The Build Philosophy

Written by Richard Holdener

Dedicated engine builds are typically optimized for a single configuration. Naturally aspirated combinations differ from nitrous setups in cylinder head selection, cam timing, and compression ratio. Supercharged engines typically run lower static compression - effective under boost, but a compromise off-boost.

This 496ci big-block was built differently. The goal was a single combination that performed well across all three configurations: naturally aspirated, nitrous, and supercharged. For a street or street/strip engine where the owner's plans may evolve, a multipurpose foundation offers more long-term value than a dedicated setup.

Two conditions had to be met: internal strength sufficient to handle any power-adder, and a naturally aspirated baseline strong enough to respond well to both nitrous and boost.

The Short-Block

The foundation started with a Gen V four-bolt block machined to accept a Scat 4.25-inch, 4340 forged-steel stroker crank. Carrillo Bullet-series rods - manufactured from 4330 modified forgings with WMC H-11 tool steel fasteners and balanced to within 1.0 gram - connected to 4.31-inch forged CP pistons. The 24cc-dome pistons produced a static compression ratio of 10.5:1 using 2618 alloy construction with dual-forced pin oilers and chromoly wristpins. That compression was intentional: high enough to contribute meaningful naturally aspirated power, low enough to tolerate boost.

The Gen V four-bolt block, machined for the Scat 4.25-inch forged stroker crank.

Scat crank paired with Carrillo Bullet-series rods and forged CP pistons.

The forged rotating assembly combined with the four-bolt block to create a short-block rated for any power-adder configuration.

CP small-dome pistons with generous valve reliefs - selected for the compression balance between off-boost power and forced induction tolerance.

Cam, Heads, and Induction

A Comp Cams 300BR-14 blower cam was selected - a solid roller grind with 0.652/0.652-inch lift, a 255/262-degree duration split at .050, and 114-degree LSA. This profile was chosen for supercharger compatibility while maintaining strong performance in naturally aspirated and nitrous configurations. Comp Cams also supplied solid roller lifters, paired with hardened pushrods and Crane 1.73:1 (BBF) Gold roller rockers.

Cylinder heads were CNC-ported ProMaxx aluminum units with 340cc intake ports flowing 412 cfm at 0.900 lift, a 2.30/1.88 stainless back-cut and swirl-polished valve package, and 122cc combustion chambers. These heads had previously supported over 800 hp on a 572 stroker - more than adequate for the 496.

Induction was an Edelbrock single-plane Super Victor intake paired with a Holley 1050 Ultra Dominator carburetor. ProMaxx heads were secured with ARP head bolts and Fel-Pro MLS head gaskets, with block and head deck surfaces finished to MLS specifications.

Comp Cams 300BR-14 blower cam: 0.652/0.652-inch lift, 255/262-degree duration split at .050, 114-degree LSA.

Adjustable double-roller timing chain with nylon cam button for roller cam thrust control.

Bottom end completed with a high-volume oil pump, HD intermediate shaft, Milodon pickup, and ARP oil-pump stud.

CNC-ported ProMaxx aluminum heads: 340cc intake ports, 412 cfm at 0.900 lift, 122cc chambers.

The 121cc combustion chambers with 2.30/1.88 stainless valve package produced 10.5:1 static compression with the dome pistons.

Fel-Pro MLS head gaskets - rated for power-adder applications with properly finished deck surfaces.

Triple spring package supporting roller cams to 0.900-inch lift, actuated by Crane 1.73:1 (BBF) Gold roller rockers.

Edelbrock single-plane Super Victor intake, designed for a 4500-series carburetor.

Holley 1050 Ultra Dominator carburetor - dialled in within one jet change of the baseline calibration.

Naturally Aspirated Baseline

After break-in cycles with Lucas break-in oil, the combination was tuned. The Holley carb required a single jet change. Timing sweeps up to 40 degrees found the optimum at 37 degrees. The result: 677 hp at 6,400 rpm and 591 lb-ft of torque at 5,300 rpm.

Subsystems included a billet MSD distributor, an SFI-approved Speedmaster damper, fabricated Speedmaster valve covers, and a complete oiling system.

Speedmaster neutral damper and fabricated valve covers installed. Naturally aspirated result: 677 hp at 6,400 rpm, 591 lb-ft of torque at 5,300 rpm.

Configuration Two: Nitrous

An NOS Cheater nitrous system was installed - a carbureted plate system with dual solenoids, adjustable jetting, a 10-pound bottle, and all mounting hardware. Jetting was set for an additional 150 hp. The bottle was heated to 92 degrees for optimum 900+ psi pressure.

Total timing was pulled back 4 degrees (against a recommended 6), and a splash of 100-octane race fuel was blended with the 91-octane base for additional margin. The result: 859 hp at 6,300 rpm and 769 lb-ft of torque at 5,700 rpm. The 150 hp jetting delivered 182 hp of actual gain with careful tuning.

NOS Cheater nitrous system - complete kit rated for up to 250 hp of additional output.

Holley Dominator removed to install longer studs and the nitrous plate on the Edelbrock intake.

Dual spray bars for simultaneous nitrous and fuel injection.

Solenoids with adjustable jetting - configured for a 150 hp shot.

Bottle heated to 92 degrees for optimum flow - producing over 900 psi bottle pressure.

Nitrous-injected result: 859 hp at 6,300 rpm, 769 lb-ft of torque at 5,700 rpm.

Configuration Three: Supercharged

The carbureted induction system was replaced with fuel injection - an Edelbrock 454-R intake converted for EFI use, a Wilson billet elbow with 105mm throttle body, and a Holley EFI management system. The carburetor's incidental charge cooling was replaced by a ProCharger air-to-water intercooler, which dropped charge temperatures by over 80 degrees at 11 psi.

Boost came from a ProCharger F-1A-94 centrifugal supercharger. Testing used the largest supplied blower pulley (4.50-inch) paired with the ProCharger crank pulley - the lowest available boost configuration. At a peak of 11.2 psi, the supercharged 496 produced 1,144 hp at 6,500 rpm and 925 lb-ft of torque at 6,500 rpm.

The torque peak had just been reached and horsepower was still climbing at over 20 hp per 100 rpm - a clear indication of additional capacity in both the supercharger and the combination.

Edelbrock 454-R intake converted for EFI, with Wilson billet elbow and 105mm throttle body.

ProCharger F-1A-94 centrifugal supercharger - rated for over 1,200 hp.

Multiple blower pulley sizes supplied by ProCharger for boost adjustment against the 10-rib crank pulley.

Testing used the largest 4.50-inch blower pulley - the mildest configuration available, with significant boost left in reserve.

ProCharger air-to-water intercooler - reducing charge temperatures by over 80 degrees at 11 psi.

Supercharged result: 1,144 hp at 6,500 rpm, 925 lb-ft of torque at 6,500 rpm - at just 11.2 psi with the mildest pulley configuration.

The Full Picture

Naturally aspirated, the 496 delivered 677 hp and 591 lb-ft. With the NOS Cheater system jetted for 150 hp, actual output reached 859 hp and 769 lb-ft - a 182 hp gain with additional capacity remaining in the kit. The forged Carrillo rods and CP pistons handled the load without concern.

Under boost, the same combination reached 1,144 hp at just 11.2 psi. With each psi of boost worth approximately 47 hp on this engine, and the ProCharger F-1A-94 capable of substantially more pressure, an estimated 200+ additional horsepower remained available without exceeding the supercharger's operating range.

The principle held across all three configurations: a well-engineered naturally aspirated foundation - with the right compression, head flow, and cam timing - scales predictably with every power-adder applied to it. Build the base right, and the rest follows.