Larry McBrides Five-Second Bike
by Jeff Burk
One of the last great barriers in drag racing has finally been broken. Almost 50 years after Al Keys drove Chet Herberts "Beast" Harley into the tens at over 121 mph, Larry "Spiderman" McBride made the first five-second motorcycle pass at the "mineshaft" otherwise known as Houston Raceway Park.
McBride, who is a regular competitor on the ProStar Top Fuel circuit was making exhibition passes at NHRAs Supernationals when he ripped off the historical five-second pass on the pool table smooth surface of Houston Raceway Park. DRO thought our readers would like a little more information on the pass itself and the two-wheeler that accomplished that feat.
First, lets break down the pass itself. The bike covered the first 60 feet in 1.052 seconds, the 330 in 2.706 seconds and the eighth-mile in 3.94 seconds at 179.04 mph. It took only 5.052 seconds for the fuel bike to get to the 1000 ft mark and it tripped the quarter-mile beams in 5.993 seconds at an astounding 243.68 miles per hour.
The bike gained an incredible 64.64 mph from the eighth mile to the finish line.
"We were a little suspect of the eighth mile speed," said McBride. "The bike usually runs in the 190s in the eighth but Ive never had the bike pull on the back half of the track like it did on that pass."
If there was any doubt of the legitimacy of the 5.99 lap, that was put to rest the following weekend when Larry took the bike to a Pro Star race at Gainesville, FL where he ran laps of 6.08 and 6.10!
Now we will look at the machine itself. The bike has a 100 inch wheelbase and a frame made of Chromemoly and was welded up by Race Visions chassis. The four-cylinder cases and the crankshaft are by Puma and the inline four-cylinder engine displaces 1511 ccs (or for you car people, 93 cubic inches). The cylinder heads are Vortex by Ward Performance. McBride feels the cylinder heads have a lot to do with the increased performance his bike has shown recently.
"We changed over from a four valve head to a two valve head and we immediately started running better," explained McBride. "We used to drop holes going down track but with the two valve heads the engine never misses a beat."
A Whipple supercharger turning at just 52% overdrive pushes the 92% nitromethane-fuel mixture through the motor.
According to McBride the bike, which weighs 1073 lbs, made 1207 hp on the 5.99 lap.
Like any other nitro burning machine the secret to making it perform at its best is in the clutch. The right set-up on the clutch keeps the engine loaded going down track and, with a nitro burning motor, that is absolutely essential. McBride uses a three-disc clutch to accomplish that but he credits an NHRA Top Fuel team with helping him get a handle on the clutch. Seems like the Alan Johnson group has been helping McBride with his clutch program.
"Im running a three disc this season and I will be using more discs next year," McBride said.
The 5.99 wasnt a fluke according to McBride. "Weve got plenty left. On the 5.99 lap we didnt even fuzz a plug. We only turned the motor 10,100 rpm on that lap and we could go to 12,000 easy. I think that there is a lot left in the motor."
If he is right we might see a four-second Top Fuel bike before the party is over.
Photo by Dave Kommel
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