*photography by: the author
Converting a junkyard L92 into an LS3 on the cheap and dirty
If you’ve got LS3 envy but lack the budget to buy a crate or salvage one to stuff under your hood, there’s a more budget-friendly alternative out there most people don’t know about. While the Corvette, Camaro, Pontiac G8, and the Caprice got the unadulterated version of the LS3, several models of trucks and SUVs received the L92/L94/L9H code 6.2L V-8.
When the LS series first debuted in 1997 model Corvettes and 1998 model F-bodies, they heralded the beginning of a new era of small-block performance. But it wasn’t until the series started leaving the factory under the hoods of the millions of trucks GM built that engines became truly affordable for swaps into various GM vehicles (along with more than a few brand X models, too) and even someone on a tight budget could experience the benefit of LS power. Now with the LS3 becoming the benchmark for out of the box power, the truck line once again provides a more budget-friendly way to get serious LS displacement and power without breaking the bank.
The L92 was first produced in 2007, installed in the Cadillac Escalade. It was later installed in Chevrolet and GMC trucks and SUVs. It came from the factory with a 403 horsepower rating, variable valve timing, and used the same heads, block, and crankshaft as the LS3. When it was later modified for Flex Fuel capability it received the designation L9H and L94, but the long block stayed the same. Pictured is an L94.
The L92/L94/L9H uses the same block and rectangular port heads as the LS3, but on top it utilizes a rectangular port version of the “Big Ugly 2” truck intake. Internally the L92/L94/L9H uses a different camshaft that is drilled to provide oil flow to a hydraulically operated cam phaser mounted onto the L92/L94/L9H specific cam gear, also requiring the use of a unique timing cover. The L92/L94/L9H also features pistons with slightly lower (and we do mean slightly) compression due to cast in valve reliefs for the variable valve timing.
While a salvage LS3 can cost in the neighborhood of five to six thousand dollars, L92/L94/L9H s can usually be had for around $2500. That’s less than half the price for essentially the same engine. And converting an L92 to LS3 specs is easy and cheap, for around $500 depending on what intake you’re going to use.
We had everything converted on the engine in less than a day, and another day reinstalling the engine. Bolted to AntiVenom Performance’s Dynojet chassis dyno, our converted L92 pumped out 414 horsepower to the rear wheels. From experience, we’ve seen stock LS3s turning manual transmissions make anywhere from 350-375 at the wheels.
So, the bottom line, when all costs are figured in, you can get LS3 power and potential, without the purchase price of an actual LS3, thanks to the hidden gem of the L92/L94/L9H hiding under the hoods of trucks and SUVs all around us.
The destination for our converted L92 is a C4 Z06 that’s driven primarily at track days and similar events. During an event at Daytona, something let go in the engine and it went KA-BOOM!
It wasn’t until the dead LS1 was torn down that the culprit was discovered. A lifter had failed (left) and locked up the cam, which in turn took out the timing chain, while the crank still spun and caused piston to valve contact.
The piston to valve contact was evident once the heads were pulled. In the end the engine was deemed junk and not rebuildable.
One of the cylinders had a massive crack in its wall, several pistons had valve impact marks in them, and the heads would need heavy work to have any chance at being reused.
Our salvage L92 came from a 2010 Escalade that had been wrecked in a rollover accident. We picked it up for $2,500 with the factory truck intake still on it. We swapped that out for a factory LS3 intake that would work in the C5 for hood clearance.
The main thing you’ll need to convert the L92/L94/L9H to LS3 standard is the LS3 timing cover (part no. 12633906) and three-bolt timing chain set (available from manufacturers such as Comp Cams, Summit Racing, Chevrolet Performance). You can install pretty much any cam you desire in place of the stock cam. For our setup, we went with a budget friendly C6 ZR1 cam we had at the shop. We also switched the valvesprings to LS3-spec springs. Since our engine was going into a C5, we needed to install the oil pan from the LS6 we pulled out of the car.
Source :
Patrick Hill
Patrick Hill has grown up around the automotive aftermarket, and carries a lifelong passion for performance, racing and automotive nostalgia that spans from the Tri-Five era to the current modern performance market.
