Camshaft Mysteries Revealed - How They are Made and What Their Specs Mean

Have you ever wondered about the specifications stated on the outside of a camshaft box, what they mean, or how to take advantage of them? Valve lift is often the topic that opens cam discussions. Fortunately, it’s meaning is fairly straightforward. Camshaft makers use valve lift to induce as much airflow through the engine as possible. Efficient cylinder heads on a 632 big-block Chevrolet, for example, will provide impressive flow characteristics up to 1.000-inch of valve lift—while most Mountain Motor Pro Stock teams seek valve lift well in excess of this—and increase it further by employing 2:1 rockers.

“But most Sportsman guys with a 632,” explains Jeff Sams of Lunati, “are reluctant to select a camshaft with such large valve lift because it is so destructive to parts.” Sams, a Pro Stock Mountain Motor owner, builder and tuner, bridles, “So, Lunati devised a happy medium using an .810-inch lift.” The .810 camshaft can operate with the normal 1.70/1.70:1 rocker ratio or with increased rocker ratios of 1:85/1.75:1 or even on 1:85/1:85:1. Sams continues, “Normally, it’s desirable to favor the inlet valve with more lift because it responds better. The exhaust valve, in contrast, doesn’t benefit as much from lift—it responds more to duration.”

Still, valve lift needs to be considered carefully. Let us assume we are tuning a drag race 632-ci big-block Chevrolet engine and our race camshaft provides a maximum inlet valve lift of .810-inch and maximum exhaust valve lift of .778-inch. This means the incoming charge has a maximum opening around the inlet valves of .810-inch and the exhausted gases flow through a maximum valve opening of .778-inch as they escape into the pipe.

Accounting for valve lash and a little pushrod deflection, valve lift is usually reduced by around .030-inch. Perhaps the first question should be whether or not the amount of valve lift specified on the cam box is sufficient to support the torque and rpm of my engine? In addition, the camshaft lobes, via the pushrods and rockers, open the valves, but it is the springs that close them.

Big-block and Pro Stock Mountain Motor exponent Chuck Lawrence of Jon Kaase Racing Engines suggests, “Knowing the amount of valve lift conveys many important spring requirements. The valve lift figure, for example, determines how tall the spring needs to be to enable it to open fully without becoming coil bound.

“It is also important to ensure the bottom of the spring retainer does not make contact with the valve stem seal or the valve guide. The key to selecting optimum spring pressures is to find the lightest pressure that will close the valve, keep it closed, and not allow it to chatter on the valve seat. Some of Kaase’s racing big-blocks might function with springs providing 500 psi of seat pressure (the pressure exerted on the spring when the valve is closed) and 1,200 psi of open pressure. Over time valve springs lose their strength so to avoid seat chatter we might change them when their seat pressure deteriorates to around 300 psi.”

Lobe Lift
The next term expressed on the camshaft box is lobe lift. Lobe lift and rocker ratio are a function of valve lift. Consider a lobe lift dimension of .476-inch and multiply it by 1.7 (the common rocker ratio of a big-block Chevrolet) and the resulting valve lift will compute to around .810-inch.

Increasingly, camshaft cores and journals have become larger in diameter to contribute greater stiffness to the valve train and also to accommodate larger lobes. Large lobes cannot be fitted in the engine block’s camshaft tunnel unless the journal diameters are even larger. In today’s racing engines, bearing journal diameters of 65mm are not uncommon, while professional teams are using nine-bearing 70mm camshafts in engine blocks that permit their burly proportions. Sufficient working clearance is usually their chief impediment. At these levels of competition, where the production of maximum power is the only objective, engine builders will try to find an engine block that will accept the largest cam bearing diameter, and therefore, the largest cam lobe. In addition, they will increase their rocker ratio to around 2:1.

But the greater the lobe lifts, the greater distance the lifter travels within its bore, and as a result, the greater it is affected by wear and tear. In an attempt to reduce lifter wear some race engine builders select a camshaft with moderate lobe lift and increase the rocker ratio to gain extra valve lift. Either way the spring is exposed to hard labor and needs replacing when its strength begins to fade.

Lobe lift is calculated by measuring the lobe’s overall dimension (toe-to-heel) and subtracting its base circle dimension. For example, the toe-to-heel dimension of the big-block cam specs displayed on the box is 1.462 inches and its base circle .986-inch. Its lobe lift, therefore, will be calculated as .476-inch.

