L33 cam swap

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by SAGO, Sep 17, 2013.

  1. SAGO

    SAGO New Member

    I've got a few bolt ons and I want a little more power. I know the L33 is basiclly a LS6 motor from heads, intake, and higher lift cam than other 5.3 motors, and 100lbs lighter aluminum block. Whats everyones thoughts on adding more to this motor... Cam, throttle body, mass flow air sensor...
    Last edited: Sep 17, 2013
  2. TRPLXL2

    TRPLXL2 Epic Member 5+ Years 1000 Posts

    Do more research, a L33 is a 327, an ls6 is a 396. Your missing a couple cubic inches.... J/K

    Ls1 5.7-348 ci
    Ls2 6.0-358 ci

    Cam kit, big bore throttle body, porting intake to match, and maf sensor. $2,000-$3,000 if you do the labor yourself. Good luck!
  3. SAGO

    SAGO New Member

    Here ya go, I found this on GM*powertrain.com.RPO L33 FOR*CHEVROLET*SILVERADO*AND*GMC SIERRAThe 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.

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    I've done my homework brother. Even changing the intake I'll loose bottom end, but gain power from 2000rpm to red.
  4. Sierraowner5.3

    Sierraowner5.3 Epic Member 5+ Years 1000 Posts

    GMs run hot anyways. they peak torque around 4200. do some trans work and itll be a beast at a 20 roll.

  5. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    This is also from the GM powertrain website, the key word is "like", yes the L33 uses components from the LS6 and is constructed like the LS1, but the bore and stroke is actually a 326.

    5.3 L The Vortec 5300 is a V8 truck engine. It is a stroked (by 9 mm) version of the Vortec 4800 and replaced the 5700 L31. Power output is 285-315 hp (223-239 kW) and torque is 335 lbf·ft (454 N·m) to 350 lbf·ft (470 N·m). Displacement is 5.3 L (5,328 cc (325.1 cu in)) from 96.01 mm (3.779") bore and 92.00 mm (3.622") stroke. Another engine variant, the L33, shares the same displacement, but has an aluminum block with cast in cylinder liners, much like the LS1. This allowed a 100 lb weight savings over the standard LM7 model. Other differences were a higher lift cam shaft (0.482" v. 0.456" on both intake & exhaust), higher compression ratio (9.9:1 v. 9.49:1), and used cylinder heads originally designed for the LS6. These differences bumped output: GM rated the engine at 315 hp (235 kW) and 338 lbf·ft (458 N·m). This engine was used only in extended cab, short bed, four-wheel drive vehicles in model years (late) 2005 through (early) 2007.
  6. SAGO

    SAGO New Member

    Has heavy clutches, and a ATS torque converter, oversized tranny cooler. The tranny is tough and chirps the wheels into 2ND with the right tune, and when it down shifts into 1at all the time. I just want more torque with keeping it reliable. It is a daily driver. Roughly 100 miles day.
  7. Sierraowner5.3

    Sierraowner5.3 Epic Member 5+ Years 1000 Posts

    I have a buddy with a 07 extended cab 4x4 chevy (obs) that has a cam, I will talk to him and see what he has in it. He keeps up with my truck fairly easily, and I have the engine and transmission tuned.


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