How To Build An LS Engine: Short Block Assembly

Part 1: Prepping, Inspecting, and Assembling the 5.3 Iron Block of Our Summit Racing LS engine package

By Ryan Manson – Photography By Brian Brennan – Videography by Ryan Foss

When it comes to building a performance LS engine package, there’s no better source for not only those internal components but also the tools required to properly measure and inspect those components than Summit Racing. Not only does Summit stock all the usual suspects when it comes to engine parts and speed equipment, their private label line offers a laundry list of products with an eye toward quality and affordability. From the oil pan to the valve covers, we turned to Summit at every corner of our latest LS build, and they had everything we needed.

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Read More: Top 10 LS Engines

Speaking of performance LS and LT engine packages, the guys at American Heritage Performance have successfully carved out a niche in a market flooded with performance engine builders and aftermarket manufacturers. From their Archangel LS7 heads that powered the world’s fastest naturally aspirated Corvette C6 Z06 (8.895 seconds at 154 mph in the quarter-mile!) to their 700-rwhp 442ci stroker LS7 crate engine package; to say the American Heritage Performance crew know how to make power using the latest small block Chevy would be to put it lightly. That said, it should come as no surprise that when it came time to assemble a powerplant based on a 5.3L iron block, the American Heritage Performance crew were confident they could assemble a reliable engine that would make impressive power to boot.

01 Prepping Inspecting and Assembling the 5 3 Iron Block of Our Summit Racing LS engine package — The foundation for our Summit Racing LS engine build is this 5.3 iron block sourced locally and prepped by the guys at American Heritage Performance (AHP). Following the machine work, engine builder Kyle Martelli chased all the threaded passages in the block before giving it a thorough cleaning. A couple coats of gloss black engine enamel was the final step in prepping the bare block for our build.

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Keeping a tightly wound engine together requires quality hardware and for that end ARP bolts will be used from the main studs to the head bolts. A successful combination to be sure, American Heritage Performance’s Kyle Martelli will be bringing in his expertise to carefully inspect and assemble every aspect of the LS engine build.

To begin our build, an LS iron block was located, purchased, and disassembled before being delivered to American Heritage Performance. Once there, it was carefully measured and inspected before being deemed acceptable and sent off for machining. Decked, bored, honed, and brought within closer specs than GM could ever imagine, the bare block was then rolled into American Heritage Performance’s clean room where the build process could begin.

02 Martelli has organized an array of ARP bolts including head bolts PN 134 3609 and main stud nuts and washers — A clean workspace is paramount to a successful engine build, something Martelli and the AHP crew practice diligently. Here, Martelli has organized an array of ARP bolts, including head bolts (PN 134-3609) and main stud nuts and washers.

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Martelli will be inspecting the block first, checking crankshaft main bearing clearances before installing the cam bearings. From there, the crankshaft will be ready for installation and a few additional procedures will follow before the bottom end of our Summit Racing LS build is complete. We’ll come back next time and cover the rotating assembly, heads, and valvetrain before putting our mighty Summit Racing LS engine on AHP’s dyno where it will be broken in and its abilities demonstrated. MR

03 ARP main studs PN 234 5608 have already been installed in the block in anticipation of the first step of the build — ARP main studs (PN 234-5608) have already been installed in the block in anticipation of the first step of the build. A dab of ARP assembly lube is used before the studs are installed finger tight.

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Part 2: Wrapping Up the Rotating Assembly on Our Summit Racing 5.3 Iron Block Engine Package

Thorough block inspection is paramount to a successful performance engine build, and Kyle Martelli and the team at American Heritage Performance’s (AHP) attention to detail will no doubt show through when we put our LS engine through its paces on AHP’s dyno. But before that can happen, we need to continue with the assembly process, starting with the rotating assembly.

To continue with our Summit build, it should come as no surprise that we chose to use their LS Pro line of products for nearly all the moving parts in our motor. Starting with their 6.125-inch H-beam connecting rods and concluding with a set of their forged 2618 alloy pistons, the top end of our LS is a complete assembly of Summit Racing LS Pro parts. Like the crankshaft installation, Martelli inspected all the components, noted the results, and compared them to the specs provided by Summit and the bearing manufacturer. Pleased with the results, Martelli proceeded to file the ring pack to spec before assembling the piston/rod assembly. From there, using an ARP piston installation tool, Martelli dropped each slug pack into their respective cylinder, torquing every rod cap to spec via ARP 2000 rod bolts.

With the rotating assembly complete, Martelli then turned his attention to the installation of the camshaft. When it came to camshaft selection, we went with recommendations from both the AHP and Summit Racing teams, resulting with another selection from the Summit LS Pro line. Featuring 222 degrees of duration on the intake side and 234 degrees on the exhaust side at 0.050-inch lift, the resulting hydraulic roller tappet camshaft should provide plenty of low-end grunt, a good idle lope, and plenty of top-end power.

From there, Martelli installed the timing chain components and the high-volume oil pump. Front and rear covers were then installed, followed by a stock oil pan, effectively sealing up the bottom end of our short-block build.

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Part 3: Big Power From a Conservative Package

Wrapping up an engine build and strapping it onto a dyno can be an anxiety-ridden experience. Between the quality of parts we’ve used from Summit Racing and the experience and expertise from the guys at American Heritage Performance (AHP), we had no worries when it came time to start spinning the motor up and putting some numbers down. But first, AHP’s engine builder-in-chief, Kyle Martelli, still has a couple items to install before Kohle Heimlich can slide into the dyno operator’s chair.

The first task is to get the AHP-inspected Trick Flow cylinder heads assembled and installed. Once the cylinder heads were in place, Martelli measured for pushrod length before finalizing the valvetrain assembly. New sensors, spark plugs, AHP’s base dyno induction setup, along with the necessary wiring harness completes the preparation phase, and the engine is ready to be tested.

Before that, however, Heimlich uses the dyno to control the engine’s rpm and load to properly break in the engine. This helps seat the rings against the cylinder walls and ensure the valvetrain components are receiving oil as needed. After the break-in procedure, the fun can begin, starting with a few low-rpm runs, slowly increasing engine speed and adding a little bit of timing as required until the final dyno pass has been made. The resulting dyno numbers speak for themselves and leave us impressed. For a relatively mild LS build, we’re happy with the results and it should scoot our project down the road nicely.

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