Adv. Dur.
The term “Adv. Dur.” denotes advertised duration. Though not so commonly used as other references, it indicates seat-to-seat duration. Lunati measures its advertised duration of hydraulic camshafts at .006-inch. (valve off its seat), and often refers to it as duration at .006-inch. The advertised duration of solid camshafts is measured at .020-inch. in order to compensate for valve lash. 
Dur. @ .050-Inch
In contrast, the term “Dur. @ .050-inch” tappet lift is very common. Reducing the duration reduces the overlap, which in turn increases cylinder pressure.

Aided by a degree wheel and with a dial gauge indicator on the lifter, Jeff Sams explains how it is measured: “First you rotate the engine clockwise until your lifter is raised .050-inch. To eliminate the slack in the chain, turn the wheel counterclockwise by .100-inch and then clockwise .050-inch. Mark the number on your degree wheel and continue to rotate it clockwise, through its cycle, until the lifter falls back to .050in.”

Valve Lash
Valve lash is the mechanical clearance in valve trains with solid lifters. It is measured between the valve stem tip and the underside of the rocker arm. Valve lash is intended to provide the greatest amount of valve opening as the lifter travels over the high point—the nose—of the camshaft lobe, while still ensuring that the valve is tightly closed as the lifter travels over the low segment of the camshaft lobe, the base circle. Though some racers will attempt to gain a slight power advantage running looser lash settings, camshafts with aggressive lobes and excessive lash clearance risk damage to the valve stem tips, pushrod ends and lifters. It is also prudent to inspect the geometrical arc of the rocker arm as it sweeps across the valve tip.    

Center Line
The term “center line” refers to the point of peak lift of a camshaft lobe in relation to top dead center of the piston as measured in crank degrees. This can be changed by “degreeing” the cam. In this case, when the cam is degreed by advancing it 4 degrees, its center line will be 110 degrees. This means that the maximum lift of the Number One intake valve will occur when the Number One piston is positioned 110 crank degrees after top dead center.
To check the center line of the Number One intake lobe using a degree wheel, locate true top dead center of the Number One piston and set your pointer to zero on the degree wheel. Then place a solid lifter on the Number One intake lobe and position a dial gauge indicator on the lifter. Turn the engine clockwise until the lifter reaches peak lift and set the dial gauge to zero. Then turn the engine counter clockwise until the indicator falls .100-inch. Next, turn the engine clockwise until the dial gauge reads .050-inch and note the degree wheel reading. Continue to turn the engine clockwise (over peak) until the indicator reaches .050-inch after maximum lift and again note the degree wheel reading. Add these numbers together and divide them by 2. The resulting number represents the intake centerline.

Timing at .050-Inch Tappet Lift
The final rows of data on the box display valve timing data at .050-inch tappet lift. They are as follows: The inlet valve opens at 35 degrees before top dead center and closes 75 degrees after bottom dead center; the exhaust valve opens 90 degrees before bottom dead center and closes 34 degrees after top dead center.  

Spintron
The best tool ever devised for testing valve train components is the Spintron. It identifies and records crucial valve train characteristics such as valve bounce, tappet lofting, spring harmonics, pushrod deflection and more. Employed by all top teams where engine power is at a premium, the Spintron will check valve train performance from 500 to 20,000 rpm. It works in tandem with the dynamometer, and having one, or at least access to one, provides the race engine builder with a significant advantage. 

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The etchings on Lunati camshafts typically denote the type of cam (Voodoo); the part number (60512), which determines the grind profile; the day on which it was made (258th day of 2010); and the lobe separation angle (113 degrees).

Checking the straightness of the five journals of a 5160 induction-hardened camshaft. The center journal is the one first checked for straightness. It is permitted a tolerance no greater than .001-inch. If it meets tolerance requirements, usually the remaining journals will also pass the straightness checks. The blackness between the lobes usually indicates the induction-hardening process. In contrast, copper coating indicates carburizing, an Austempering process that also contributes a case hardening depth of around.130-inch.

A quick zap with the air hammer is used for straightening. The fuel pump lobe at the front and the distributor drive at the rear denote this cam will be used in a Chevrolet.

