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Converting a Fourth-Gen V-6 to an LS EngineThe Big Swap From the December, 2012 issue of GM High-Tech Performance By Scott Parker Photography by Jay Heath, Scott Parker
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Those of you longtime readers may remember our good friend and fellow SIM Editor, Mr. Jay Heath, the former owner of our '99 LS1 Trans Am project that raucously pounced Englishtown Raceway Park with such proficiency using mere bolt-ons until its final days when it received a ProCharger. Jay has owned several Firebirds over the years, and once again decided to return to the Big Chief. But the problem he faced was one that no doubt many of you have, if you were in the market for a fourth-gen recently. He wasn't willing to pay C5 money for a fourth-gen LS1, and there wasn't much in that price range that didn't need significant work (if it was salvageable in the first place). Thus came the nearly regrettable thought of purchasing a V-6 Firebird and using the leftover money to convert it. Now for a gutted racecar, using a V-6 car is a no-brainer. But if you actually want functioning OEM gauges, creature comforts, and reliability suitable for a daily driver – that is going to take time, effort, and some real craftiness. And of course, if you are looking for craftiness, AntiVenom is the shop to call. Owner Greg Lovell is a wellspring of craftiness, and he was able to make the impossible possible. Having built, stripped, and parted out more fourth-gens than almost any human on the planet he happened to have possession of nearly every part needed to complete the swap. For those of you attempting this at home, I suggest you start gathering the parts you see in this story over the course of the next year. If you don't already have a head start, it is going to take some time or a full parts car. In case you are wondering, Greg said wrecked LS1 fourth-gens cost on average around $1,800 (though as little as $750). And the faded black '99 Firebird (here-to-forth known as Ashy Larry) that Mr. Heath purchased cost a scant $1,400. Doing quick math, you can recreate this swap at home for $3,200 total, including the price of the car.  Ashy Larry, our ‘99 Firebird,...  Ashy Larry, our ‘99 Firebird, came from the factory with a 3.8L V-6, which we had no intention of keeping (sorry V-6 lovers!). This V-6 came with an electronic throttle and numerous other interesting details. Virtually nothing off this engine could be salvaged or reused.  AntiVenom got started by removing...  AntiVenom got started by removing the intake tract, hoses, cutting the exhaust, unbolting the driveshaft, and unplugging the engine harness from the body harness before dropping the motor, trans and front subframe out of the car.  Tech Kyle Miller was putting...  Tech Kyle Miller was putting the finishing touches on the L92 engine that AntiVenom outfitted with an LS9 cam, LS3 lifters, pushrods, timing set and cover. This engine was a take-out from an Escalade with low miles that had bent a few valves. By replacing a few valves and milling the heads, it was good as new, and came at a great deal – $3,200. It was topped off with an LS3 intake manifold, 90mm cable throttle body, LS1 F-body balancer and oil pan. AntiVenom frequently has deals on 6.0 and 6.2L engines, which generally cost about $2,500 prior to any machine work or parts. But as you might suspect from GMHTP, we had no intention of using a bunch of stock parts that would prevent this Firebird from keeping up with all the modern muscle we encounter on the streets today. We made a few key upgrades to enhance the performance. Instead of using a stock LS1, we sourced AntiVenom for a 6.2L L92 from a low-mile Escalade that had a few bent valves that were replaced. To make it compatible with an LS1 PCM the VVT phaser and camshaft along with the DOD lifters were replaced by LS3 lifters, timing set, cover, and an LS9 cam (for more on this popular swap stay tuned for a later issue of GMHTP). Out the door the total cost for this setup is $3,200, which does not include an LS3 manifold (leftover from a previous project) and 90mm cable throttle body from AntiVenom. To rectify the compatibility issue with the 58x reluctor wheel, Jay also picked up the Lingenfelter Crank Sensor Trigger Conversion Module. To complement the 6.2L we made sure to pick up some high-flowing intake and exhaust components as well as a well-built transmission. The folks at Hooker Headers had a brand-new set of Super Comp 1 7/8-inch ceramic coated headers and 3-inch mandrel-bent exhaust with an