1700 HP Procharged LSX Engine

by John Baechtel
Scoggin-Dickey Parts Center (SDPC) has been a national go-to source of GM performance parts for many, many decades. It is a family owned business with  two million square feet of warehouse space in Lubbock Texas bulging to the seams with over 300,000 part numbers for GM racing and high-performance enthusiasts. The SDPC Raceshop is a fully equipped facility capable of building modified GM crate engines and mild to wild racing engines to meet every possible customer requirement. One of its latest creations is this Procharger boosted, 400 cubic inch LSX race engine for drag racer Jason Enfinger. It boasts 1600 horsepower running 100% race fuel down low and transitioning to 100% methanol at higher boost levels.
The engine goes in a bracket racing dragster where Jason has already been a consistent winner at high dollar bracket races with a 12oo horsepower big block Chevy. The goal here is to achieve a 4.20 second or better eighth mile with a calmer, more consistent car for extended usage. The big block generated 0.925 sixty foot times  but it was almost too aggressive off the starting line. The new car uses a Powerglide and a 7000 stall converter. The management system is setup to take out timing in low gear to calm the chassis down and then feed the timing back in as boost rises and the methanol fuel turns on. A more powerful, but calmer car should generate more consistency and thus more wins and a longer service life for the engine. Jason was also seeking a more cost efficient way of racing. The normally aspirated big block would cost about $45,000 and require a refresh after about 250 passes. That could often add an additional $15-20,000 expense each time. This nearly two year project was undertaken to reduce those costs as it is comparatively expensive to build the LSX, but much cheaper to freshen it over longer intervals, because it tolerates the boost well on the methanol.
The SDPC race engine is an exercise in technical expertise with its ability to blend from race gas to methanol on the fly as the engine management system determines the tip over range based on boost with timing adjustments. It also demonstrates the high level of performance available from the SDPC Race Shop.

The GM standard deck LSX block available through SDPC under PN-19417351 features the following specs.

3.880" finished siamese cylinder bores
9.260" semi-finished deck height
Capable of 364-482 cubic inch displacements
CNC-Machined Cast Iron Block
True Priority Main Oiling
6-head bolts per cylinder
Standard 4.400" bore spacing
Extra thick siamese cylinder bores
Semi-finished machined thicker decks
LS7 style 6-bolt dowel located billet main caps

The cylinder block also offers extra thick siamese cylinder bores, semi-finished machined thicker decks, LS7 style 6-bolt dowel located billet main caps, and Wet sump and dry sump oiling capabilities. It features production-style deep skirt head bolt holes with production bolt hole and thread sizes. In this case the main studs are 7/16-inch.  Production exterior accessory mounting provisions include front motor plate mounting holes. There is added material around the cam bearings and this block was machined to accept 55mm roller cam bearings which means no pressurized oiling to the cam bearings and the availability of more oil for priority oiling to the crank. It accommodates all LS oil pans and oil pumps and has a provision for external oil pump feed at rear of block. The main webs are scalloped to provide bay to bay breathing at higher horsepower levels. All in all, a solid foundation for a high horsepower applications.
The cylinder heads for this combination are BRODIX LS7, BP BR 7 BS 300, PN-1178105. They incorporate 300cc intake ports flowing 437 CFM through 2.250-inch Ti valves with 8mm stems and Ti retainers with Beadlocks. The exhaust valves are 1.58-inch diameter Inconel also with 8mm stems and Ti Retainers and Beadlocks. The ports are fully CNC'd as are the 72cc chambers which are blended and prepped with a competition valve job.
The intake manifold is a custom piece from Frankenstein Engine Dynamics. It sports two injectors per cylinder, one for race gas and one for methanol. The outer fuel rail feeds methanol through Billet Atomizer3 injectors. A second set of  injectors from Fuel Injector Development are positioned in the V behind the runners and meter race gas horizontally across the flow path. This works fine because the fuel demand at this point is lower. Running on gasoline yields better idle quality for engine warmup and staging. The smaller gasoline injectors are easy to control  and funnnction perfectly in that environment. As soon as the engine reaches one half pound of boost, the gas injectors shut off and the methanol injectors turn on. Holley's Dominator EFI management system accommodates a normal fuel table on race gas and a second table allows custom blending from 100% race gas to 100% methanol per user selected parameters for a smooth transition. The advantage is in keeping the oil cleaner from methanol contamination at lower engine speeds and lesser fuel demand. At the smaller 400 cubic inches the engine made 660 horsepower on race gas and 680 with the methanol added. The gas injectors in the valley can run 80 lb/hr and the methanol injectors can  move 700 lbs/hr under 30 pounds of boost where 1600-plus horsepower is achieved.
Throttling is managed by a 105mm Wilson Manifolds throttle body, and lubrication is a full dry-sump system using  a Peterson Fluid Systems R4 3 stage pump and a Moroso dry-sump pan.
Car owner Jason Enfinger worked with his friend Joe Pinder to develop the basic hardware to create the race drive setup for the ProCharger. The Race Shop's Kurt Urban then handled the blower installation with the Procharger F-1X-12 centrifugal supercharger that nearly tripled the horsepower output. Urban was required to modify some of the ProCharger mounts and fabricate some small pieces to accommodate the installation. These were necessary to serve the drive systems for the cooling and dry-sump pumps and the alternator.