Lunati uses a Landis grinding machine to produce all of its premium and high-volume camshafts. The carriage securing the camshaft moves right to left and the grinding wheel moves fore and aft. Here the first three lobes are ground and the machine is stopped to check the lobes for toe-to-heal accuracy.

Simply program the part number into the Landis and 16 to 18 minutes later a perfect camshaft is born. After grinding the camshaft it is returned for further straightness checks.

Manual grinders are used to produce one-off and low-volume camshafts. This process is performed in two stages: roughing (as depicted here) and finishing.

Grinding speeds—the first essential of a quality camshaft maker. A key element in the finish-grinding process of a high-quality competition camshaft concerns grinding speed. If the speed is kept low, the quality of the grind will be high. If production numbers are allowed to trump quality and the grinding speeds are increased, the quality will be lower.

Measuring the toe-to-heal dimension to ensure the lobe has been ground to the correct size. The first check, interestingly, is to ensure the lobe is smaller than the journal, thereby ensuring the cam will fit the block!

With cam profiles already programmed in the inspection machine, it runs the ball along the lobes, comparing its findings with the design data. Its duties include measurements of taper, base circle, base circle run-out, toe-to-heal and lobe separation angles. In contrast, the essential attribute of the flat tappet cam lobe is, indeed, the taper on which the lifter rotates.

Polishing the journals is one of the final operations.

Don’t forget to read the spec card. It contains valuable details about the camshaft’s specifications as well as information about break-in lube, valve springs and how to find the center of the intake lobe.

Text and Photos by Sam Logan

Source: Drag Racer

LSX 454-R Crate Engine from GM Performance Parts

The Big Three have jumped into the grassroots performance scene in a lot of different ways, while others are dabbling in class-specific racing, the gang at GM Performance Parts (GMPP) tapped their area of expertise of crate engine production for their grassroots efforts. The GMPP catalog has staked its claim as being the leader in crate engine offerings from entry-level small-blocks and four-cylinder power plants to robust 572-ci street monsters. The company even offers a spec-engine for various circle track racing sanctions. Amongst the small and large crate engines sits its highly acclaimed LS lineup that includes green offerings (E-Rod emission-compliant packages), production-style engines, short-blocks and a stout 454-ci LSX pump gas engine. But the LS story doesn’t end with its monster LSX 454; GMPP is releasing its most powerful crate engine to date, and it’s targeting the grassroots drag racing segment. Please give a warm welcome to the GMPP LSX 454-R crate engine and all of its 720 hp.

GMPP rolled out its LSX program in 2007, and the major marketing force was on the drag strip where the company got involved with the NMCA LSX Shootout and backed several other drag racing efforts. The LSX block was an instant hit and is now a cornerstone in the world of big horsepower on the street and strip. Its popularity is no surprise since the factory speed shop worked with NHRA Pro Stock legend Warren Johnson to design a block capable of supporting 2,000-plus-hp while remaining applicable to street-only engine builds. The new LSX 454-R crate engine is merely building on the high-performance platform that was rolled out almost four years ago.

The LSX 454-R engine is not just a poked and stroked bullet that was bolted together and rushed to market. There were several LSX racers who contributed data and feedback on various combinations as well as a full-bore engineering effort inside of GM to produce the 720 hp. The highlights of the engine include the brand-new LSX DR head and intake components, but it all starts with the LSX block foundation. The six-bolt main, cast-iron block has its bores enlarged to 4.185 inches each in diameter, while the stroke checks in to the party at 4.125 inches. The forged pistons are connected to the stroker crankshaft via 6-inch-long 4340 I-beam connecting rods.

Moving topside, the main ingredients include the brand-new LSX DR cylinder heads and intake manifold. The LSX-DR heads come standard on this engine and feature CNC-porting, 11-degree valve angle and six-bolts per cylinder that are designed to be used with the LSX block. The heads are capable of serious flow numbers, and the CNC-ported intake runners push 435 cfm at .800-inch lift, while using a 2.25-inch stainless steel valve, 4.185-inch bore and 28 inches of water on the test stand. Moving to the exhaust ports shows GMPP’s handiwork on the CNC mill nets a port flow of 252-cfm at .800-inch lift, 1.625-inch stainless steel valves and the same flow-bench criteria as the intake test. For those interested in the intake port volume, GMPP lists it as 316cc and the combustion chamber is 50cc.

