1990 Corvette ZR-1 - An 18 month restoration.

duster

CCCUK Member
Some will remember this ZR-1, a 1990 black example then owned by Richard R, who occasionally ran the car in both ¼ mile and standing start mile events between 2003 and 2012. It was quick, having run a best ¼ in 11.72 secs at 118mph and, in the standing start mile, 172 mph. Since 2012, the car had been parked outside exposed to the elements, having experienced a small engine problem.

Having owned my own 1990 Charcoal Metallic ZR-1 since 2002 and not wanting to spoil her by doing any unnecessary work on her, I was looking for a project that I could work on in my retirement. Speaking to Richard in Dec 2018, I found that his black car was for sale, although with a caveat that ‘work was required’!. I jumped at the chance and in Jan 2019 purchased the car, bringing it back to Wiltshire on the back of a Transporter.

So began a really enjoyable 18 months during which time I carried out a comprehensive engine rebuild as well a multitude of other jobs, with loads of new parts fitted and some fabricated from scratch. The rebuild was helped by the fact that I had purchased a complete set of GM Kent Moore LT5 Special Tools including a Tech 1 in the early 2000’s, as well as amassing a collection of ZR-1 parts, just in case my Charcoal ZR needed them! Over the years, I had also collected full sets of workshop manuals etc and also found the ZR1.net of immense help. Well, with the engine back in the car and fully prepared for engine start, Friday 7th Aug 2020 arrived and – it fired right up and sounded very crisp!!

Since then, the car has been MOT’d and used occasionally on sunny days only! It is a very quick car, even measured against today’s supercars. Yet, it is so docile when driving around town.

For the technically minded, here is a little more info about the car:

The car has it’s original engine, gearbox and rear end fitted. The engine is running it’s stock pistons, rods, crank and cams etc, although the flywheel is an aluminum SPEC unit, together with a new stage 2 Carolina clutch and SPEC flywheel insert. Also, the injector housing port sizes have been increased along with the plenum ports. All ports have been matched. The injectors are 93-95 ZR-1 injectors which do not suffer from the harmful effects of ethanol. I have rebuilt the engine with new rod bearings and rod bolts, cam bolts, water pump, gaskets, seals etc as well as a new ATI Super Harmonic crank damper. Special attention was paid to everything!! Cam timing was checked, adjusted slightly, re-checked and checked again ad infinitum! With a complete set of LT5 Kent Moore tools available, everything was done correctly and to the manuals. The engine oil used is AMSoil 10W-40. New Samco coolant hoses were fitted plus new clutch slave and master cylinders. New fuel pumps plus sender unit were fitted. The gearbox was filled with Red Line Heavy ShockProof gear oil with a Carolina Clutch supplied countershaft shim kit fitted to help reduce any gearbox rattle on idle. The rear end is fitted with 4.10:1 gears. New drive shaft U/J’s were fitted. Outside of the engine, gearbox and rear end, the car has a new battery, cruise control servo, window and rear screen seals, new front tyres etc. It also had new paint on the right rear quarter. The car has Jeal headers with a Corsa exhaust system – to help keep inside noise levels down, the floor has been lined with Dynamat. The previous owner had also fitted large Brembo front brakes which effectively slowed him down after one of his standing start mile runs! He also fitted a short throw shifter. The brake fluid was changed with new Mobil DOT4 being used.

So, in conclusion, this matching numbers ZR-1 is very nice indeed. It has covered just under 56,000 miles since new in Sept 1990. To further improve the car, a new ZR-1 windscreen would be of benefit as the original screen is showing some delamination across the top. Also, a set of new Nitto rear tyres would undoubtedly help traction, especially through 1st and 2nd gear! And the interior would benefit from a new GM carpet set in the front.
 

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Oneball

CCCUK Member
Looks lovely, I remember reading a road test when they were new and the journo was blown away by not just the engine but the handling of the ZR1
 

TimP

CCCUK Member
Terrific post - a great looking car, especially in black. I remember reading about these when they first came out - certainly caused a stir with the performance!
 
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