The Pantera Club of Northern California gathered at Rockwell Engineering in Santa Clara for the Second Annual PCNC Dyno Day . Charlie Rockwell graciously volunteered his time and the use of his facilities to enable us to diagnose how our cars run. Larry Stock orchestrated the event, and provided the barbecue and charcoal for the obligatory burger burn.

This event had two distinct purposes. PCNC members were able to have their cars evaluated on the chassis dynamometer, to determine exactly how much horsepower was being produced. As an additional bonus, owners could see what the levels of emissions were, and from that, determine if the car was jetted properly, had an ignition problem, etc. Along with testing members' cars, the Horsepower Clinic portion of the day centered around a test mule Pantera. The intent was to start out with a bone-stock car, and gradually make modifications (i.e., carburetor and manifold swaps)' with the hope of discovering exactly what kind of gain (if any) is available from these various components.

The original scenario involved Larry Stock's car as the mule, but as you know, he grenaded his motor at Las Vegas, and his new motor would no longer be stock. Fortunately, Jim Kuehne stepped in and volunteered the use of his still-stock car. The plan of attack called for Jim's car to be tested, then pulled off the Dyno, and while a modification was being performed, another member's car could be tested, thereby maximizing Dyno time.

By the end of the day, there were a lot of lessons learned, and more than a few egos deflated as here-to-fore-unknown engine woes became apparent to all watching the goings-on. There was also a new undisputed king-of-the-hill in the normally aspirated horsepower war.

The member's cars horsepower numbers are reproduced in the table below. To provide a general description of a non-stock motor, "salsa" guidelines are used. Carburetors are all Holley, with either Manual or Vacuum secondaries. As a rough estimate, engine horsepower can be determined by multiplying rear-wheel horsepower by a factor of 1.26.

Most cars that weren't fully tested were simply running to poorly to make continued testing worthwhile, or even physically possible. Lee Scales' Pantera initially had the coil hooked up incorrectly and even after that was fixed. The car appeared to be suffering from fuel starvation, and would not pull any sort of heavy load. Hal Harter had a bad spark plug wire, Joel Gust had intermittent ignition problems, and Ken Levin fouled a plug. Roy Hanshe (whose data I didn't record) couldn't reach more than 4500 RPM, as his engine would cut out completely, and the car would backfire most impressively. The interesting thing is, Roy was the only person who was aware he had any sort of problem at all, as during normal street driving, these sorts of problems are usually masked. It all proves the value and importance of Dyno-testing your engine. Petar Harks had his own set of problems. He has a brand new motor, which incorporates port plates (which are all the rage these days). The problem is, he is using an Edelbrock Torker manifold, which (at least on the 351C model), is designed for anything but torque production. In fact, it is a high rpm, high horsepower intake, and when coupled with this restrictor plates, the result is complete havoc in the combustion chamber. He tried three different carburetors (which worked fine on the other cars), and the car ran so rich that the meter was pegged, and the sound of backfires filled the air.

Ted Lawson was one of the happier members after his car was tested. His Hall-built motor produced the second highest horsepower rating (257 hp @ 5500 rpm, but the powerband fell off a cliff shortly afterwards, dropping to 216 hp @ 6000 rpm. Charlie Rockwell determined that the primary jets were two sizes too small, and the secondaries were too rich. Also, the car had a consistant backfire at idle, which everyone was at a loss to explain.

The undisputed champ of the day was Roger Sharp. His motor even sounded meaner than the other cars when he drove in onto the Dyno. He has recently installed a big buck solid lifter powerplant, and the results speak for themselves. His car was producing as much horsepower at 4000 rpm as most others were producing at 6000 rpm. Is final result was just shy of 300 horsepower, which is a lot in any body's book. Further more, the motor was belching clouds of black smoke from the exhaust (he joked that birds were going to start falling out of the sky at any minute), as it was much too rich. Once properly dialed in, it is likely to produce even more horsepower!

Now while these numbers are pleasant to look at, and provide their owners with a reference point for further modifications and tuning, they really don't provide much objective data. For truly informative (as opposed o merely descriptive) results, a standard had to be established, against which changes would then be measured. To that end, we turned to the mule.

Unfortunately, Lucas, the Prince of darkness, reared his ugly head, and after only the fourth trial, Jim's Pantera stopped stone cold dead at 5000 rpm. The silence was truly deafening. A bit of tinkering, coupled with some appropriate lanquage, got the car started again, but it quit again shortly thereafter, and smoke started to waft up from the passenger side seatbelt retractor. So the car was pushed off the Dyno, and the ratchets started to whir, and before you knew it, half the interior was lying on the ground. It turns out that a wire leading to the automatic choke had grounded out, causing a short and subsequent electrical fire. The charred wire was removed, and a new wire spliced into the harness, but so much time had gone by that it was impossible to continue testing. As a consequence, only four configurations were tested. The results are as follows.

As can be seen, real progress was being made. The switch to a Holley 600 cfm carburetor accounted for an increase of 22 horsepower, and the Edelbrock intake gave another 10 horse4power. It is anybody's guess to exactly how far thing could have gone had we not run of time. However, we now have an idea of what is in store for us next year! Some club members took Charlie Rockwell and his wife out to dinner to express our appreciation for all his efforts, and a few members have returned to have their cars tuned. After seeing all problems that supposedly well sorted cars had, it seems that a visit to Rockwell Engineering (especially at a smog check time) for a full diagnostic and Dynotune is virtually a mandatory procedure!