The in-block camshaft bumps the valves a maximum of 0.738-inch, both intake and exhaust. The rest of the cam specs include 250 degrees of duration on the intake side and 270 degrees for the exhaust (measured at 0.050-inch lift), with a lobe separation angle of 108 degrees. Mechanical roller tie-bar lifters are installed to transfer the lift to the pushrods and ultimately to a set of shaft-mounted 1.9:1 ratio roller rocker arms. Topping the induction system is the LSX-DR intake manifold designed to work on top of the heads bearing the same moniker. It accepts a 4500-style carburetor and has extra material for professional porting. GMPP tops the engine with a Holley 4500 carburetor, otherwise known as a Dominator, and it flows 1,150 cfm.

All told, the 454ci powerhouse cranks out 720 hp at 6,800 rpm, while torque peaks at 630 lb-ft. GMPP suggests 110-octane as the minimum and max rpm is 7,100. Based on quarter-mile calculations, that type of power should push a 3,200-pound vehicle into the low 10s/high nines with speeds over 135 mph. The engine is available at any one of the 4,500 GM dealers (140 are authorized GMPP sales centers), and it’s only a few clicks away online at the division’s website.

Source
GM Performance Parts
Gmperformanceparts.com

DR-1103-CRATE-LEAD

GMPP teamed up with several grassroots racers when developing the LSX line of parts. One of them was Robin Lawrence and his ‘70 Chevy Nova that competes in NMCA Nostalgia Pro Street. It’s through testing and racing efforts like this one that the LSX 454-R engine was designed and produced.

The foundation for power and reliability is the LSX engine block, which was unleashed nearly four years ago. It features cast-iron construction, six-bolt mains, Siamese bores, thick webbing, up to six head bolts per cylinder and comes in two deck heights: 9.26 inches and 9.70 inches. GMPP used the 9.26-inch version for the LSX 454-R engine.

GMPP turned to a 4340 steel crank with a 4.125-inch stroke, 2.56-inch main journals, 2.10-inch rod journal and 8-bolt flywheel/flexplate attachment. It can be purchased separately from GMPP under P/N 19244018.

The eight connected rods are forged 4340 steel I-beam pieces with a 6.000-inch center-to-center length, 2.10-inch big end and 0.866-inch wrist pin. It is listed in the GMPP catalog as P/N 19166964.

The 13.1:1 compression ratio comes courtesy of a forged aluminum piston, and it’s a flat-top version of the one pictured.

The long-awaited arrival of the LSX-DR cylinder heads (P/N 19166979 for CNC version) is upon us. The highly anticipated cylinder heads feature a rectangular port configuration that is significantly larger than the LS7 port size, six bolts per cylinder, raised intake and exhaust ports, 11-degree valve angle, big flow numbers and require shaft-mounted rocker arms. The heads are designed for engines with a bore size minimum of 4.125 inches. The heads require the use of the GMPP LSX-DR intake manifold or one that is custom-fabricated.

The LSX-DR intake manifold was designed specifically to be used with the LSX-DR cylinder heads. GMPP offers it for both the short-deck (P/N 19257851) and tall-deck (P/N 19257852) engine blocks. It was designed to flow serious airflow to complement the LSX-DR heads, but there is extra material for even further modification. Two injector bosses are cast into each runner for fuel injectors and/or nitrous oxide nozzles. It’s a single-plane-style intake manifold and fits a 4500-style carburetor.

Source: Drag Racer

Working Man - A Strong Work Ethic Pays Dividends for This Racer

Cameron Monefeldt is a hardcore drag racer and a stalwart Mopar guy; any more so and he’d have an image of Dick Landy tattooed on his chest and Walter P. Chrysler on his back.

All you Mopar guys know this is a recipe for heartache. Parts are more expensive and harder to come by, the tech and build-up information is sparse, and at the track you’re awash in a tidal wave of GM and Ford products.

Even though this story is about Cam’s ’69 Dart, it actually starts with his ’69 Plymouth Road Runner. He obtained the Road Runner from the southeast, and had it hauled back to California. Upon arrival he discovered it was severely rusted, but complete. Countless nights and weekends were spent in his two-car garage loving on his Plymouth.  The final product was a beautiful, numbers-matching, 383-powered restoration.

