$10K Drag Shootout 2: Engine Profile — Team Bigun

The returning Horsepower Wars $10K Drag Shootout Season-One champions, Team Bigun took the first-season win with an LS-powered Fox-body in an impressive performance. As the incumbents with experience, they were saddled with a “disadvantage” this season by being given another Fox-body platform — a 1982 Ford Grenada.

It would have been easy for them just to reproduce the combination that made “Beer Money” so successful, which it seems every other team is trying to do with a turbocharged LS combination. Instead, Team Bigun decided to buck the trend. Not only are they the only team to choose something other than an LS powerplant, but they are also the only team not using a turbocharger.

Still a Chevy In a Ford

When Bigun decided to be different, they REALLY chose to be different. “The big-block nitrous combo was the slowest combination last season, but we saw potential in it,” says Team Bigun leader Eric Yost. In order to get their combination rolling, the team snagged a Chevrolet Mark IV 454 block at the local scrapyard for a cool $150 as the basis on which to build.

Unlike the LS engines, the only original Chevrolet component used in the build was the block itself. To start, the team’s engine builder, Pete Harrell, had the block’s bore opened up .100 inch to 4.350 inches. Once back from the machine shop, Harrell added an ARP four-bolt main stud kit along with a set of King Engine Bearings HP-series bi-metal main bearings.

From there, a Scat Enterprises cast 4.250-inch-stroke crankshaft was dropped into the block for a total displacement of 505 cubes – or about 135 cubic inches larger than the second-largest engine in the competition. A balance of performance and budget, the cast crank should withstand the abuse they are planning to throw at the engine. Wih that in mind, a set of K1 Technologies H-beam rods were bolted to the journals.

Unlike the other teams, Bigun started with just a bare junkyard block. The Mark IV 454 block is a stout piece, but the entire engine had to be built using aftermarket parts, which takes a serious bite out of their budget.

Made from forged 4340 steel, the 6.385-inch rods are fitted with 200,000psi-rated ARP2000 rod bolts to withstand the harsh loads the engine will be subjected to with nitrous. King Engine Bearings HP-series bearings were again used for the rods. The HP-series’ silicon-aluminum construction is designed specifically to withstand the rigors of drag racing used in conjunction with a cast crankshaft.

Attached to the K1 rods are a set of custom 4.350-inch MAHLE pistons. Forged from 2618 aluminum and then treated to MAHLE’s standard Grafal skirt coating, hard-anodized ring lands, and phosphate piston coating, the pistons were designed to withstand hard nitrous use.

While the PROMAXX heads are a solid bang-for-the-buck cylinder head, they come as-cast. Team Bigun engine-builder Pete Harrell put a significant amount of time and effort into porting the runners and chambers to maximize performance.

The block was filled with concrete to help support the cylinders under the high cylinder pressures generated by the nitrous. Also, a set of ARP head studs were utilized to exert as much clamp-load as possible on the cylinder heads to keep them down when the nitrous hits.

Providing the lifeblood to the engine is a Summit Racing high-volume, standard pressure oil pump, along with a Summit Racing street/strip pickup and 7-quart gold zinc-plated oil pan and Proform dipstick. A used SFI balancer of unknown make was used in the build, along with a Summit Racing True Roller double-roller timing set, offering four degrees of camshaft advance or retard, wraps up the Mark IV short-block.

Monster Heads

As the only non-LS engine, Team Bigun’s combination is also the only one to use aftermarket cylinder heads. A sizable budgetary investment, that none of the other teams had to make, Harrell chose to go with a set of PROMAXX Performance Freedom Series cylinder heads

The heads are cast from aluminum and feature an as-cast 320cc intake runner and 119cc chamber volume — all of which got touched by Harrell with a grinder before going on the car.

The Freedom Series heads come assembled with 2.25-inch intake valves, 1.88-inch exhaust valves — with a five-angle valve job — and valvesprings capable of handling up to .700 inch of lift. The heads also come with titanium retainers and 10-degree steel locks.

Using a custom-ground COMP Cams camshaft, Team Bigun went with a little different strategy than everyone else, opting for a mechanical flat-tappet valvetrain. A set of used PBM BBC flat-tappet lifters were sourced to pair with the camshaft, along with a set of Manley .080-inch-wall pushrods.

A Craigslist deal scored a set of used BBC .842-inch roller rockers with poly locks along with a stud girdle for a cool $80, which makes the COMP camshaft the only new piece of hardware in the valvetrain.

