Without a doubt, today's latest performance parts improve power, driveability, and efficiency over yesterday's factory or aftermarket offerings. to prove our point with regard to the venerable big-block Chevy, we enlisted the help of joey Diorio. His 454-powered '55 Bel air was your typical mid- '80s street/strip buildup. a diehard Chevy man, joey D has been working on small- and big-blocks since the 1960s. His no-jive-five-five (nj55) is a regular street driver that goes to the strip a few times a year and is equipped with a '70s 454/425hp replacement long-block with rectangular port heads. thousands of these replacement motors were sold during the 1970s and 1980s, and we're gonna show you how to make any big-block better.
We chose five key components to update the big-block. By swapping to today's high-tech parts, we knew the '55 could be a better contender on the ever-tougher streets of Jersey. Our first component of choice went right to the heart of the motor: Lunati's latest in camshaft technology, a Voodoo solid street roller. This solid roller stick will offer added lift, vacuum, efficiency, torque, and horsepower over the flat tappet hydraulic it replaces.
For a comparison as fair as possible, we chose a cam with a similar duration, but because it's a roller, the valve will see over .100-inch more lift. The extra lift will dramatically improve street driveability and torque. In the 454 is an old Lunati flat tappet hydraulic with .550-inch lift and 245 @ .050 duration with a 108-degree lobe separation angle. The new Voodoo delivers .655/.663-inch lift and similar 243/249 @ .050 duration with a wider 110 LSA, which should broaden the power curve a bunch.
Before Joey D could try the cam swap, we needed baseline numbers from the Northeast's premier dragstrip (Raceway Park in Englishtown, New Jersey) and dyno digits (SLP Performance Parts in Toms River, New Jersey). E-Town is famous for its great hook, and SLP has a state-of-the-art SuperFlow chassis dyno. Here were the baseline results for e.t. and rear wheel horsepower. At the track on 15-inch Nitto drag radials, the NJ55 went 12.77 at 107.89 mph, while it spun the dyno rollers to 329 hp.
With solid baseline numbers, Joey got busy installing the cam kit (cam, lifters, springs, retainers, roller rockers, pushrods, and timing set) at his home workshop. Initially, the cam was installed with 4 degrees of retard. The retarded cam timing bled off 40 psi of cranking compression (only 135 psi), causing the motor to feel somewhat sluggish. Once the cam was degreed in to the cam card (4 degrees advanced), cranking compression went back up to 175 psi. Before the cam swap the cranking compression was 170 psi in all eight cylinders. Here we definitely illustrated how important it is to degree in the cam.
Once the new stick was properly positioned, the idle vacuum (1,100 rpm) was up 3 inches and we noticed increased throttle response and driveability. Unfortunately, the Rat would consistently start breaking up at 5,100 rpm. With that problem and four more parts to test, we hoped we'd find the solution while dyno testing at SLP. On the dyno, we could closely monitor the air/fuel mixture ratio.