But like I said, Cam’s a drag racer, so it wasn’t long before he began flogging the Runner at the track. Soon one of his buddies grabbed him by the lapels and shook some sense into him, pointing out that it was much too nice to be abused in such a manner. 

Cam reluctantly parked his Plymouth and began a search for a proper drag vehicle. Now here’s the twisted part of the story. He just happens to be the lead service advisor for Selman Chevrolet, one of Southern California’s largest Chevy dealerships! He could have easily snagged one of the billion dirt cheap GM G-Bodies begging to be sold, grabbed a GM Performance catalog, checked all the right boxes, and voila, he’d have himself his racer. He might even have been able to use an employee discount to buy the parts!

But nooo, Cam just had to have a Mopar. Amazingly, in July of 2007 he came upon an unmolested, amazingly rust and dent-free, slant six-powered ’69 Dart. He hauled it to back to his two-car garage, where he gutted the interior and stripped it to the shell. Cam parted out all of the good stuff, but when it came to the engine, well, the slant six is useless, except perhaps as a boat anchor. Cam
and his buddy Chris Crisalli decided to send the six-shooter out with a bang. 

They drained all of the fluids and cruised the neighborhood for a couple of hours…still running. Next came a series of brutal burnouts…still running. Finally, the two-man wrecking crew got bored and headed back to Cam’s garage.
In a toast to the remarkably durable engine, a beer went into the carb, with that, it finally fired its last shot. 
Instead of scouring the Internet and local speed emporiums searching for the latest (and expensive) trick parts of the week, Cam, being the crafty backyard builder he is, went another route. When examining the accompanying tech sheet you’ll see “stock” used extensively. Well, the parts are stock in the sense of being stock Chrysler items, but not original to his Dart. He hooked up with local Mopar guru Jason Mayo of Mayo Performance in Pomona, California, to pick his brain and pick through his extensive inventory of used equipment. 

Some examples of his low-buck strategy: The rear leaf springs are Super Stock units from a larger B-Body instead of an A-Body. They give the Dart a better stance and position the tires better in the wheelwells. The rearend is a heavy-duty 8 ¾-inch Mopar unit. A Mopar adjustable pinion snubber provides plenty of traction and no tire spin.  The front suspension is later model Dart, which provides better header clearance. The shocks are stock. The transmission is a Chrysler 727 Torqueflight. You get the picture. Cam’s Dart hooks hard and goes straight without the expense of high-dollar aftermarket equipment.

The interior is very austere but very cleanly finished. It features an eight-point cage expertly welded up by Dave Watson of Circle City Hot Rod (Orange, California), vintage lightweight seats from a Dodge A100 van and Auto Meter gauges.

After a 16-month build, Cam was ready to race, but a small item was missing—an engine. Sitting next to his new racer was the Road Runner. A cherry picker and several hours later, and the void in the Dodge’s engine compartment was filled with the transplanted 383. This combination proved plenty potent, recording a best E.T. of 11.74.  With a taste of nitrous, he was running in the high 10s at more than 120 mph.

His Dart’s performance was strong, but after a year, Cam was lusting for lower E.T. slips. What’s a racer to do? More motor! Which translates to more money! So, reluctantly, Cam put the aforementioned Road Runner on the block, which meant the 383 had to be yanked out of the Dart and returned to its original residence.  The Runner soon found a new home in of Australia of all places.
With more jingle in his jeans, in the summer of 2010, Cam started the new engine project. Returning to Mayo Performance, he foraged through a mountain of 40 to 50 Mopar blocks before finding just the right 400-ci building block for his project. As with the chassis, Cam used Chrysler parts when possible, including a forged 440 Six Pack crank. The block, basically a factory bored version of the 383 with the new crank, ends up at a sizeable 451 ci. Cam’s horsepower estimate is around 550.

On New Year’s Day of 2011 at 5:00 a.m. and 15 degrees, Cam headed out on the maiden voyage of his new combination. He wasn’t alone in this madness. Two high school buds, Dave Watson and Jimmy White of Circle City Hot Rods (Jimmy’s the owner) and Jason Mayo all pitched in to help, and of course, his wife Lisa wouldn’t have missed the adventure. Cam makes it very clear that this whole project would be dead in the water without her encouragement and hands-on assistance.

