"You can't keep a good Vette down." That's the mantra for this Corvette. But it only describes half of the equation. The other half would be dedicated, unyielding, relentless, and driven. However, while all of these words are suitable for any Corvette, no matter the vintage, they aren't destined for the fine automobile we've come to love. No, these are words best used to describe the owner of this '86 ZR-1, Keith Beschi. But wait! Wasn't the ZR-1 produced from 1990-95? The answer to that question would be, "yes." But as we all know, several years of development go into any car produced by GM, and the ZR-1 was no stranger to this prototypical process. This is the story of one of them.
Back in 1985, GM took over Lotus Engineering in Norfolk, England. The C4 needed a flagship with unbeatable power; so why not get a company renowned for performance engine production to make it? Under the guidance of the very resourceful Tony Rudd, a project was under way using a V-8 engine that Lotus had already developed but had not been placed in any vehicle.
The criteria of no modifications to the Corvette chassis, coupled with 350ci, 4.4-inch bore and the other traditional stuff while needing to produce 400 bhp, was a tall order. A compromise was made and 375 bhp was settled on. So after much scratching of heads, the LT5 was spawned-a completely new engine with 16 valve heads.
The project started early in 1985, and the first engine (Phase 1) startup was on May 1, 1986. This testing showed many problems that lay ahead, namely that the single-row (simplex) timing chains were not up to the job. The engine design also had a tendency to release all its oil if run over 4,000 rpm, so a redesigned oiling system had to be devised.
Enter the Phase 2 engine with revised oil systems and, eventually, twin (duplex) timing chains.
By November 1987, a Phase 2 engine had achieved 200 hours on a test bed with a computerized load and part throttle program.
With the new LT5 proven, there was now a lot of road testing to be carried out. I've heard rumors of ZR-1s traveling in convoy at 150 mph on the M11 very late at night. Well it's a job and someone has to do it, right?!
Now that the engine was making good progress, external cosmetic changes were made to take into account the need for better airflow. The Phase 3 engines were very near to the final article, but much more internal refinement was required.
The Phase 4, 5, and 6 engines all had minor external changes and modifications made to them as the process neared a working product. The engines that finally made it into mass production were the Phase 7 motors, and, in fact, the 84 '89 ZR-1s were produced using this new standard.
When the ZR-1 was announced in 1989 and released to the press, the publicity was sensational. Almost everyone who drove the car raved about the performance. However, for various reasons, the new series of Corvette was held at pre-production stage until the '90 model year. None of the '89 models were sold to the public.
Sadly, the small, for GM, production of this brand of Corvettes came to an end in April 1995. Curiously, the last ZR-1 engine to be built at the Stillwater, Oklahoma, Mercury Marine facility was made on the 24th of November, 1993. All engines built for later years were stored for the relevant model, which included the more-powerful 405-bhp version of the engine, which made it into the '93 model year.