I concur with Techinspector 1. Way back when, (and I'm plenty old enough to remember "way back when" - like the 50's) there were plenty of classes for small displacement engine/heavy cars. These guys successfully used some very heavy flywheels. I recall one stock bodied Willys coupe that ran a little 170 c.i. Mopar slant six and was plenty competitive in his class.

The pracctice was to build up as high rpm as one could manage while sitting on the line, in effect storing up bunches of horsepower in the spinning flywheel, then dropping the clutch. If the clutch held together, the car departed abruptly.

The downside was that once that stored-up horsepower petered out, that flywheel became just a big heavy chunk of steel for a little dinky engine to lug along.

But! If things worked together just right, the heavy-flywheel guy could put humiliating holeshot on the competition that was enough to get him to the lights first. Usually just barely, but what the heck. That's the whole idea, ain't it?