The Showdown
After the smoke of bench racing, theorizing, and wishful thinking cleared, we were left with the one measurement that counts: the drag test. The proverbial bottom line. Just the car versus the Chrondek. No excuses, please. First we went to the track packing the "little" 427. Come to think of it, we drove the Nova all the way to L.A. County Raceway (LACR). That we were able to drive the SuperNova over 60 miles to LACR speaks volumes. This healthy engine not only provides gobs of torque and power, but it wasn't even remotely objectionable on the somewhat long haul to the high desert of Palmdale, California, or in around-town traffic.
Our first pass after unloading the contents of the trunk, swapping radials to slicks, and giving the Nova a brief cool-down netted us an uncorrected (LACR is 2,700-feet above sea level) 11.94 at 111.57. Things looked promising. Our best pass of the day was an 11.76 at 113 mph with a 1.59 60-foot time. The added torque of the big-inch small-block obviously agreed with the 60-foot clocks. Despite the great performance, would it be enough to stave off the Rat motor? We would soon find out.
A couple weeks later we were back at LACR, armed with the 509-inch big-block nestled snugly between the fenders of project SuperNova. We towed it for this outing as we were pressed for time and didn't have the opportunity to perform any shakedown on the street. In hindsight, we fully believe that the 509 would have provided trouble-free street manners, although we will need to step up the cooling system with a bigger radiator. We reused the Turbo 350 and torque converter of the previous small-block drag test in order to keep as many constants as possible. We knew that the 427-inch small-block was a solid 11-second performer, but would the added torque, horsepower, and weight prove significant? We were about to find out.
The first pass off of the trailer netted us a less-than-spectacular 12.55 at 106.35 mph. Thinking this was a fluke, we backed that pass up with a 12.43 at 106.16 mph. Traction was good, but the SuperNova just wasn't pulling. We decided to remove the hood as it was sitting very close to the top of the carburetor, and we added an air cleaner in order to direct air into the carb (and obviously to keep damaging dirt particles out). The Nova promptly responded with an 11.92 at 111.62. Now we were getting somewhere. Fiddling with float levels and launch rpm rewarded us with a best e.t. of 11.60 at 114.25. It is important to note that the day of testing was considerably hotter than when the previous small-block testing was accomplished, and the SuperNova's cooling system proved inadequate for the big-block. Our best time resulted when the car was given a full 30 minutes to cool down.
Excuse Time
So, what did we learn? Many things that look good on paper don't necessarily work out the same way in practice. When examining dyno curves, power-to-weight ratios, and such, the big-block wins hands down. For a balanced package with good power and low weight, the small-block is the weapon of choice. In all fairness, weather plays a significant role at the dragstrip. Yet despite less-than-favorable temps and air quality, the Rat took top honors at the track.
If the heat claimed a couple of tenths, we're looking at a very-low-11-second piece at sea level. Of course, once you're in the low-11-second range, high-10s are right around the corner. Is there more left in the big-block? We think so. In fact, we'll be playing more with the Rat in an effort to further optimize the combination. We'll also be replacing the much-abused Turbo 350 for a tricked-out Turbo 400 and a converter better suited to the combination.
We also learned that Bill Mitchell offers some kick-ass crate motors that take the guess-work out of picking a combination for your street/strip bruiser. You simply need to figure out your budget and how fast you want to go, and let Bill Mitchell sort out the rest.
Weight is one of the main...
Weight is one of the main premises of the small-block versus big-block argument. The small-block weighed in at 3,325 pounds with driver, and the big-block tipped the scales at just over 3,500.
It's also time for us to add a rollbar and some basic safety equipment as the little SuperNova is growing up in a hurry. So stay tuned--this debate is far from over.
The Combo
* MT ET Drag slicks, 28x9.0-15
* Dana 60 with 4.10 Detroit Locker
* Turbo 350 with B&M Holeshot 10-inch 3,000-stall converter
* Hedman 1 ¾-inch headers on small-block
* Hedman 2-inch headers on big-block
* 3-inch exhaust with Dynomax Ultra-Flow mufflers
Note: Both engines used supplied carbs with no jetting changes. Both engines also came with HEI and pre-cut wires, but we used our MSD Ready-to-Run distributor in both cases.