Q A friend of mine has after-hours access to a brand-new Dynojet dynamometer. I've always wondered how much horsepower and torque my 1974 Ducati 750 Sport actually makes. It's totally freshened up and as close to mechanically perfect as I can make it, but I don't want to hurt anything. Is a dyno run or three any harder on the internals than an enthusiastic blast through the canyons? Is there anything I should know/do/make allowances for in advance? And what can I do with the resulting data printout aside from posting it on my office wall?
A According to Keith Royle, Dynojet's Director of Dyno Sales, as long as your engine is in good shape and warmed up, a few dyno runs shouldn't hurt it. Start with a few easy pulls under acceleration and deceleration, rolling the throttle on more aggressively as you go once everything is up to operating temperature. The subsequently higher cylinder pressures help rings and cylinder walls get better acquainted.
"A dyno run is no harder on your engine than vigorously running up onto a freeway entrance ramp," Royle says. "And monitoring vital data such as the air/fuel ratio, engine temperature and coolant temperature in the dyno room can avoid costly mistakes such as a leaky intake boot leaning out the mixture or a loose oil line.
"When the first Suzuki Hayabusas came out, we were mapping our Power Commander and working on development. The more dyno runs we made, the more power that bike put out on the dyno. After about a half-dozen runs, we picked up almost 6 bhp, so that alone would support the dyno break-in theory. So yes, you can make a series of dyno runs with a fresh motor, and might even gain a bit of power and longevity by doing so. Also, you'd have a good baseline dyno run to use as a tuning guide for further upgrades and tuning."