L33 5.3 400hp+ build recipe @ $1750.00 cost

[Cobalt964ruf]

first, there are many ways to do this, na, boost, different cam and heads, bigger displacement, so on. but this one has worked for me. also please first go to www.carcraft.com and look at the 5.3 cam article. they took a stock lm7 truck 5.3 iron block motor and put a ls2 cam and springs and made 403chp. so a L33 aluminum 5.3 with 243 heads, flat top pistons and 9.9 to 1 compression with a ls2 cam/springs, ls6 intake, headers, tb, and a tune will make that and then some....

again there are many ways to do this, but this is a proven low buck recipe that is repeatable by many and hopefully I can help others with this.

my experience; L33 5.3 aluminum longblock/243 heads with 8k miles was 600.00. 12k mile oem ls2 cam and springs 150.00, ls6 intake 300.00, ebay .080 pushrods 85.00, arp rod bolts 90.00, ebay 8740 headstuds 68.00, oem gaskets and seals 190.00, lq9 injectors 50.00, 78mm ported oem throttle body 65.00, truck 85mm maf 35.00, ebay stainless headers 195.00, made my own stand alone harness 0.00, hptuners setup 600.00. easy 400crankhp, likely more like 440-450chp. but who cares since it is in a 2280lb car with a 5 speed. @$1700.00 before hptuners not bad cost wise, runs on pump gas and very repeatable by many.

this is on stock compression 243 heads, for another small bump in hp you could jump the compression to match the 706/862 heads 62cc chambers.

again in no way is this the only way or the best way, but I have built it and it works and runs like a superbike on four wheels.

post script; what gm says the l33 is.

The Vortec 5300, or LM7/L59/LM4/L33, is a V8 truck engine. It is a longer-stroked (by 9 mm) version of the Vortec 4800 and replaced the 5700 L31. L59 denoted a flexible fuel version of the standard fuel LM7 engine. Displacement is 5.3 L (5,328 cc (325.1 cu in)) from 96.01 mm 3.78-inch (96 mm) bore and 92.00 mm (3.6 in) stroke 3.622-inch (92.0 mm) stroke. Vortec 5300s are built in St. Catharines, Ontario and Romulus, Michigan.

The Gen III Vortec 5300 is available in a new lighter, higher output variant optional on some 2005 Silverados and Sierras. RPO L33 will be introduced in short bed, extended cab versions of these pickups. The L33 features an aluminum engine block, new cylinder heads and a high-lift cam. Torque will increase, and horsepower is expected to exceed 300 in final production trim.

One of the L33’s distinguishing features is its engine block. As with the 2004 LM4 Vortec 5300, the L33’s foundation is a cast-aluminum block with pressed-in iron cylinder liners, similar to the block used for GM Powertrain’s LS1 and LS6 car V-8s. The L33 block is exceptionally light; as a result, a fully dressed L33 is 100 pounds lighter than cast iron-block Vortec 5300s (RPOs LM7 and L59).

The L33 takes its cylinder heads from the LS6. Originally developed for the Z06 Corvette, these heads improve airflow in and out of the engine. With their pent-roof combustions chambers and new flat top pistons (the pistons in other Gen III Vortec 5300s have a slight sump in the piston deck), the L33’s compression ratio increases from 9.5:1 to 9.9:1. This increase improves the engine’s volumetric efficiency yet still allows it to achieve full power with regular grade gasoline.

Finally, the L33 is equipped with a higher-lift camshaft. Maximum valve lift increases from 11.6 mm on the LM7 and L59 to 12.5 mm. The new cam and compression ratio are the primary sources of the L33’s increased horsepower.

The L33 camshaft and cylinder heads were developed in conjunction with the new Gen IV Vortec 5300 (RPO LH6). The design objective was more horsepower for customers who need it, without requiring a step up to the Vortec 6000 (and an increase in operational costs). RPO L33 expands GM Powertrain’s lineup of Vortec V8s and gives GM’s truck customers even more flexibility and choice.

The L33 Vortec 5300 will be built at Powertrain’s Romulus, Mich., engine plant. With its introduction, Powertrain will cease production of Vortec 5300 RPO LM4. The Buick Rainier, Chevrolet Trailblazer EXT and GMC Envoy XL, previously equipped with the LM4, will now be powered by the Gen IV Vortec 5300 with Displacement on Demand. The 2005 Chevrolet SSR will be powered by the new LS2 truck V-8.