Looks Like A Street Bike Runs Like A Racebike
LOOKS LIKE A STREET BIKE RUNS LIKE A RACEBIKE
Byron Hines' Idea of a Street Machine has Nothing to do With Cruising.
John Ulrich
"If he had this motor in his bike, we'd all be in trouble," said Byron Hines, glancing from his street bike to a competitor's dragbike.
Hines built the GS1100 Terry Vance used to win the IDBA and NMRA Pro Stock Championships in 1980. The man who had just driven into the dragstrip parking lot regularly ran against Vance in the Pro Stock class.
Exactly what Hines meant wasn’t clear when he said it, but it would soon become obvious.
Hines has his own idea of what a street bike should do. The GS1100 tested in this issue was fast in stock form, turning 11.10 sec. and 120.32 mph at the drags. Hines’ GS1100 Suzuki looks stock, except for the VHR (Vance & Hines Racing) exhaust system and a deep notch cut into the front of the seat. It weighs 527 lb. with gas and comes complete with turn signals and side stand.
But in fact it isn’t a street bike in anything but appearance.
On a balmy December morning in Los Angeles, Byron’s Suzuki ran the quarter mile in 10.23 sec. with a terminal speed of 139.53 mph. With stock shocks. And a 4.50-17 IRC street tire. With me aboard.
Six of the eight passes were deep in the 10-sec. bracket, every one at 137 mph or above.
Leaving eight burned-rubber scars streaking down the track from the staging lights to past mid-track. More than an eighth mile of rubber was laid onto the pavement with each run. That totals about four miles of rubber applied to the asphalt in eight passes.
Riding the bike in the street-appearance mode was an exercise in sky-shot wheelies with the rear wheel churning. The engine made so much power that it yanked the swing arm to one side as the clutch was engaged, pulling the rear wheel out of line and and making the bike jerk to the right through the first three gears. That meant wrestling the bars all the way through third gear just to stay in the same dragstrip lane!
Just for the sake of experience, I made four more passes after Hines had installed a wide rear wheel with racing slick and a set of wheelie bars with struts replacing the shocks.
The churning, burning, wandering rear end wasn’t a problem anymore. After long burnouts to heat the tire rubber, the rear slick hooked up immediately off the line and stayed hooked up, the bike slithering down the track on the rear wheel and wheelie bars as the handlebars wandered at will.
My first wheelie-bar pass was 9.81 sec. at 142.85 mph. The best pass—the third—stopped the clocks at 9.50 sec. and 142.63 mph. The other two passes were 9.60 and 9.61.
After each set of two runs, Hines used a large, generator-powered floor fan to cool down the engine.
This isn’t a streetbike. It’s a racebike that looks like a street bike. If it weighed about 35 lb. less, the thing could qualify at a Pro Stock national, street chassis, air box and all.
It’s big, 1260cc with 78mm, 13.8:1 c.r. forged Wiseco/VHR pistons. Gas ports lead from the piston deck to inside the top ring land, allowing combustion pressure to push the ring against the cylinder wall for better sealing and less blowby. The top ring is thin, 0.035 in. The second compression ring is 1.2mm thick. A conventional three-piece oil-control ring is used.
Oversize liners must be installed in the cylinder casting to accommodate the big bore, and a copper o-ring is fitted in a groove milled around the top of each cylinder. The copper o-ring prevents head gasket blow-out from the high compression.
Most engine tuners selling to the public polish head ports to a mirror finish, Hines doesn’t, instead going dramatically the other way by scratching the intake ports with a porting tool after the final 60-grit finish is applied. According to Hines, the rough finish doesn’t affect air flow on his flow bench, but does ensure better fuel atomization. The port roughening extends the length of the port except in the valve seat area, where the port is kept smooth.
Measured from 0.050 in. lift, the intake cam opens the valves 13° BTDC and closes them 53 ° ABDC, while the exhaust cam opens the valves 53° BBDC and closes them 13° ATDC. Lift is 0.350 in. for both intake and exhaust, and duration in both cases is 318 °.
The intake valve heads are 28.5mm, larger than the stock 27mm intake valves, but the exhaust valves are stock, 23mm.
The crankshaft is welded at the press fits to keep it from twisting under power, and the cam chain tensioner is converted from automatic to a manual-adjust, locking system. The clutch hub has stiffer damping springs and heavy-duty rivets installed for strength, but the clutch plates are stock. Heavy-duty clutch pressure springs are used.
The ignition system is a Martek 880 with Blue Goose coils and Martek 440 pick ups.
Hines says that the star of the show is the bank of 33mm Mikuni Smoothbore carburetors, being tested by VHR but not yet available for sale. The new, oval-throat Smoothbores flow better than ported Amals, better than CRs, better than any carbs Hines has tested on his flowbench.
Hines is entitled to his opinion, but in reality the carburetors are not the star of the show. Sure, they give good flow, but anybody—providing they can get the carburetors in question—can bolt on carburetors.
No, the real star of the show is the shifting system Hines has carefully constructed and concealed underneath the countershaft cover.
To the uninformed observer watching Hines make a pass on the bike, it appears that Hines is the slickest, quickest-shifting pilot this side of an air shifter. Hines does nothing to dispel that idea, and watching him ride gives no clue to what is happening.
The bike rolls up to the line. The rider engages first gear, looks at the tree . . . there! That’s it, a tiny flick of the right thumb, almost undetectable, moving the engine kill switch from “on” to “off.”
The engine does not die, but that movement activates the shifting system. When the system is working, the ignition is cut off whenever the transmission is not fully in gear. The rider lets the clutch out off the line, locks his arm at full throttle as soon as wheelstand-control will let him, and leaves it there, shifting (without the clutch) by moving the shift lever upward. The gears change quicker than can be imagined, the bike burping with each lightning-fast shift, second-third-fourth sounding like BaaaaaaaBaaaaaaaaBaaaaaaaa.
What Hines has done is take a starshaped detent plate from a GS1000 and bolt it to the outside of the GS1100 shift drum. The auxiliary detent plate, once in place, is located outside the transmission case, under the countershaft cover. A Honda starter ring gear seal (which is thin enough to fit in the available space) keeps the oil in the cases. A Kawasaki 1000 detent stop lever is located on the outside of the cases as well, its end normally fitting into one of the valleys in the detent plate star shape. When the shift drum rotates, the auxiliary detent plate moves the stop lever out of the star valley onto a star peak. In other words, the bumps on the star push the lever down when the shift drum is rotated. The lever moves down and hits the micro switch, which kills the engine. Killing the ignition for a microsecond unloads the transmission gear dogs and the transmission slides into the next gear as the rider pulls the shift lever up.
It all happens so quickly that no human could shift as fast using the clutch. In Hines’ tests, the device cut 0.20 sec. in elapsed time, as well as reducing chain stretch and clutch wear.
The hard part is keeping your elbow locked rigid and resisting the instinct to back off the throttle—even a tiny bit— with each shift, especially the shift from first to second.
Once that technique is mastered, cutting low-10-sec. passes is easy.
Which brings us to the next, and last, point.
If some guy driving a Toyota pickup carrying a generator, a fan and a stocklooking GS1100 with VHR stickers on it pulls up at the local hangout and offers to run his street bike against your street bike for cash, don’t do it.
It might be Hines.