Aerochamber muffler ready to ship out when we called them, so the process couldn't have been any easier. If you haven't installed a set of Hookers in a while, these long-tubes are worth giving a look. The larger primary tubes, 3/8-inch flanges, and the Power Spear in the 3-inch, 4-into-1 collectors (to aid scavenging) really ups the ante. An air intake was sourced from K&N Filters, the 50-state legal FIPK, though we later found out that the V-6 and V-8 models use the same upper radiator support, so a stock style air lid will also work. Regardless of which route you go, the key is to not use a stock piece here if you want to make power. Last but not least, we called Performabuilt transmissions for one of its 4L60E Level 2 packages with a billet 9-inch converter. This stout piece comes complete with upgraded clutches, bands, and a full two-year warranty. With parts in hand and our Ashy Larry project on the ready, we headed off to AntiVenom in Seffner, Florida to commence the 48-hour overhaul. Follow along for the details.  Using an engine hoist, the...  Using an engine hoist, the L92 is dropped onto a new V-8 K-member from a ’98 TA parts car.  The K-member, stands, and...  The K-member, stands, and motor mounts must all be sourced in order to complete this swap.  The engine and K-member is...  The engine and K-member is placed on to a hydraulic cart where the V-8 steering rack and other components are added. A V-6 rack can be used, though it has different ratios. For optimum performance and feel, we’d recommend the V-8 version.  Also sourced from the parts...  Also sourced from the parts car is the accessory drive system including the tensioners, idlers, and power steering pump. Though we could have also reused an old water pump, alternator and A/C compressor, these are not areas that you want to cheap out on. Purchasing new parts locally ensured years of reliability.  It is important to note that...  It is important to note that the accessory drive system is unique to the F-car LS engine (including the balancer). Not only do none of the parts interchange with the V-6 stuff, but also not with truck or Vette parts. Thankfully all the accessories will bolt right up on any LS engine, with one exception being the 6.0L truck block that is missing one tapped hole (easily fixable).  Greg lays out a new GM wiring...  Greg lays out a new GM wiring harness and plugs it in to the appropriate locations such as the injectors, MAP sensor, etc.  Notice the V-8 specific hose...  Notice the V-8 specific hose for the brake booster.  The fuel system is yet another...  The fuel system is yet another area of note that must be addressed. The V-6 uses a return style fuel system (with the lines on the left) and lower volume pump. The easiest solution is to source your parts car for new lines and a complete tank (with pump).  Those requiring more substantial...  Those requiring more substantial fuel systems can outfit the V-6 lines with a fuel pressure regulator, but for our n/a motor that would have been overkill. The factory return-less setup with a plastic ’98 fuel tank and pump was our modus operandi.  Since this Firebird is a ’99...  Since this Firebird is a ’99 we also had to upgrade the U-joint coupler to mate to the V-8 rack, 2000-02 models use the same piece on both V-6 and V-8. Once again we purchased a new part to ensure reliability since this is a wear item.  Here you can also see the...  Here you can also see the difference in A/C lines, the bottom being a new GM piece for the V-8.  The electronic throttle requires...  The electronic throttle requires changing from the gas pedal on the right to a sourced set of pedals (left). Since the pedals are separate on the later V-6 cars, it is easiest to cut the V-8 gas pedal from the brake pedal and install rather than go through the trouble of removing the steering column to access the whole assembly. Earlier V-6 cars with cable throttles needn’t go through this ordeal.  A new GM throttle cable was...  A new GM throttle cable was purchased from Scoggin-Dickey Parts Center, inserted into the firewall, and connected to the gas pedal on the other side. Be careful to ensure there is proper slack in the cable or the throttle blade will not open or close all the way.
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Camaro ZL1 Morphs into “Freedom Fighter”
In a post-9/11 world, there are a multitude of organizations and individuals dedicated to helping veterans, both human and canine, adjust to life back home and aid with their health problems --...
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