Classic Chevy LS Engine Retrofit - Maximum Mill Enhancement

Retrofit a modern LS engine into your classic Chevy

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It's hard to know where to start when it comes to Chevrolet's Gen III and Gen IV engines. Upon first glance it would seem that the LS series of engines is evolving faster than any of Darwin's monkey theories. Let's make no mistake about it: hot rodding is evolving right along with them. In 1997 GM dropped its LT line of powerplants and announced the new and exciting 5.7L LS1 in the all-new C5 Vette. After decades of small-block development, GM had completely redesigned the concept of the pushrod motor and, in turn, developed what would eventually become one of the greatest engines ever stuffed under a hood.

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The new 345hp LS1 was designed from scratch rather than being a redesign of a previous engine, but GM did draw from all it had learned in developing the venerable Gen I and Gen II small-blocks. It wasn't long before people started to realize the horsepower potential of the all-aluminum mill. The aftermarket quickly started to churn out a host of go-fast and retrofit parts for these 346ci plants. No doubt that announcement had many Chevy owners chomping at the bit to be the first to acquire one of these new motors. Since GM's announcement of its new engine, there has been the LS1, LS2, LS6, LS7, and now the king of the jungle, the LSX (which we recently showed being installed into baseball Hall of Famer Reggie Jackson's Camaro in the May issue). The LS3 debuts in the base 2008 Corvette with no less than 430 hp and 424 lb-ft of torque. This torrent of LS power can seem a bit intimidating to those who hail from the carburetion generation, and with good reason. When compared side-by-side to its older brother, it can look almost alien. Looks aside, the proven performance and efficiency of this new generation of small-blocks is impossible to deny.

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Over the last several years the editors of this magazine have witnessed an ever increasing amount of these engines residing under the hoods of hot rodders. They are not just for owners of modern Corvettes, or for owners of the extinct line of fourth-gen Camaros. The LS engines are finding their way into every type of vehicle that has wheels. So, you may well ask, what does it take to retrofit GM's latest and greatest into the typical classic Chevy musclecar? The answer is both simple and complex. We decided to pick the brains of those who've gone down that road before us.

One of the first places we visited was Turn Key Engine Supply in Oceanside, California. The team at Turn Key Engine has carved out a reputation by building a series of out-of-the-box complete LS engines that are ready to go. Turn Key Engine Supply offers a complete accessory package for any LS1/6/2 engine. The kits come customized and even fully chromed if you're into the bling. Turn Key also offers wiring harnesses and custom programming.

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We asked Turn Key to give us an idea of some of the biggest problems it sees the average builder encounter when it comes to installing LS engines. The problem most noted was the fuel delivery system. When switching from an older carbureted engine to an EFI engine, it is absolutely necessary to update the fuel lines if not the entire fuel system, including the tank. A minimum of 5/8 to 1/2 inch or AN-6 lines tops the list. The guys at Turn Key told us they've seen builders use the same OE tanks without having them cleaned and have seen fuel lines that have 90-degree bends, another no-no for the injection system on the LS engines.

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Besides Turn Key Engine we called Tim Mason of HCC Performance in Dallas, Texas. HCC is a newer shop on the hot rod scene and has had experience with seven LS engine installs in Camaros, Chevelles and Tri-Fives. Mason concurs that fuel delivery is a top issue. HCC Performance prefers to use Rick's Hot Rod Shop as its source for gas tanks. Says Mason: "If you are going to go through the trouble of putting in a high-performance engine like an LS2, you might as well put in the best fuel system possible. For me, Rick's Hot Rod shop has the best product for our application. They use new GM/AC Delco pumps in their tanks that are capable of handling large amounts of horsepower and they use Aeromotive regulators."

What are other obstacles that may be encountered when retrofitting an LS engine? Mason's response: "Headers and oil pan clearance." Fortunately, companies like Street & Performance (Mena, Arkansas) have everything for LS conversions, including headers, oil pans and wiring harness systems.




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