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Building a LS1 Engine for Performance and Reliability

Third Time’s A Charm: More than 20 years ago, GM’s all-new Gen III V-8 launched a new era of power, efficiency, and respect

Jim Smart Aug 11, 2017
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Talk about a quantum leap in technology and performance? This is a story at Chevrolet that dates back more than 60 years to the most popular American V-8 ever produced. The small-block Chevrolet V-8—displacing 265 cubic inches—debuted in the all-new 1955 Chevrolet. Imagine the excitement of compact overhead valve V-8 power at the time. It was quite the departure from the antiquated Stovebolt inline-six, launching a new era for Chevrolet; along with those fabulous Tri-Five 1955-’57 Chevys.

The small-block Chevrolet V-8, known as the Gen I remains in production to this day as a terrific Chevrolet Performance crate engine for virtually anything that rolls because it fits nearly anything imaginable. At the cusp of the 1990s, GM engineers looked at what it would take to vector the Gen I small-block toward the new millennium. They came up with a short-term solution in the Gen II small-block, which wasn’t much different than the Gen I with the exception being Opti-Spark ignition and a cam-driven water pump.

Chevrolet would quickly learn the Gen II small-block was a stopgap but just wasn’t enough to close the gap. Fundamentally, the Gen II was a step in the right direction; however, it became necessary for GM to begin all over again with a clean sheet of paper like it did early in the 1950s. The time had arrived for an all-new pushrod V-8 conceived from scratch. GM began with what they knew already worked—the same basic bore spacing and dimensions—yet approached the new Chevrolet V-8 in a totally new way. It would be a corporate V-8 that was long on potential and growth and would be shared along all car lines.

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GM product planners and engineers came up with the LS1, or Gen III V-8, which the press called the new small-block Chevy at the time. However, the LS1 was not a small-block Chevy, but instead a completely new GM corporate V-8. If you look at the LS objectively and without bias, GM took all the best aspects of the small-block Chevy and the small-block Ford with a smattering of Ford Modular block technology to conceive what is undoubtedly the best all-around American V-8 ever produced. The LS had its share of teething issues when it was introduced in the Corvette in 1997 and the F-body Camaro and Firebird in 1998. However, GM managed to get through these issues, massaging the LS into an incredible family of powerful V-8 engines.

Because the LS1 has been around now for 20 years and been driven a lot of miles in that time in a wide variety of GM vehicles, we thought it appropriate to look at the original game-changing LS1 and share its features. We’ll follow along as Derek Ranney at L&R Engines in Santa Fe Springs, California, walks us through the build process in preparation for some time on the dyno.

We’re building the LS in Part 1, so stay tuned for Part 2 where we’ll wrap up this build and put it in the capable hands of Steve Brule at Westech Performance to see what it will do on the dyno.

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1. The LS1 and LS6 were produced between 1997 and 2005 in the Corvette, Camaro, Firebird, and the GTO. The LS6 showed up in the 2001 Corvette Z06 and lasted through 2005. It was also introduced in the Cadillac CTS-V. Although the LS1 and LS6 engines share similar nuances, the LS6 sported structural enhancements to the block along with bay-to-bay breathing, which made the LS6 a better block. The LS1 block shown here has been fitted with ARP main studs and bolts for incredible strength across the main caps.

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2. Eagle Specialties has provided us with Mahle forged pistons tied to these incredible forged I-beam rods. The complete bottom end dynamic balance job weaves smoothness into the power package. Ductile iron file-to-fit rings will provide exceptional sealing and wear.

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3. We looked to Comp Cams for inspiration on this LS1 build and it came up with a hydraulic roller cam (PN 54-455-11) designed more for brute low- to mid-range torque rather than top-end horsepower, though we expect good horsepower numbers from the FAST induction system. This cam offers valve lift of 0.604/0.610 intake/exhaust along with 264/272-degrees duration at 0.006-inch with 112 lobe centers. The result is a smooth idle and great off-idle response when the butterfly is opened.

