Page 97 of 2009 Performance Parts by GM Parts Direct

chevy ls series the ls engine family tree everything you wanted to know about gm s 21st-century small-block but were afraid to ask ls heritage the engine family commonly called the ls series debuted in 1997 general motors called it the gen iii small-block with the iron-block versions in trucks and the all-aluminum ls1 version introduced in the then-new c5 corvette a year later the ls1 replaced the lt1 small-block in camaros and firebirds the ls1 displaced 5.7 liters similar to the previous-generation small-block but the cubic-inch measurement differed slightly 346 for the ls1 versus the traditional 350 cubes in 1999 the gen iii platform spawned the higher-performance ls6 that was standard in the corvette z06 in 2005 the gen iv branch of the ls family was born differing from the gen iii with cast-in provisions for fuel-saving cylinder deactivation larger displacements and revised camshaft sensing the performance versions of the gen iv include the ls2 ls3 ls7 and ls9 supercharged gm has continued to refer to its modern v-8 engine family as gen iii and gen iv but to the enthusiasts who quickly grasped the tremendous performance potential of the engines every engine based on the platform is nicknamed ls the range of production engines from the ls platform is wide on the truck side iron-block engines have included 4.8l and 5.3l versions as well as all-aluminum 6.0l and 6.2l premium engines car engines include 5.3l 5.7l 6.0l 6.2l and 7 displacements­including some configured for front-wheel-drive .0l gen iii/iv small-block crate engines part number 19165628 17801267 17801268 19165484 discontinued description ls327/327 ls1 ls6 ls2 liters 5.3 5.7 5.7 6.0 6.0 6.2 6.2 6.2 6.2 6.2 6.2 6.2 7.0 cid 327 346 346 364 364 376 376 376 376 376 376 376 427 hp 327 350 405 400 440 430 485 515 430 556 638 525 505 torque 347 365 395 400 404 424 475 469 424 551 604 471 470 bore 3.780 3.898 3.898 4.000 4.000 4.065 4.065 4.065 4.065 4.065 4.065 4.065 4.125 stroke 3.622 3.622 3.622 3.622 3.622 3.622 3.622 3.622 3.622 3.622 3.622 3.622 4.000 ls2 in2005,thels26.0l364cubicinchesengineandthegenivdesignchanges debuted in gm performance vehicles it was offered in the corvette gto and even the heritage-styled ssr roadster its larger displacement brought greater power the ls2 is one of the most adaptable engines as ls1 ls6 ls3 and l92 cylinder heads work well on it chevy ls series 17802134 discontinued ls364/440 12611022 19171224 19171225 19201992 19211978 19201990 19171821 19165058 l99 ls376/480 ls376/515 ls3 lsa ls9 ct525 ls7 ls3/l99 introduced on the 2008 corvette the ls3 brought ls base performance to an unprecedentedlevel:430horsepowerfrom6.2l376cubic-inches makingit the most powerful base corvette engine in history the ls3 block not only has larger bores than the ls2 but a strengthened casting to support more powerful 6.2l engines the ls3 is offered in the pontiac g8 gxp and is also the standard v-8 engine in the new 2010 camaro ss the l99 version is equipped with gm s fuel-saving active fuel management cylinder deactivation system and is standard on 2010 camaro ss models equipped with an automatic transmission lsa the baby brother to the ls9 this supercharged 6.2l engine is standard in the 2009 cadillac cts-v it is built with several differences when compared to the ls9 including hypereutectic pistons versus the ls9 s forged pistons and a smaller 1.9l supercharger the lsa also has a different charge-cooler design on top of the supercharger horsepower is rated at 556 in the super-quick caddy non-production cylinder blocks c5r developed for the factory-backed corvette racing program the c5r cylinder block has been manufactured in comparatively small quantities since 2000 they are manufactured with a unique aluminum alloy for greater strength and undergo a variety of specialized machining and inspection processes including hipping to increase strength and x-raying that ensures against unacceptable porosity a siameseboredesignwith4.117-inchfinishedboresenables7 .0l427cubic-inch displacements the c5r uses billet