Published June 01, 2013
| Road & Track
The small-block Chevy is one of the greatest engines the world has ever seen. Thanks to its compact size, tremendous parts availability and general simplicity, it’s been the engine upgrade of choice for decades, whether you’re dropping it in a tiny sports car or a tire-shredding muscle machine.
The latest and greatest collection of powerplants being used in this manner is GM’s LS line of all-aluminum engines found in the C5-C6 Corvettes and the current Camaro. With factory power levels of 400+ horsepower for the LS2 and LS3, coupled with 25+ highway mpg ratings, it’s easy to see why the words “SBC swap” have become synonymous with inexpensive, reliable power. Of course there’s a new Corvette on the way, powered by a new engine, the 6.2-liter LT1 V8. With even more power (460 horses with the performance exhaust) and better fuel economy, can the direct-injected LT1 become the new darling of the conversion scene?
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I decided to ping someone who would actually know: Flyin’ Miata’s Keith Tanner. The company has been tuning the little Mazda since its introduction in 1989 and is renowned for its forced-induction and V8-converted Miatas. Flyin’ Miata is so confident in its work that it entered one of its V8 cars into the grueling Targa Newfoundland in 2011. Tanner feels that the biggest issue the LT1 faces in this particular segment of the tuning community will be GM itself.
“What’s going to make a difference for us is the availability of crate motors and controllers from GM Performance Parts (GMPP). Having a pre-programmed computer and wiring harness will make the LT1 swap easier,” Tanner says.
“One thing that will make a difference in speed of adoption is the changes in hard points and backwards compatibility with previous generations. Will it bolt up to existing transmissions and clutches? Headers? Oil pans? This won’t make a big difference in the more custom swap community, but it will slow us up with our ‘semi-production’ approach to parts.”
With those words turning in my brain, I headed straight to the source to get more information about the changes and backwards compatibility. According to GM’s Tom Read (Technology Communications, Powertrain) the “motor mount pattern and AC mounting are different. The top transmission mount bolt has been moved slightly off center to accommodate the direct injection pump.”
Those are relatively minor issues that the aftermarket will conquer in minutes. Adaptor plates are cheap, and many tuners already have to relocate motor mounts to fit in an LS engine, so no biggie there. The headache comes from that DI system. While you can currently use the ECU from a huge collection of GM cars to control an LS motor’s fuel injection system, that will likely not be the case with the LT1. I asked both Keith Tanner and Tom Read how they felt direct injection could affect things.
Tanner doesn’t think it’ll make that big a difference. “From a plumbing standpoint, you can feed the engine like a typical port injection one, as the high-pressure mechanical pump is on the engine itself.”
He also notes that people still put carburetors on the current LS3 V8, so you can never really be sure what’ll actually happen.
Read agrees. “My crystal ball tells me 20 years from now we'll be looking at direct injection like we look at port fuel injection today: commonplace everywhere. GM has been on the forefront of implementing DI and with the addition on the small block, almost all of our engines now use this fuel system.”
So, on to the catalyst for this lengthy bit of writing. There may or may not be a Guards Red Porsche 944 in my driveway with a bum motor. Should I be an early adopter and go LT1 (when a crate engine materializes), direct injection headaches and all, or just do what I can to grab an LS3? So many hard decisions …