The BME Bulletin #2
Bill Miller Engineering's Top Fuel
Blog
A LONG TIME COMING It's been a while since the last Bill Miller Engineering Top Fuel Team's electronic newsletter was dispatched through cyberspace, but that's not because the team has been taking it easy. In fact, the BME Team has been working overtime to solve the mysteries of Top Fuel engine management. When last we heard from the intrepid BME crew, team owner/crew chief Bill Miller was in the midst of developing the Mark II version of the Gibson-Miller Supercharger for the nitro-burning classes. With mandated restrictions on blower designs and a maximum of 85 percent nitromethane in the fuel tank, one of the last avenues to improved performance is a more effective supercharger. But—if you build a better blower, racers won't beat a path your door until they see time slips. Thus, of late, the main role for the BME Okuma/Red Line Oil Dragster is serving as a test bed for new technology in drag racing's blown-fuel classes "Our tests have shown that the Mark II Gibson-Miller Supercharger moves more air, and consequently, it requires more power to turn it," Miller explained. "Last season we used a 14mm-pitch, helical blower belt with good success, however, with the improvements we've made in the supercharger; that belt had reached its limit. We switched to a stronger 11mm, straight-cut belt at the Atlanta race and the engine stopped throwing off blower belts. But eliminating the belt slippage meant the tune-up was now off because the engine was getting more air. Consequently we missed qualifying by 21 thousandths of a second in Atlanta, but knew we'd solved the problem." It rained on the BME team's parade in the next two races, in Madison, Ill., and Topeka, Kan. With bad weather limiting qualifying to two sessions in Madison and three in Topeka, the BME Dragster missed the cut for both fields, with another close-but-no-cigar, 17th qualifying spot in Kansas. "It's tough for a part-time team like ours because we're usually one of the first cars on the track after it's been sprayed and scraped," Miller noted. "It's difficult to gauge a fresh track, but that's just the way it is when you don't run the full schedule. We didn't qualify in Topeka, but we did make progress by increasing the fuel volume. If you have 5 percent more air going into the engine with a Mark II Supercharger, it stands to reason that you need 5 percent more fuel." The next stop was Route 66 Raceway near Chicago, and the BME Dragster was back in the game. Increasing the fuel volume to 85 gallons per minute at the top end and raising the compression ratio produced the season's best qualifying performance: 4.550 seconds at 319.671 mph which put Bradshaw 12th in the field. Driver Alan Bradshaw faced Doug Herbert in the first round of eliminations. Bradshaw got a huge holeshot (.064 to .137 reaction times) and was leading at half-track when the tires spun and the engine backfired. "After losing that race, I knew I had to put more fuel in through the supercharger and richen the mixture to keep the fire out of the blower manifold," Miller commented. "Top Fuel engines typically have 12 or 13 percent of their total fuel volume delivered above the supercharger, but I went to 17 percent for the next race in Norwalk, Ohio. "That fixed the backfiring problem, but the Norwalk track was slippery in the sunlight. The engine dropped cylinders on two qualifying runs, and we had another DNQ. That was very disappointing because we had a large group from Okuma at the track." Persistent rain at the team's next race in Seattle limited qualifying to a one-shot session. Bradshaw made the field with an out-of-the-box 5.020/284.69 mph run that was good for the 12th spot on the qualifying sheet. "On Sunday we raced Tony Schumacher in the first round of eliminations, and it was an excellent race," Miller recalled. "Bradshaw did his job with another holeshot and put .026 in the bank at the starting line. He ran 4.62 at 320 mph against the Army car, and Schumacher beat us by 12 feet. At least we kept them honest." The BME team wrapped up the summer swing in Sonoma, Calif. In the Friday night qualifying session, the sudden influx of cool air from the San Francisco Bay meant that the tune-up was dangerously close to the edge. The bomb went off at 1,000 feet, filling the night with flames and ending the session early. When qualifying concluded on Saturday, the BME machine was again in the unlucky 17th spot. Despite the setbacks, Miller remains optimistic about the season. "So far in 2007, we fought a blower belt problem and finally fixed it," he noted. "Then we fought the fuel volume problem, and eventually figured that out. Alan Bradshaw is doing a great job as a driver and an ambassador for the team with our sponsors and fans. "At the end of the day, the BME Dragster is still an R&D vehicle for Bill Miller Engineering," he observed. "We're in the business of making connecting rods, pistons, pins and superchargers. What better place to test these parts than on your own vehicle?" Next up for the BME Top Fuel team is the Mac Tools U.S. Nationals in Indianapolis on Labor Day weekend. Surely there are better days and better results ahead for the black and yellow machine.
BME RACE RESULTS
NEXT RACE
Mac Tools U.S.
Nationals
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