Super Chevy Magazine Homepage Super Chevy
Facebook Click here to find out more!

Testing Carb Combos on a Gen III LS Smallblock - Thoroughly Modern Mouse

By Richard Holdener, Photography by Richard Holdener
Small Block Chevy Engine Timing Control Lucas Oil Octane Booster

NA vs. NOS Plate (150-hp)-6.0L LS1
Of course there is no denying the power potential of a good nitrous system. Case in point, the simple NOS plate system installed on this 6.0L LS. With the push of a button, our humble street motor was transformed into a serious strip terror. Adding an extra 150 horsepower required only that we keep the bottle pressure constant (with a bottle warmer) and retard the timing by 4 degrees. We took the liberty of adding a bottle of Lucas Oil octane booster to the 91-octane pump gas (from Rockett Brand) as a hedge against detonation. We figured the 150 hp shot deserved no less. As if the extra 150 horsepower wasn't exciting enough, just wait till you feel the extra 170 lbs- ft. of torque!

While we had both LS1 and LS2 crate motors at our disposal, we decided to build one instead. Since we planned on running some juice to it, we decided forged internals were in order. A call to Lunati netted a steel crank (3.662 stroke) along with the necessary forged rods and pistons designed to fit into our 6.0L truck block. I know what you are thinking, where is all that wonderful weight savings we were raving about earlier? Truth be told, we have big plans for this particular mill, but the same components (or even factory equivalents) could be used at this power level, including the factory 5.7L LS1 or even 6.0L LS2 aluminum blocks. While the 6.0L block shared the 3.662-inch stroke with the smaller 5.7L, the additional displacement came from the larger bore offered in the 6.0L. With the Lunati internals stuffed inside our freshly machined 6.0L block, our short-block was ready for action.

Next up were the cam, heads, and intake. Originally, we wanted to start our testing with a factory LS1, but all we had at our disposal was an LS6 grind. Compared to the stock LS1 cam, the high-performance LS6 grind offered both more lift (0.525 versus 0.500) and duration (204/218 versus 198/209). The reason we wanted to start with the factory cam was that we had a mild Lunati Voodoo cam waiting in the wings. The Lunati Voodoo cam offered 0.531 lift (on both the intake and exhaust) along with a 212/218 duration split. Note that the Lunati specs were only slightly wilder than the factory LS6 cam, but the Voodoo grind offered accelerated ramp rates to further improve power production. Once on the dyno, we planned a direct cam comparison.

With the factory LS6 cam in place, we installed a set of AFR 205 Mongoose heads. The AFR heads featured full CNC porting to enhance flow. Designed for performance street use, these AFR 205s flowed nearly 300 cfm. The AFR heads were topped off with a single-plane intake from GM Performance Parts and a 750 HP carburetor from Holley. Finishing touches on the 6.0L motor included a set of Hooker long-tube (F-body) headers feeding a set of collector extensions and a Meziere electric water pump.

  • Small Block Chevy Engine Timing Control Power Potential
    The lion's share of the power potential goes to CNC-ported intake ports that flow nearly 300 cfm.
    Small Block Chevy Engine Timing Control Power Potential
    The lion's share of the power potential goes to CNC-ported intake ports that flow nearly 3
  • Small Block Chevy Engine Timing Control Lunati Stroker
    With the Lunati stroker assembly and the NOS nitrous system waiting in the wings, we chose a Holley carburetor for our test mule. Our carb of choice was the Holley 750HP.
    Small Block Chevy Engine Timing Control Lunati Stroker
    With the Lunati stroker assembly and the NOS nitrous system waiting in the wings, we chose
  • Small Block Chevy Engine Timing Control Fuel Injection
    Since our LS1 was originally designed for fuel injection and therefore lacked a conventional distributor, we had to come up with a way to control the ignition timing. Luckily, MSD and Edelbrock got together to produce a Timing Control Module designed specifically for carbureted LS1 motors.
    Small Block Chevy Engine Timing Control Fuel Injection
    Since our LS1 was originally designed for fuel injection and therefore lacked a convention
  • Small Block Chevy Engine Timing Control Adjustable Controllers
    Though MSD now offers fully adjustable controllers, this system came with five preprogrammed ignition timing curves to choose from.
    Small Block Chevy Engine Timing Control Adjustable Controllers
    Though MSD now offers fully adjustable controllers, this system came with five preprogramm
  • Small Block Chevy Engine Timing Control Additional Torque
    The next test involved a comparison between the GMPP single-plane intake and this dual-plane Performer RPM from Edelbrock. As expected, the dual-plane was the torque champ, while the single-plane produced the most peak power. Down at 3,200 rpm, the dual-plane offered an additional 44 lbs-ft of torque.
    Small Block Chevy Engine Timing Control Additional Torque
    The next test involved a comparison between the GMPP single-plane intake and this dual-pla
  • Small Block Chevy Engine Timing Control Timing Control Module
    The Edelbrock/MSD Timing Control Module plugged right into the factory LS1 harness and coil packs.
    Small Block Chevy Engine Timing Control Timing Control Module
    The Edelbrock/MSD Timing Control Module plugged right into the factory LS1 harness and coi
  • Small Block Chevy Engine Timing Control Hooker Headers
    Our tester was run with a set of Hooker long-tube (F-body) headers feeding an 18-inch collector extension. Run on the engine dyno with the stock LS6 cam, the carbureted 6.0L produced 467 hp at 6,000 rpm and 457 lbs-ft of torque at 4,800 rpm.
    Small Block Chevy Engine Timing Control Hooker Headers
    Our tester was run with a set of Hooker long-tube (F-body) headers feeding an 18-inch coll
  • Small Block Chevy Engine Timing Control Nitrous System
    The final test involved running a simple plate nitrous system from NOS. Run with 150 hp jetting, the NOS kit upped the peak power of our mild carbureted street motor to an impressive 633 hp. The peak torque was up to an equally impressive 648 lbs-ft.
    Small Block Chevy Engine Timing Control Nitrous System
    The final test involved running a simple plate nitrous system from NOS. Run with 150 hp je
  • Small Block Chevy Engine Timing Control Cam Crank Position Sensor
    The Timing Control Module also included plugs for the factory LS1 cam and crank position sensors.
    Small Block Chevy Engine Timing Control Cam Crank Position Sensor
    The Timing Control Module also included plugs for the factory LS1 cam and crank position s
  • Small Block Chevy Engine Timing Control Lunati Voodoo Cam
    After swapping in the Lunati Voodoo cam, the peak power numbers jumped to 481 hp and 471 lbs-ft of torque. The Voodoo cam offered impressive power everywhere, registering a gain of over 20 lbs-ft. down at 3,200 rpm. Remember, this test was run against the already potent LS6 cam. Compared to the factory LS1 cam, this Lunati grind has been tested to be worth over 30 hp.
    Small Block Chevy Engine Timing Control Lunati Voodoo Cam
    After swapping in the Lunati Voodoo cam, the peak power numbers jumped to 481 hp and 471 l
  • Small Block Chevy Engine Timing Control Engine Dyno Test
SOURCES
AFR Lunati
4770 Lamar Ave.
Memphis
TN  38181
901-365-0950
www.lunaticamshafts.com
Edelbrock
Dept. 5.0
2700 California St.
Torrance
CA  90503
310-781-2222
www.edelbrock.com
MSD Ignition
El Paso
TX
9-15/-857-5200
msdignition.com
GM Performance Parts
www.gmperformanceparts.com
By Richard Holdener
Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!

*Please enter your username

*Please enter your password

*Please enter your comments
Comments:
Not Registered?Signup Here
(1024 character limit)
Super Chevy