Unfortunately, race conditions were less than ideal. In addition to the cold, California had been experiencing record rainfall. The track officials, in a nod to safety due to some potential drainage issues, cut the distance to an eighth-mile. Additionally, Cam experienced the as-to-be-expected new combo blues. Ignition and carb issues hampered performance. He was shooting for elapsed times in the 6.90s for eighth-mile. After three passes, one qualifying, two in competition, his best was a 7.18, which would have equated to an 11.20 in the quarter.

Cam was a bit disappointed with the end result. On the bright side, all of the rods and fluids were still in the block, the chassis and transmission handled the additional power, and the Dart, true to its nature, hooked hard and ran straight.
Bottom line, it is possible to build a strong, reliable race car in your garage with a normal array of tools and without having to sell a kidney. Cam’s $13,000 investment, including the $3,000 vehicle purchase price proves it.

P.S. Since there were some mechanical questions that went unresolved and the deadline for this was issue fast approaching, we’re going to do a follow-up to give you the scoop on the true potential of Cam’s Dart, so stay tuned. DR


Tech Sheet

Engine: Dodge
Year: 1977           
Cubic Inches: 400
Horsepower: 550                                                                                       
Torque: 500    
Built by: Mayo Performance
Crank: 440 Dodge
Rods: RPM                                        
Piston: Ross        
Comp: 10.5-1
Oil pan: Milodon
Oil pump: Melling     
Cam: COMP Cams       
Lifter: Solid    
Valves: Ferrea
Valve springs: COMP cams
Rockers:  Crane
Valve covers: Edelbrock
Headers:  TTI
Gear drive: No
Cylinder heads: Edelbrock Performer RPM       
Intake: Edelbrock 383 Victor           
Carbs: Holley 950 hp 
Fuel pump:  Holley       
Ignition system: MSD                  
Ignition wires:  Taylor       
Hoses/fittings:  Earls
Trans type:  Auto
Built by: Mayo
Performance                                                            
Converter:  Hughes   
Valve body: Pro Trans Manual            
Shifter: Hurst                              
Driveshaft: 3 inch                   
Rearend housing: 8 ¾ A-Body
Axles: Strange 35 spline
Case and gears: 489 Case Strange gears
4-30    
Rear suspension type: Super stock leak springs, Mopar
Rear shocks: Stock    
Front suspension type: Stock
Front shocks: Stock       
Steering system:  Stock
Steering linkage: Stock
Wheels front/rear:  Weld   
Wheel size front: 3.5 x 15
Wheel size rear:  10 x 15   
Tire/size front:  26x7.5x15 Mickey Thompson Sportsman
Tire/size rear: 30x12.5x15 Mickey Thompson E.T. Street       
Front brakes: Wilwood   
Rear brakes: 10 inch drum       
Chassis: Stock


DR1105-DART PHOTOS

DR-1105-LEAD

DR-1105-DART-01
Cam, his wife Lisa and the Dart, two of the most important parts of
his life. Cam, we hope you have the order right!

DR-1105-DART-02
Fittingly, a Chevy pickup being a “slave” to the Mopar, hauling it to the races.

DR-1105-DART-03
The guys who braved the elements and insanely early hour to assist Cam (Right to Left): Jason Mayo, Jimmy White (Cam’s next, lurking in the back) and Dave Watson. 

DR-1105-DART-04
Here’s Cam strapped inside the Dart’s ultra-clean, caged interior. You can catch a glimpse of the rare (read: big bucks on eBay) stock “rim blow”steering wheel. 

DR-1105-DART-05
All of the Dart’s underpinnings worked just great, it charged out of the gate and ran straight as a string.

DR-1105-DART-06
Jason Mayo and Cam check the timing on the brand-new engine.

Text by Pete Ward
Photos by Travis Noack

Source: Drag Racing

Top Fuel Bikes from Around the World Compete in South Georgia

Text and Photos by Bryan Smyth

They came from Canada, England, Germany, Japan, Norway, Sweden, South Africa and all across the United States to take part in one of the biggest all-motorcycle drag races in history.