steel main caps with premium 4340 fasteners racing-quality head studs are also included all ls series heads will work withthec5rblock,butmaximumperformancedependsonmaximumairflow lsx bowtie block standard and tall-deck introduced in 2007 the lsx bowtie block is a durable and affordable cast-iron casting that was designed to support extremehigh-performancecombinations,includingprovisionsforsix-bolts-percylinderheadfastening.ithasasiameseboredesignwith3.99 boresthatmust befinishedto4.00inchesorlarger witha4.25-inchmaximumbore.maximum stroke can reach 4.25 inches but rotating assembly interference on the cylinder mustbetakenintoaccountforstrokesgreaterthan4.125inches;heavymetalis required for crankshaft balancing of larger-stroke combinations standard versions feature decks 0.020-inch taller than ls production blocks with the tall-deck version manufactured with a 9.70-inch semi-finished deck height the oiling system is a true priority-main system and all ls small-block heads work with the engine crankshafts generally ls crankshafts are similar in design with identical 2.10-inch rod and 2.65-inch main journal sizes and a common rear main seal all production ls enginesuseironcrankshaftsexceptthels7 ,ls9andlsa;theyuseforged steelcranks4.00-inchstrokeonthels7;3.62-inchstrokeonthels9andlsa the crankshaft sensing function of the distributorless ignition system depends on reading the toothed reluctor wheel on the crankshaft early ls engines mostlyused24-toothwheelsandupgradedafewyearsagoto58-toothalso knownas58xwheels.whenbuildinganlsengine,itisimperativethatthe correct reluctor wheel is used with the compatible crankshaft position sensor and ignition controller the crankshafts are mostly interchangeable but the snouts on ls7 and ls9 crankshaftsareapproximatelyone-inchlongertoaccommodatetheirtwo-stage oil pumps that work with the engines dry-sump oiling systems these forged crankshafts can be used on wet-sump engines by using a few specific componentsand/ormodificationsseepage218 the easiest way to put a forged stroker crankshaft in your ls engine is using gm performance parts new lsx crankshafts which are available in four stroke sizes up to 4.125 inches they feature the standard-length snout and can be used without modification on most engines ls7 and ls9 crankshafts can be used but require special components and/or modifications to their snouts to accommodate standard wet-sump oiling systems gen iii versus gen iv despite some significant differences between gen iii and gen iv cylinder blocks all ls engines share common traits that include · · · · · · · 4.40 borecentersliketheoriginalsmall-block six-bolt,cross-boltedmainbearingcaps centermainthrustbearing 9.24 deckheight four-bolt-per-cylinderheadboltpattern 0.842 lifterbores distributorless,coil-near-plugignitionsystem ls9 the most powerful production engine ever from gm the ls9 is the 6.2l supercharged and charge-cooled engine of the corvette zr1 it is rated at an astonishing 638 horsepower the ls9 uses the strengthened 6.2l block with stronger roto-castcylinderheadsandasixth-generation2.3lroots-typesupercharger like the ls7 it uses a dry-sump oiling system it is the ultimate production ls engine.itisbuiltbyhandatthegmperformancebuildcenterinwixom,mich ls7 a legend in its own time the ls7 is the standard engine in the corvette z06 andits7 .0ldisplacement427cubicinchesmakesitthelargestsmallblock engine offered in a production car unlike ls1/ls6 ls2 and ls3 engines the ls7 uses a siamese-bore cylinder block design required for its big 4.125-inch bores competition-proven heads and lightweight components such as titanium rods and intake valves make the ls7 a street-tuned racing engine with 505 horsepower ls7 engines are built by hand at the gm performance build center inwixom,mich the most distinguishing differences between gen ii and gen iv cylinder blocksarelargerboresonsomeengines differentcamshaftpositionsensor locations front timing cover area on gen iv blocks and top-rear position on gen iii blocks and on most gen iv blocks cast-in provisions for gm s active fuel management cylinder