Chevrolet Corvette ZR1 LS9 Engine Specifications - Domestic Exotica

This device is specific to the LS9 assembly process, and is used to guide the rod into the engine. Besides making sure the rod end doesn't injure the bore or crank journal, it also ensures the rod doesn't damage the oil squirter...

...The reciprocating assembly is strong and lightweight, consisting of titanium rods, along with forged aluminum, friction-coated pistons.

The LS9 also features this new integrated oil cooler to help deal with the supercharged engine's greater oil system demands; in fact, the dry sump system capacity was increased and its scavenging ability improved as part of the package. The increased pressures involved with forced induction meant that even items as innocuous as the oil filter needed to be strengthened, so this new ACDelco oil filter-which should fit any LS engine-has an extra-thick canister to resist bulging.

Each station is configured to carry out a specific task, and only the tools needed for that task are on hand. The task sheets are color-coded green for LS9 and white for LS7 engines. See the screen with the green happy face? This is one of the three check stations found throughout the build. If a step is skipped, the face will be red and sad until the situation is remedied. Also notice the white templates-they show which order the bolts need to be torqued in. Before the builder can torque down any bolt he must first scan the appropriate bar code for that set of bolts. This sets the torque wrench to the proper setting and prevents errors, since the system won't let the builder scan the next fastener until the previous has been scanned and torqued.

As you might expect, GM has a number of specialized tools for assembling engines. There's an alignment tool to make sure the timing cover is dead center to the crank, and this plate ensures that the bottom is flush to the block to ensure a leak-free seal to the oil pan. Also visible is the LS9's higher-capacity oil pump, installed to ensure adequate oil pressure at the high-cornering loads the ZR1 is capable of.

One critical issue, of course, was increased stress placed on the top end; the LS9 has to deal with a 30 percent increase in cylinder pressure created by the forced induction setup. "The pressure is literally trying to lift the head off the block," explained Guard. The team developed a new gasket with four active layers for the LS9. "We needed more 'spring,'" Guard said. Each layer allows for 5 microns of movement, which covers the 18-20 microns of movement that were needed under this pressure. Final validation testing with the gasket, Guard said, was "perfectly uneventful."

The cylinder head bolt size was increased from 11 mm to 12 mm, a step that was needed "just to hold the head on," said Guard. At Wixom, this literally over-the-top tool torques down all 15 head bolts in one single operation. It takes less than five minutes to install a head in this manner, making it extremely efficient.

The head bolt torque operation is of course carefully monitored. If any bolt reads outside the required torque spec, a red or yellow light indicates which one needs further attention. The computer also records this data-both torque and angle-and keys it to the serial number of the engine for future reference.

Showing a further refinement upon the LS7 platform, the LS9 uses rails beneath the rockers to help improve valvetrain control at high rpm. The heads themselves, on the other hand, aren't as exotic, but are certainly effective. They're designed specifically for the LS9, but are close cousins of the LS3 and L92 heads. The rotacast LS9 heads have winglike shapes cast into the intake runners to induce swirl and improve the mixture motion of the pressurized air/fuel charge.