Chevrolet LS Series Engines - Small Wonders

Of all the features of the LS1 that are out of the ordinary, the most obvious are the rocker cover-mounted coil assemblies. Each cylinder has its own coil and coil driver assembly with a short secondary wire connecting to each spark plug. The reasons given for moving the coils to the covers were the shorter plug wires lost less energy, so more was delivered to the plug as well as reduced radio frequency interference with on-board computers. A less noticeable feature is the change in firing order; no longer using the familiar 1-8-4-3-6-5-7-2 sequence, new engines fire 1-8-7-2-6-5-4-3.

With all that is unique on the LS1, one of the pieces that almost escapes notice is the oil pan, but there’s more to it than meets the eye. There have been a half-dozen or more cast-aluminum pans used on theses engines; the Corvette, or batwing pan, is a two-piece and has two wings to the sides, and the Camaro and Firebird pans have a shallow rear sump. But no matter what the shape is, in all cases the pan becomes a part of the engine’s structure when screwed in place and contributes to the block’s rigidity. Another unique feature is these pans also provide a mount for the oil filter.

Family Tree

General Motors’ new engines can be broken down into two series: Generation III and Generation IV. They share the same features and attributes in most respects.

Gen III blocks were made from cast iron in 4.8, 5.3, and 6.0L sizes (used primarily in trucks) and aluminum for 5.3, 5.7, and 6.0L. While iron blocks are heavier, they can easily be bored oversize during a rebuild; the aluminum blocks shouldn’t be bored more than .010-inch according to GM.

As we said, there are various versions of the Gen III, but the following are most sought after:

LS1: The 5.7L LS1 was the first in the Gen III series. The engine was used in the ’97 Corvette C5 and was later found in the Camaro, Firebird, and GTO. Horsepower varied from 305 to 350 depending on the application. A cast-iron version of this engine appeared in trucks in 1999.

LS6: Debuting in the C5 Z06 Corvette in 2001, this engine was an enhanced version of the LS1. The block was improved, the intake manifold modified, the cam was more aggressive, and compression was increased. While the displacement remained the same, the LS6 produced 385 hp when introduced, and it was cranking out 405 ponies by 2002.

While these engines were also found in the Cadillac CTS V-series, some may remember the ’70s when the original LS6 was a 454ci big-block.