deactivation system thereisgreatinterchangeabilitybetweenalllsenginesincludingbetween geniiiandgenivversions cylinderheads,crankshafts,intakemanifoldsand morecanbemixedandmatched butthedevilisinthedetails.notevery head matches every intake manifold and not every crankshaft works with every engine combination will handzel s how to build high-performance chevy ls1/ls6v-8s p/n88958786isagreatreferencesourcethatoutlinesthemore specific differences and interchangeability among gen iii-based engines gen iii and gen iv vortec truck engines although performance car engines have typically carried ls designations truck engines built on this platform have been dubbed vortec they are generally distinguished by iron cylinder blocks and smaller displacements than car engines interestingly a 5.7l vortec ls engine has never been offered here s a quick rundown of the previous and current-production ls truck engines · 4.8l thesmallest-displacementlsengine293cubic-inches ituses an iron block with 3.78-inch bores and aluminum heads · 5.3l themostcommonlstruckengine,itusesthesameironblock with 3.78-inch bores as the 4.8l but with a larger 3.62-inch stroke crankshaft327cubicinches laterversionsareequippedforactive fuel management manufactured with iron and aluminum cylinder blocks · 6.0l usedprimarilyin¾-tonandone-tontrucks,the6.0l364cubicinchesusesanironblockly6oraluminumblockl76andaluminum heads,withprovisionsforactivefuelmanagement;someequipped with variable valve timing · 6.2l commonlyreferredtobyitsl92enginecode,the6.2l376 cubic-inchesengineusesanaluminumblockandheads,andincorporates advanced technology including variable valve timing the l92 is used primarily as a high-performance engine for the cadillac escalade andgmcyukondenali connecting rods ls connecting rods are very similar and mostly interchangeable most are made of powdered metal while the ls7 and ls9 rods are forged titanium rods lengths are similar too at 6.098-inch for 5.3l 5.7l 6.0l and 6.2l engines the 4.8l engine uses 6.275-inch rods and the ls7 uses 6.067-inch rods since 2006 lsrodsusebushedsmallends.also,ls6rodsboltsp/n11600158offera strength-enhancing upgrade to pre-2000 engines finally the ls7 and ls9 rods have a slightly different size than other ls rods requiring a unique bearing p/n89017811 special note about crankshaft bolt patterns allpre-2009crankshaftsutilizea6-boltflywheel/flexplateboltpattern.starting in 2009 the lsa utilizes an 8-bolt pattern and the ls9 utilizes a unique 9-bolt pattern all lsx high performance crankshafts utilize the 8-bolt pattern common to the lsa ls4 perhaps the most unique application of the ls engine in a car the ls4 is a 5.3l versionusedinthefront-wheel-drivechevroletimpalassandpontiacgrandprix gxp the ls4 has an aluminum block and unique low-profile front-end accessory system including a flattened water pump to accommodate the transverse mountingpositionwithintheimpalaandgrandprix.itisratedat303horsepower and 323 lb-ft of torque pistons thels9istheonlyproductionlsenginewithforgedaluminumpistons;allthe otherenginesusehypereutecticcastaluminumalloypistons variedmostly by diameter to accommodate various bore sizes ls cast pistons shouldn t beusedonapplicationsgreaterthanapproximately550horsepower.thels7 piston s inner bracing and larger pin diameter require the use of the matching ls7connectingrod.thesameistrueforls9pistons;theyrequiretheuseofls9 connecting rods ls1/ls6 ls15.7l346-cu-inengineswereproducedbetweenthe1997and2004model yearsintheunitedstatescorvette,camaro,firebirdandgtoandstretching into2005inothermarketsprimarilyaustralia thels6wasintroducedin2001 in the corvette z06 and was manufactured through 2005 when it also was found in the cadillac cts-v the ls1 and ls6 share a 5.7l displacement but the ls6 production engine uses a unique block casting with enhanced strength greater bay-to-bay breathing capability and other minor differences the heads intake manifolds and camshaft also are unique ls6 parts 190 buy online at www.gmperformanceparts.com buy online at www.gmperformanceparts.com 191

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