This month, we peak inside an SHP short-block and then add a Dart top-end kit to see what kind of power the potent small-block could make on the engine dyno. The short-block was upgraded with a few options, including the larger 4.125-inch bore and piston coatings. Dart utilizes a 3.750-inch crank and when combined with the aforementioned bore size, the engine yields 400 cubes. The crank was upgraded to a forged 4340 steel unit. The base crank is a cast-steel piece. The rods in this test engine are the optional forged H-beam rods, and they swing upgraded forged pistons. Dart's standard SHP short-block and high-performance engines come standard with 4.000-inch bores and a 3.750-inch cast-steel crank for 377ci of fury.
Moving to the top of the engine, Dart had a custom grind camshaft for this application, but kept the hydraulic roller stick on the mild side. The lobes lift open the valves to a maximum of 0.540-inch on both the intake and exhaust side. Duration is listed as 236/242 at 0.050-inch lift. Due to the street nature of this engine, the shop decided to keep the idle smooth and even-a 110-degree lobe separation angle was used to accomplish that task. A popular cam for the SHP combination has been a hydraulic roller stick with 0.480/0.480-inch lift and 230/230 at 0.050-inch specs. This cam will produce about 20 less horsepower than the larger stick in the engine featured here.
The hydraulic roller cam opens and closes 2.02/1.60 valves in Dart Pro1 180cc heads. "The 180 head makes the best power on this engine package. We tried the 200 and 215, but the cam is little. The 180s work much better," commented Tony McAfee, engine builder at Dart. The intake manifold is a dual-plane Dart unit and the team used a Demon 650 for dyno testing. A 1/2-inch spacer under the carb produced the best results on the engine.
Dyno testing of this simple combination resulted in an impressive 525hp and 524 lb-ft of torque. It's a great alternative for the person who wants big power and doesn't want to go through the trouble and expense of using LS-engine.
Recession or no recession-horsepower will always be cool.
DART SHP Build Prices & OptionsNote: These prices are full retail, so typicalstreet prices may be a bit lower.SHP block - $1,532372 CI short block - $2,975400 CI short block - $3,395Upgrade/Forged crank +$600Upgrade/Forged pistons +$425Upgrade/H-beam rods +$275Coating/Thermal barrier piston tops +$232 (set of 8)Coating/Anti-friction piston skirts +$148 (set of 8)Top end kit - Pro1 aluminum heads, dual plane manifold,chrome valve covers- $1,895
Dyno GraphEngine: Dart SHPSize: 400.9ci (4.125x3.750)Compression: 9.5:1Carburetor: Demon 650 with1/2-inch spacer