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All three generations were outfitted with either [[aluminum]] or [[cast iron]] engine blocks, with all passenger car engine blocks being aluminum, whereas truck engine blocks could be either material. Every single engine was also fitted with aluminum cylinder heads,<ref name="oac1">{{Cite web |date=2017-09-21 |title=LS Engines 101: An Introductory Overview of the Gen III/IV LS Engine Family |url=https://www.onallcylinders.com/2017/09/21/ls-engines-101-introductory-overview-gen-iiiiv-ls-engine-family/ |access-date=2023-03-23 |work=[[Summit Racing Equipment|OnAllCylinders]] |language=en |author=Staff |archive-date=September 24, 2024 |archive-url=https://web.archive.org/web/20240924064328/https://www.onallcylinders.com/2017/09/21/ls-engines-101-introductory-overview-gen-iiiiv-ls-engine-family/ |url-status=live }}</ref> except for the 1999 and 2000 [[model year]] of the LQ4, which were cast iron.<ref>{{Cite web |last=Garbe |first=Eric |date=2022-01-21 |title=A Guide to LS Cylinder Heads |url=http://www.enginebuildermag.com/2022/01/a-guide-to-ls-cylinder-heads/ |access-date=2023-03-23 |website=Engine Builder Magazine |language=en-US |archive-date=March 20, 2023 |archive-url=https://web.archive.org/web/20230320224245/https://www.enginebuildermag.com/2022/01/a-guide-to-ls-cylinder-heads/ |url-status=live }}</ref> Other modifications to the cylinder heads included a redesign to include significantly better airflow, with evenly spaced exhaust and intake [[Poppet valve|valves]].<ref name="leg" /><ref name=":4" /> A deeper engine skirt meant that the third and following generations were slightly larger than its predecessors; the deeper skirts strengthened the block and improved rigidity. A deep engine skirt refers to an engine block which extends below the centerline position of the crankshaft within the engine.<ref>{{Cite web |date=1998-01-02 |title=Cylinder Block - Building, Inspecting - Tech - Hot Rod Magazine |url=https://www.motortrend.com/how-to/building-a-cylinder-block/ |access-date=2023-03-23 |website=MotorTrend |language=en}}</ref> Another feature across all generations was the {{cvt|4.4|in|mm|sigfig=3}} [[bore spacing]] and pushrods, the former of which is also in use in the [[Chevrolet Gemini small-block engine]].<ref>{{Cite web |date=2021-10-26 |title=Flat-Plane Crank DOHC LT6 to Power the 2023 Corvette Z06! Details and Specs |url=https://www.motortrend.com/how-to/lt6-engine-2023-corvette-z06-details/ |access-date=2023-03-23 |website=MotorTrend |language=en |archive-date=October 27, 2021 |archive-url=https://web.archive.org/web/20211027132036/https://www.motortrend.com/how-to/lt6-engine-2023-corvette-z06-details/ |url-status=live }}</ref> The use of aluminum allowed for further weight reduction; the 1997 LS1 was almost {{cvt|100|lbs|kg|sigfig=2}} lighter than previous cast-iron small-block iterations.<ref name=":4" /> GM also made extensive use of economies of scale for the LS: with the exception of the 4.8L and 7.0L engines, all variants used the same 3.622" stroke (with most of those variants using the same basic crankshaft casting), the 4.8L and 5.3L variants utilized the same block casting, and several variants used the same length connecting rod.<ref>2022 Chevrolet Performance catalog: The LS/LT Engine Family Tree</ref>
Other modifications include long runner intake manifolds, [[Powder metallurgy|powder-forged]] connecting rods and the introduction of six-bolt [[main bearing]]s (as opposed to two or four on the previous generations). Long runner intake manifolds in the LS series increases the airflow into the cylinders at low revolutions, increasing [[torque]] production at lower revolutions.<ref>{{cite magazine|magazine=Engine Builder Magazine|title=LS Intake Manifolds|first=Eric|last=Gabe|date=Jan 26, 2023|access-date=February 5, 2025|url=https://www.enginebuildermag.com/2023/01/ls-intake-manifolds/}}</ref> Truck applications of the LS engine have even longer intake manifolds, being approximately {{cvt|3|in|mm|sigfig=2}} taller than passenger car manifolds.<ref>{{cite book|title=How to Build LS Gen IV Performance on the Dyno: Optimal Parts Combos for Maximum Horsepower|isbn=978-1613253403|first=Richard|last=Holdener|date=2017|publisher=CarTech|___location=[[Forest Lake, MN]]|page=9}}</ref> Most engines were also fitted with [[hypereutectic piston]]s,<ref name=hr/> replacing the previous [[Casting (metalworking)|cast]] pistons which were weaker and less thermally stable.<ref>{{cite web|url=https://www.enginebuildermag.com/2005/06/performance-pistons/|work=Engine Builder Magazine|first=Larry|last=Carley|date=June 1, 2005|access-date=February 5, 2025|title=Performance Pistons|archive-date=May 30, 2024|archive-url=https://web.archive.org/web/20240530002301/https://www.enginebuildermag.com/2005/06/performance-pistons/|url-status=live}}</ref>
Powder-forging involves [[sintering]] a specific mixture of metals and non-metals which have been compressed in a [[Machine press|forming press]]. The mixture is then quickly transferred into a traditional die cavity in a [[forging press]] and is pressed once then cooled. Powder-forging is also more cost-effective compared to traditional die forging, reducing the amount of tooling required to trim inconsistencies in hot-forged connecting rods.<ref>{{Cite journal |last=Ashley |first=Steven |date=February 1991 |title=Connecting rods that crack by design |journal=Mechanical Engineering |publisher=[[American Society of Mechanical Engineers]] |volume=113 |issue=2 |pages=54 |issn=0025-6501 |via=[[Gale OneFile]]}}</ref> Stronger than the forged steel connecting rods of the previous two generations, powder-forged connecting rods have been fitted to every LS and LT engine except for the LS7.<ref>{{Cite web |title=Everything You Wanted to Know About the GM LS Engine Family |url=https://auto.jepistons.com/blog/everything-you-wanted-to-know-about-the-gm-ls-engine-family |access-date=2023-03-30 |website=auto.jepistons.com |date=September 10, 2022 |language=en |archive-date=April 1, 2023 |archive-url=https://web.archive.org/web/20230401020024/https://auto.jepistons.com/blog/everything-you-wanted-to-know-about-the-gm-ls-engine-family |url-status=live }}</ref>
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