Headlining the Manufacturers Cup event this past November at South Georgia Motorsports Park (SGMP) were the mighty Top Fuel Motorcycles; 1,000-horsepower, fire-belching, two-wheeled monsters capable of knocking down five-second laps at 240-mph-plus on the all-concrete quarter-mile.

Twelve of the Top Fuel rides were on the grounds for the Haltech World Finals, but the clear dominator was Larry “Spiderman” McBride of Newport News, Virginia, the first man to the fives on two wheels when he turned the trick back in 1999 at Houston.

McBride ran quicker through each of three rounds of qualifying to place first in the eight-bike field with a 5.83 at 237.71-mph pass. Riding for Nitro Harley legend Ray Price, North Carolina’s Tommy Grimes started second with a 6.25/236.26 and third was four-time European Super Twin nitro champion Per Bengtsson with a 6.39/212.73 on The Beast, his screw-blown, 1,700cc ride from Klippan, Sweden.

Bengtsson was the driving force behind bringing five nitro race teams from Sweden and Norway to Cecil, Georgia. He made the decision to enter the Manufacturers Cup a year earlier, and then in the spring of 2012 he began to recruit additional teams to help defray the sizable costs involved.

With DHL Global Solutions handling the logistics, worldwide shipping company Hapag-Lloyd picked up a large, ocean-going container late in September from Bengtsson’s shop in Sweden, stuffed full of each team’s motorcycles, spare parts and tools, all bound for the Port of Savannah on Georgia’s coast before reaching SGMP by truck. Once delivered to the track a little more than a month later, the container was set on the pavement in the pits and served as the Nordic visitors’ garage and home away from home throughout their race weekend.

“We have our trucks at home like you do here, but here all of our things are together, so everyone has to have some discipline about things,” Bengtsson explained. “We are all friends, too, so we work around each other, but it’s a different feeling, that’s for sure.”
Bengtsson and 2008 Super Twin champion Svein Olav Rolfstad from Skreia, Norway, had both raced in the States previously. This trip, they and most others on the visiting teams took the opportunity to include some vacation time with wives, girlfriends, family members and even a few fans from their homelands, enjoying the warm weather and Southern hospitality.
Bengtsson and Rolfstad agreed that everyone in their group was very warmly received by U.S. fans and competitors alike.

“It’s been more than fun, especially because of all the enthusiasm from the spectators. Quite a lot of them are well aware of The Beast and know about us,” Bengtsson said. “We have already said we will be back, and now we have a manual on how to do it, so it should be much easier next year.”

That’s welcome news to McBride, who said he enjoyed the competition and felt encouraged by the international presence.

“I went down there (to the Swede/ Norwegian pits) to thank them all for coming. It’s not the first time, but it’s the first time in a long time,” the American star said. “I hope a lot more foreign teams come over here to race. They’re great people, they bring some great bikes, and they’re a great addition to the show.”

Once racing began, though, the show was all about McBride. He’d already secured his second Manufacturers Cup title when veteran nitro biker Chris Hand, the points leader heading into the World Finals, failed to qualify his Redneck Express machine for eliminations, but Spiderman never faltered. In his only run in the sixes all weekend, McBride went 6.026 at 235.43 to beat Sweden’s Trond Hoiberget in the opening round, and then improved to 5.835 at 227.46 on a second-round single after North Carolina native Tii Tharpe’s bike broke on the launch.

That set up a final-round faceoff for McBride against Rolfstad, who previously dispatched Bengtsson from round one and also made a solo pass in the semis when Texan Rickey House was unable to continue.

Unfortunately, it was Rolfstad’s turn to have trouble in the final, when his team discovered a leak from the engine at the end of his burnout. McBride then ran his best pass of the weekend with a 5.829 at 222.47 mph to take the win and officially wrap up his 11th career championship.

“You hate to see somebody break like that, especially when they came all the way from Europe to race, but at the same time, it does take a lot of the pressure off,” McBride admitted. “We had it hopped up there for the final, but we were having some cylinder-dropping problems, and I actually clicked it off early, but even with that it still was running extremely quick.”

Manufacturers Cup co-managers and promoters Jay Regan and Dave Schnitz were obviously very pleased after more than 800 tech cards were turned in for the third and final event of the 2012 series, but even more so with the trend toward foreign participation.

“It started with several race teams just coming as fans,” Regan explained. “But this year a lot of them wanted to step it up and come race with us, so we helped them with logistics and transportation and just tried to make it as easy and inviting as possible for them to compete.

