?
I rode in a teal on white (Super Saved by the Bell theme) '90 C4 as a kid and I thought it was the coolest car on the planet.
Good job making this one pristine.
Vigo
UltimaDork
9/1/17 8:47 p.m.
Total oil capacity is 12.5q with a 9.6q pan, which may play a role in longevity.
That does sound helpful in making engines more resistant to spotty maintenance.
It's ironic that Lotus's contemporary 4v cylinder head for Dodge (Daytona and Spirit R/T) are so well known for cracking problems given that these ones are so reliable.
crankwalk wrote:
Indy-Guy wrote:
The ZR1 was a big Lust of mine as a youth/high school kid. Love these. Back in the day, you could spot the ZR1 by their unique square taillights. I got giddy every time I spotted one.
Yours is a nice example, and it seems to have landed in good hands. Well done.
Pretty sure all late C4's had those taillights?
I rode in a teal on white (Super Saved by the Bell theme) '90 C4 as a kid and I thought it was the coolest car on the planet.
Good job making this one pristine.
Later C4 Corvettes all got the square tail lights (not sure when), but not when the first ZR-1's first came out, ONLY the ZR-1's had them. (and a wider butt)
Car & Driver ZR-1 flash back article from 1990:
"The ZR-1 looks like a Corvette. There's that unmistakable shape but with a notable difference: The bodywork widens beginning at the leading edge of the
doors and culminates in a tail that is 3 inches broader than the normal Vette's—to accommodate the hefty P3 I5/ 35ZR-17 Goodyear Eagle Gatorbacks made
specifically for this car. The soft, polyurethane end cap is different too, convex rather than concave with square versus round tail lights and a small red
ZR-1 badge that graces the lower right corner."
I'm pretty sure they all got the square taillights for 1991 along with the new front bumper.
That level of dedication to detail makes a huge difference in the overall appearance of the car. I am definitely impressed, but I doubt I will ever be that dedicated.
Ok just a quick question. Is that a composite leaf spring on the front of the car? I'm not up to a high level of knowledge of corvettes and the suspension components.
Your before shots are cleaner than my car. Love the zr1 though!!
In reply to brad131a4:
Yes. Composite transverse monoleaf springs front and rear for the C4s. Odd design but it packaged well and handling was on par with or better than anything else in its day.
Thanks for the kind words everyone. A few small projects are left under hood, to be followed by stripping the wax, clay bar and polish.
Polished the upper and lower CAs and the steering knuckle. Cringed when I saw the second pic below because it shows I should have jammed a cleaning rag between the spring and LCA to clean the side of the spring in addition to the top. 
But overall, a good result. 