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4. This is what’s known as the barbell, which controls oil flow to the oil filter. You don’t want to forget this item or you will have zero oil pressure.

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5. Mahle file-to-fit ductile iron rings are ground to fit then installed on the pistons. The ring end gaps are ground to size and chamfered for smooth function. Ideally, you would use a ring expander during installation to prevent ring distortion.

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6. Aluminum bearings have been fitted to the rod journals. The surface between the bearing and the rod must be dry. Never use oil or lube between the bearing and the rod or between the main bearings and the block. You want the proper amount of bearing crush for security. Use plenty of engine assembly lube between the crank journals and both the rod bearings and the main bearings.

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7. The reciprocating parts, namely the rods and pistons, are installed next. The pistons, rings, and cylinder walls can be coated with assembly lube or SAE 30 weight engine oil. It is suggested you use SAE 30 or 10W30 weight engine oil on these surfaces to ensure proper ring seating. If you intend to store the engine for an indefinite period of time, use engine assembly lube.

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8. While you’re in this neighborhood, make sure the connecting rods are installed facing the right way. You’d be surprised how many people get this wrong. The pistons with reference marks go toward the front of the block with the valve reliefs facing up. The shoulder of the rod goes toward the shoulder of the journal. The rod bolts are torqued in thirds to the final ARP specs.

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9. The rod bolts are properly torqued to ARP specifications and marked as torqued with a marker. Marking the bolts ensures you have torqued each one. L&R Engines uses electronic torque wrenches on all of its engine builds along with double-checking the final torque spec.

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10. The block cam plate follows cam installation. ARP bolts secure the plate to the block.

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11. The Melling 295 oil pump from Summit Racing Equipment is primed with engine assembly lube prior to installation and the bolts are treated to a thread locker prior to installation.

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12. The timing chain and gears are installed before the oil pump, working with the timing marks.

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13. When you install the LS1 oil pump, make sure the pump is evenly centered on the crankshaft with no side-load. A side-load will ultimately damage the pump.

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14. Replacement timing and rear main seal covers are available from Rock Auto complete with gaskets and hardware for your LS project. You can build an LS from scratch right down to the last nut and bolt using new parts.

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15. The one-piece rear main seal is made of Teflon and does not require lubrication. L&R Engines discourages the use of lubrication, which will actually damage the seal.

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16. Here, the windage tray and oil pickup have been set in place. All of these parts are new.

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17. The windage tray ARP fasteners get a thread locker and are torqued to Chevy specs.

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18. The timing cover is carefully installed. You don’t need sealer on the LS timing cover because sealing technology is that good. Areas where you have multiple joints may require a tiny dab of Permatex’s The Right Stuff, available from Summit Racing Equipment.

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19. This is an aftermarket replacement cast-aluminum oil pan from Rock Auto. It is authentic in every possible way and will fit both automobiles and trucks. The cast pan provides block rigidity and better heat transfer than steel.

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20. This LS1 oil pan gasket from Fel-Pro, available from Summit Racing Equipment, is positioned for pan installation. Again, no need for sealer. Lay it on and install the pan.

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21. Summit Racing Equipment offers this groovy underdrive harmonic damper for your LS1 project. The Summit damper frees up power and provides smoothness. We’re going to use a stock damper for our dyno testing because, ultimately, this LS mule is going into a truck.

Photos: Jim Smart

Sources

Summit Racing
Akron, OH
800-230-3030
http://www.summitracing.com
Rock Auto
Madison, WI 53719
www.rockauto.com
Eagle Specialty Products, Inc.
Southaven, MS 38671
662-796-7373
www.eaglerod.com
L&R Engine
Santa Fe Springs, CA 90670
562-802-0443
www.lnrengine.com/
Federal-Mogul
Southfield, MI 48034
248-354-7700
www.federal-mogul.com
ARP
Ventura, CA 93003
800-826-3045
arpdiesel.com

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