Cam timing is handled by an Innovators West belt-drive. Kurt found the easiest way to provide a cam position reference signal to the computer was to fabricate an aluminum plate that holds a Holley big block Chevy cam sensor mount. To provide the sensor reference he made his own magnet with a 10-32 stainless mounting screw and drilled the upper cam drive to postilion the magnet where he wanted it. The mounting bracket kit is Holley PN-556-114.

No pictures were taken of the internals, but it is a very robust system with the Bryant billet crank, Callies Enforcer connecting rods and custom Diamond pistons. The 3.75-inch stroke was selected because it makes the crank stronger than a stroker crank due to more material connecting the throws. Crankshaft whipping is ore pronounced on a stroke and is hard on the engine, particularly the number 2 and 4 mains at high power levels. The shorter stroke revs more smoothly and it allows a 1.25 compression height on the pistons which keeps the pin from intruding on the oil ring groove.

The camshaft is a Camonics solid roller shaft speced to provide a relatively quick peak with the blower system rather than a more linear 45 degree ramp up to power. No camshaft numbers were made available. The block is bushed for .937-inch Isky lifters with a .850-inch roller. These are the bused lifter rather than traditional rollers. While the friction tradeoff with rollers is slightly more. it was felt that the bushed lifters were safer for this application.

1600+ HP ProCharger LSX

Scoggin-Dickey Race Shop
Engine Builder              Darrell Burgoon
Blower Setup                 Kurt Urban

Supercharger                     ProCharger F-1X-12
Displacement                    400-cid
Bore/Stroke                       4.125/3.75-inch
Engine Block                      GM LSX, PN-19417351
Crankshaft                          Sonny Bryant Billet
Rods                                     Callies Ultra Enforcer
Pistons                                 Diamond
Camshaft                             Camonics
Rocker Arms                       Crower PN-74164F
Cylinder Heads                  BRODIX LS7,  PN-BP BR 7 BS 300  PN-1178105
Valves                                  2.250 Intake, 1.580 Exhaust
Max Flow                            437 CFM
Intake Manifold                Frankenstein Engine Dynamics
Race Gas Injectors            Fuel Injector Development
Methanol Injectors           Billet Atomizer3
Throttle Body                    Wilson Manifolds 105mm  PN-471105DHB
Engine Management       Holley Dominator System
Cam Sync                           Holley   PN-556-114
Timing Gear                      Innovators West
Balancer                             Innovators West
Dry Sump Pump               Peterson
Oil Pan                                Moroso



Scoggin-Dickey Parts Center Race Shop
5901 TX-327 Spur
Lubbock, TX 79424