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Corvette Engines from the '90s (including the C5s)
You saw it on the front page. This is the L98 installed in our 1990 Corvette. It was carried over from previous years, but got new emissions controls which eventually increased output to 245 HP. The real story on these engines though, is the torque: 345 Lb. Ft. at 4800 RPM which was good for 0-60 runs of 5.7 seconds.
Of course the big story for 1990 was the LT5 which was installed in the RPO ZR1 Corvette. It was known at the time as "The King of the Hill" and for good reason. While this engine maintained the traditional 350 CID displacement, it was all new. It's a four cam engine, with a dual port injection system, which utilized two injectors per cylinder to produce 375 HP in 1990. A "key" distinguishing feature was that the ZR1 had a separate key in the dash, just below the radio, which turned on the second set of injectors to keep horsepower down for valet use. When the key was in the "on" position, a "full power light" illuminated on the Driver Information Center. A foto of this is on the right. (Thanks to Corvette Forum member Aurora40 for this foto and for giving permission to use them here.) With improvements, the LT5 was producing 405 HP in 1995, its last year of production.
For 1992 the L98 was gone and replaced by a new 350 small block. Corvette brought back RPO LT1, last used in 1972, for this engine. This one is in a 1993 'vette. Besides the obvious visual difference in the intake, the new LT1 used a reverse flow cooling system which flowed coolant to the top of the engine first. Cooling the heads first pushed horsepower to a cool 300 -- pun intended. In addition, it used sequential port injection -- the injectors fired individually in timing with the engine timing. Performance was finally back in the "base" Corvette.
The 1994 evolution of the LT1 was the new LT4 350, but the LT1 was still available as a "base" engine. It was used through 1996 at which time it was rated at 330 HP. This was the only engine available in the 1996 Grand Sport Corvette.
The new C5 Corvette introduced in 1997 was installed with the new LS1 engine. For 1997 power was variously report as either 345 or 350. If the 350 HP report is correct, this marks the the first time since the 1970 LT1, that a traditional small block was making one horsepower per cubic inch. The picture on the right is interesting: Chevrolet allowed racing privateers to purchase a Corvette chassis with an LS1 installed so they could build their track car. I remember seeing one of these in a friend's garage near my home back in '98 -- it even had the blue plastic cover on the leather steering wheel. Of course all this, including the LS1. would come out and be replaced with proper racing equipment. This engine carried Corvette through until 1999.