Nowadays, tuning your engine can be as simple as downloading a file and putting it into your ECU, even though this low-cost solution has its safety and performance limitations. But what if you find yourself at the other end of the complexity scale, say, with a 2,000 HP Big-Block Chevy on a ’71 Nova strapped to a hub dyno? This already sounds like a desirable scenario and yet we’re here to add a twist: there are no sensors to feed you data.
The 656ci (10.75L) V8 animating this Nova has no desire to talk to a laptop. You see, there’s no electronic fuel injection here, with the mechanical monster relying on a blow-through carburetor—instead of the boost (we’ll get to this in a moment) reaching the cylinders directly, it’s being, well, blown through the carb.
Responsible for the forced induction is a Procharger F3-136 centrifugal blower. With the help of C16 racing fuel (117 octane rating as opposed to the usual 91/93 of premium pump gas), this pushes the motor north of the 2,000 horsepower border, as demonstrated at the 3:18 point of the first YouTube clip below—the soundtrack is on the house.
The answer to the obvious how-do-you-work-on-such-a-setup question comes from Steve Morris Engines, the Detroit-based boosted engine developer whose name rings quite a few bells among drag racing enthusiasts—this is also the company supplying the quad-turbo V16 muscle for the United Arab Emirates’s 5,000 HP Devel Sixteen hypercar, although this machine yet to emerge from the prototype stage (this is another story for another time).
The man doing the explaining is founder Steve Morris himself, who’s been in the business for decades. And his old-school approach is about reading the spark plugs.
“It’s a good thing to have oxygen sensors, it’s a good thing to have as much information as you can, but they’re just numbers and they’re just reference numbers that are helping you tune. But, the be-all and end-all is always the spark plug,“
In fact, Steve states that the procedure of taking apart the spark plug and checking its porcelain, as well as its strap is the basis of all engine tuning work: “If your tuner doesn’t look at the spark plug, he’s not a tuner, he’s just a computer guy,“
Now, whether you have a drag animal in street car’s clothing, as is the case with this Chevrolet Nova, or some other sort of build, you might wish to know more about the art of spark plug reading.
And the second video below brings just that, as it sees Steve delivering a condensed explanation of the analog procedure we’re discussing here. So next time when you look at your spark plugs, remember they can do much more than keep your engine revving.