Ruthless Pursuit of Power: Our In-Depth Look at the 2008 Corvette LS3 Engine - Page 1 of 6




Ruthless Pursuit of Power: 2008 Edition - Page 1 of 6

Our In-Depth Look at the New 2008 Corvette LS3 Engine

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Image:  Author © 2007 by Hib Halverson
No use without permission, All Rights Reserved

I turned left on I-65-north on-ramp, then buried the gas.

First: exhilaration

In seconds, I was near the top of third gear, watching traffic fly backwards when I lifted. This twenty-oh-eight, six-speed–new LS3 under the hood and optional "NPP" exhaust out back–was a freakin' rocket ship.

Then: despair.

I realized that now, my '04 Z06, good old "3Balls39", can't even keep up with a base C6. The new engine–6.2-liters, 436hp@5900 rpm–makes the standard Corvette about half-a-tenth quicker than the most aggressive Vette of just 48 months ago.

"This sucks!" I blurted.

The GM guy with me almost got a word out.

"Dude!" I cut him off. "The motor's awesome! What sucks is that it took you guys only four years to make a base car quicker than my 110-lbs. lighter C5Z."

At 75 in sixth, the '08 cruised effortlessly, demonstrating once again that wide "bandwidth" (cutting-edge performance combined with darn nice road manners) which has been a hallmark of America's Sports Car and the envy of some of the world's other great car makers since the ZR-1 years of the early-90s.

From the outside, the LS3 case looks like last year's LS2. If you have sharp eyes, you can see the larger bore, but the other major change is deep inside.   Image:   GMPT CommunicationsAs we rolled towards Bowling Green and the National Corvette Museum, I reflected upon the LS3. General Motors' Generation-Three and -Four Small-Block V8s are some of the World's great engines. Don't believe it? Just ask Mercedes-Benz. When it owned Chrysler, it copied–oops–it benchmarked GM's Gen 3 Small-Block architecture then reproduced key aspects of it in its current Hemi V8.

Short Block Details

World-class engines have robust blocks, or "cylinder cases," as powertrain engineers say. The '08 Vette's 378-cubic inch, LS3 uses the same block as the L92, a high-performance Vortec 6200 truck engine. But–don't start flaming us about SUV motors. The L92 is light, compact, reliable, durable and powerful–just the foundation a Corvette engine needs.

The LS3 case shares basics most aluminum Gen 3s and 4s have had since that engine family debuted in the 1997 Corvette: deep skirted, 319-T5 aluminum block with siamesed, cast-in-place, gray iron liners which are centrifugally-cast to increase density and allow thinner walls, long head bolts threading deep into its main bearing webs and six-bolt, steel main bearing caps. All this makes a lightweight, rigid, block structure offering good durability and reduced friction.

Chrysler borrowing from that block design for V8s in its own full-sized trucks and performance cars says much about GM's engine technology. Some might be disbelieving of the Gen 3/4 block being so inspiring to a competitor but, if you ever see the two short blocks disassembled, side-by-side on a bench; the influence will be obvious. Imitation is the best form of flattery.

There are improvements in the LS3 block. Compared to last year's six-liter, the liners have .084-in larger bores, its main bearing webs are about 20% stronger and their "windows", which enhance "bay-to-bay breathing" in the interest of oil control and reduced parasitic loss, have been somewhat enlarged.

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