A Dart Big M iron block was...
A Dart Big M iron block was selected as a foundation for this nitrous gulping engine. The cylinder bores measure 4.600-inch each and when combined with a 4.500-inch stroker crankshaft the displacement comes in at 598 ci.
Organized Street Legal Drag Racing has a profound way of pushing racers thanks to an ever-tightening rulebook and even tougher competitors. It is through those two groups of people that CHP arrived at its latest engine building adventure-a 598ci engine by Pettis Performance. CHP Editor Henry De Los Santos and his longtime racing partner Artis Houston conceived the project as Artis' '71 Nova was falling a step behind in the tough PSCA Wild Street category. This isn't the first collaboration between the two speed freaks; Henry stuffed a different 598 in the Nova back in '06. From there they had refined the nitrous-gulping big-block and the Nova eventually dipped into the 7s with a 7.90 at 176 mph on a set of 275 drag radials.
The rank's competitiveness motivated Henry to go back to the drawing board- along with Pettis Performance and Artis-to develop a 598ci powerplant using what the team had learned with its previous engine and the 540ci bullet before then. On the Outlaw scene, the turbos and superchargers run unrestricted and pretty much dominate many of the popular classes. However, in organized Street Legal drag racing sanctioning bodies-like the NMCA, WCHRA, and PSCA- the power adders are restricted and the tech officials attempt to keep the playing field level between the nitrous, blower, and turbo combinations.

Pettis Performance ensures...

Pettis Performance ensures the block is perfectly decked and indexed for proper deck angles in relation to the line-hone. Jason Pettis said this is a critical procedure so all measurements and adjustments are accurate. A set of 55mm roller cam bearings was also installed.

Once the Dart block is checked...

Once the Dart block is checked and decked, the cylinder bores are enlarged. A dial-gauge is used to locate the center of bore and the cutting process begins. These bores are opened up to 4.600 inches.
The Wild Street rules offer various weight breaks for nitrous-enhanced big-block engines. While the rules tend to change; at the time, the California-based racers opted to stay with the 598-cid, where the Nova could run at a minimum of 3,325 pounds. If a smaller displacement (up to 550ci) was utilized, the car could have run the scales at 3,175-pounds. Adding a sheetmetal intake, like on this engine, carried an additional 50-pound penalty, and if you ran anything but conventional heads with plus or minus 3 degree valve angle, they would have to add another 50 pounds. Instead, they decided take advantage of the weight break and stick with a conventional set of heads, namely the Edelbrock Victor 24-degree units. Keep in mind that this sounds great in theory; however, it wasn't until recently that they were able to make use of these weight breaks and go from well over 3,400 pounds to 3,330 with the addition of a one-piece front clip and Lexan windows.
Still, don't let the conventional heads and mild cubes (for today's racing standards anyway) fool ya; this engine is capable of serious power. Without getting too far ahead of ourselves; this engine made over 1,100 hp-without the Induction Solutions (Steve Johnson) three-stage nitrous system turned on. It's a lot of power for the faint of heart but a great starting point in the Wild Street game. Since '06, the class record has jumped down to a 7.66 at 184 mph, which was recorded by Chris Groves in his ProCharger-powered Mustang LX coupe. "We also went with the bigger motor to keep up with the blower and turbo combinations," commented Henry and one look at the event results shows the blower and turbo combos are flat-out flying.

Once the bores are enlarged,...

Once the bores are enlarged, Pettis hones the block. A BHJ plate is torqued down to simulate the cylinder head tension. Pettis even uses a pair of head gaskets during the process.

The short-block is assembled...

The short-block is assembled so Pettis can check the block clearances, specifically where it needs to be notched to clear the long-stroke crankshaft and GRP aluminum rods. The Comp Cams camshaft and Jesel belt-drive are also installed to make sure all rotating parts move freely.

Pettis marked the area of...

Pettis marked the area of contact on the block and removed as little material as necessary.