Control Line: Racing
NEW K&B prototype .40 Rat and Formula "40" engine. I just recently received a new prototype of K&B's .40 rear-valve racing engine. Careful observation of this engine shows special, phenolic-cage bearings as well as the front housing being permanently affixed to the case with epoxy. In addition, the cylinder timing is the same as Billy Hughes' Nats-winning K&B .40. One significant change is the subcrankcase pressure release, which is a small hole drilled in the rear of the crankcase just below the exhaust header. This reduces the crankcase blow-by pressure and should improve performance. Weather this winter in the Midwest area has been extremely cold, and I have not been able to compare this engine with my standard K&B 6.5 engines. I will make tests in performance comparisons and inflight comparisons as soon as the weather cooperates.
Control Line: Racing
COOL FUEL. I have just finished flying in my third major contest which used the "10%-nitro rule" in all Racing events. The most recent contest, held in Chicago on the Wabonzee Junior College parking lot, featured fuel from three different manufacturers of 10% nitro. The metal cans of K&B 10% nitro fuel were not quite as evident on the field as were the transparent jugs filled with either a bright-green colored 10% fuel or a local brand called Go-Pop, which was bright red. I tried one tankful of each of these unknown blends in my engine and found that the performance was (unexpectedly!) quite similar. For simplicity's sake, during the day the fuel was rationed out per event, with the same brand always being used in that particular event. (In other words, K&B for Scale Racing, the green for Slow Rat, and the red for Fast Rat.) The Sport Race was run on a combination of the remaining fuels blended together in a transparent jug.
Control Line: Racing
FUEL PROBLEMS. The "10%-nitro" fuel rule has been running into problems of product inconsistency. We have been flying now approximately 10 months in our Midwest area utilizing our "10% fuel" rule in all Racing events. It has slowed the events down approximately one second in seven laps for Rat and Scale Racing, but utilizing "contest-supplied fuel" has caused numerous problems. During one particular recent contest, we found out (later, after analyzing) that a manufacturer's "economy blend" used nitroethane instead of nitromethane. In addition, we found approximately 6% water in the fuel, and the oil was of undetermined origin. Serious competitors spend a considerable amount of time massaging their engines for maximum output; and, obviously, their propeller-testing, restart, and speed are measured on a 10%-nitromethane fuel blend.
I985 NATS: CL Racing
RACING at the 1985 Westover Nats is history. With the 10%-nitro-fuel rule in all CL Racing (except Mouse), performance was, surprisingly, down only slightly. The rule brought heat times very close, and the finals in each event were won or lost on time spent in the pits. The circles were laid out in the same basic area as at the 1983 Nats, but a much better job was done in "hole-filling" and tar-strip removal. The Quality Inn in Chicopee was again the focal point for AMA HQ, but due to space restraints, the hobby shop and some processing was done in a building on the base that served as AMA HQ from about midweek until the end. This building was located at the entrance to the Nats flying site, and colored signs were used to direct spectators to specific events. A carnival atmosphere dominated the area around the entrance, with numerous vendors selling food, drink, and souvenirs.
Control Line: Racing
FINGER PROTECTION. As I travel around the country, I see a variety of methods for protecting the pitman's fingers. The majority of these usually involve a heavy leather glove, and in some cases the leather glove has a rubber end on the flipping finger to reduce any trauma to the finger used for starting. Obviously, with the advent of fiberglass and carbon fiber propellers which are filed to a variety of pitches, the blade can certainly get extremely hard and sharp. One problem which seems to manifest itself is the inability of the pit man to use his hand for other tasks (needle valve adjustment) when it is shrouded completely with a heavy leather glove. Some attempts have been made to minimize this problem, and they usually involve cutting the fingers from the glove, leaving one or two digits available to do other jobs.