Team Bigun's valvetrain is a mix of old and new, with the valvesprings, titanium retainers, and 10-degree locks coming with the heads, while the lifters, pushrods, and rocker arms are used pieces scored through a Craigslist deal.

Spray Away the Competiton

To top off the combination, Harrell opted for a Weiand Track Warrior single-plane intake manifold with a Dominator flange. Of course, that means the team will be running the only carbureted combination in the competition. To fit the Dominator flange, the team chose a Holley Sportsman 1,050cfm Dominator carb.

The monster piece of aluminum comes in almost four pounds lighter than an original Dominator carburetor and features four 2.00-inch throttle bores, 1.69-inch venturi, mechanical secondaries, dual fuel inlets, and fully machined air and fuel passages. Given a choice to run either VP Racing Fuels‘ traditional C16 race gas or the new X85 race-blend ethanol, Bigun went with ol’ reliable: C16. It will not only work well with their carburetor and fuel system but also with their power-adder.

Plumbed into the manifold is a NOS Pro Shot Fogger direct-port nitrous kit. Rated up to 300 additional horsepower with the included jetting, the dual nitrous and fuel solenoids are capable of supplying up to 500 horsepower at the push of a button. However, the team scored a used NOS Launcher nitrous controller, so the giant hit of nitrous can be ramped in and tuned to the track conditions, to not blow the tires off.

To feed the monster carb and the nitrous system’s fuel solenoids, the team scored an old-school used Holley external fuel pump, capable of providing 500 gallons per hour in a drag racing application, for $125. The team is living dangerously, running without fuel filters to save budget, with the fuel supply regulated by a universal Holley 4.5-9psi fuel pressure regulator plumbed with Fragola hoses and fittings.

Not only is Team Bigun’s BBC/nitrous combo the only non-LS and non-turbo entry in the competition, but it is also the largest displacement by a significant amount. Coming in at 505 cubic inches, it is 135 cubic inches larger than the second-largest engine in the competition, and 213 cubes larger than the smallest.

Since there is no ECU in Bigun’s combination, a more traditional ignition setup (compared to the LS) from E3 Spark Plugs is run. E3’s 6-series capacitive-discharge ignition box is used, along with E3’s high-output coil, slip-collar distributor, 8.5mm spiral-core plug wires and E3-33 spark plugs.

Having won last season with the combination every other team is now trying to mimic, Team Bigun’s choice in engine and power-adder is a gamble. Especially considering the nitrous big-block Chevy combination’s performance last season. However, the team is hoping to prove to be a threat, no matter what combination they are running under the hood.

Team Bigun Spec Sheet

Team: Bigun
Engine:  Mark IV big-block Chevy
Total Displacement: 505 cubic inches
Bore x Stroke: 4.350 inches x 4.250 inches
Block: Mark IV 454
Crankshaft: Scat Enterprises Cast 4.250-inch stroke
Main Bearings: King Engine Bearings HP-series
Rod Bearings: King Engine Bearings HP-series
Rods: K1 Technologies H-beam, forged 4340 steel, 6.385 inches
Pistons: MAHLE 4.350-inch forged 2618 aluminum
Rings: Total Seal custom
Oil Pump: Summit Racing high-volume, standard pressure
Oil Pan: Summit Racing gold zinc-plated steel, 7 quart
Timing Set: Summit Racing True Roller double-roller, adjustable
Cylinder Heads: PROMAXX Performance Freedom-Series, 320cc intake, 119cc chamber, assembled
Port Work: Hand ported
Head Gaskets: Unknown
Valves: 2.250-inch intake, 1.880-inch exhaust
Valvesprings: Single spring, capable of .700-inch lift
Locks/Retainers Steel 10-degree lock, titanium retainer
Camshaft: Custom COMP Cams mechanical flat-tappet grind
Lifters: PBM .842 mechanical flat tappet (used)
Rockers: Unknown-make roller rockers with poly locks
Pushrods: Manley Performance .080-inch-wall
Carburetor: Holley Sportsman Dominator, 1,050cfm
Intake Manifold: Weiand Track Warrior, single-plane
Headers: Hooker (used)
Power Adder: NOS Pro Shot Fogger direct-port nitrous system
Nitrous Controller: NOS Launcher (used)
Ignition Box: E3 6-series CDI
Coil: E3 high-output CD coil
Spark Plugs E3-33
Plug Wires E3 8.5mm spiral-core
Fuel Pump: Holley 500gph

About the author

Greg Acosta

Greg has spent fifteen years and counting in automotive publishing, with most of his work having a very technical focus. Always interested in how things work, he enjoys sharing his passion for automotive technology with the reader.
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