“We think it adds a tremendous flavor to the event, so we’re actually going to try and further that by working collectively with the FIM/UEM, the European drag race sanctioning body, and see if we can turn this into a true world championship effort,” he added. “That would be the best possible scenario.”

DR-1303-BIKE Photo Captions

DR-1303-BIKE-LEAD

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Larry McBride dominated: He qualified first, set Low E.T./Top Speed and captured his 11th championship and second Manufacturer’s Cup title.

DR-1303-BIKE-02
Swede Trond Hoiberget of Super Twin Top Fueler fame glows eerie green on his launch.

DR-1303-BIKE-03
Four-time European champ Per Bengtsson unleashes The Beast, his infamous nitro parallel twin monster.

DR-1303-BIKE-04
Tommy Grimes riding for the legendary Ray Price Racing out of his HD dealership in Raleigh, NC.

DR-1303-BIKE-05
Rickard Gustafsson, a member of the Swedish Fuel Bike "Mafia"

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Chris Hand led the points coming into the race, but his Redneck Express failed to qualify.

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Iyo, Ehime, Japan-based Top Fuel rider Takeshi Shigematsu is a regular on the U.S. Nitro Bike scene.

DR-1303-BIKE-08
Texan Ricky House won his first round pairing, but got a no-show for round two.

Stop It! Brake Safety Tips for Drag Racing

The braking systems in various forms of racing differ significantly.  Dirt cars, such as sprint and late models, vary greatly from asphalt vehicles, such as road race and NASCAR.  Drag racing is especially unique and has its own special requirements.

Pedal Design—A properly designed pedal or handle will maximize line pressure, eliminate binding and increase brake torque.

In most forms of motor sports the repetitive use of the brakes creates a significant heat buildup. The longer the event, the greater the buildup, hence rotor and caliper size, pad compound and other factors take on significant importance. The type of racing also impacts which elements take on added importance.

In drag racing brakes have been an overlooked element for far too long.  Recently, several factors have become apparent, forcing this oversight to be addressed seriously. Most drag racing tracks were built in the ‘90s, ‘80s or even earlier when speeds were dramatically lower. Shutdown areas, as you can imagine, were much shorter. Combine that with the tech requirement for parachutes over a given speed, and brakes were considered important for staging and little else. Much has changed in the past few years, and there have been serious consequences as a result, forcing an examination of the brake requirements to return maximum safety to the sport.

Let’s examine brake system and see how various components affect the overall performance of the system as it relates to drag racing. First, we begin with the input force. This relates to the driver either stepping on a pedal or pulling the brake lever to actuate the master cylinder to create line pressure. This line pressure is then moved through the brake lines to the calipers to create clamping force. The clamping force acts on the brake pad to clamp the rotor, which, in turn, slows the tire from turning through friction with the track surface.

Here is a close-up of proper pedal design

That all seems pretty simple and should provide a steady, predictable stop, but let’s take a look at what happens when various components are either left out or fail to do their job.

Input force is generated through a pedal or lever, all of which have a ratio.  This ratio is the distance from the pivot to the center of the pedal/handle, compared to the distance from the pivot to the master cylinder pivot. This ratio acts in unison with the master cylinder bore size to create line pressure. Line pressure is what makes the caliper work. The higher the line pressure to the caliper, the harder the caliper works. Well, you might be wondering if it’s that simple, why don’t we just dump more pressure into the caliper to make it work harder? The answer to that question is simple physics. We are limited by the travel of the pedal/lever and the size of the master cylinder. In the formula, line pressure equals input pressure multiplied by pedal ratio divided by the surface area of the master cylinder. We can only go as small on the master cylinder as the caliper requirement for fluid.

Pedal Ratio—To obtain pedal/handle ratio, measure from the pivot point to the center of the pedal pad/top of the handle (dim A). Then measure from the pivot point to the attachment point of the master cylinder pushrod (dim B). Divide B in to A for pedal/handle ratio. Pedal/handle ratio affects input of force, line pressure and stroke

To clarify, when you step on the pedal with 100 pounds of force (which is quite easy to do when you are sitting down) multiplied by the 6:1 pedal ratio, you have 6 multiplied by 100 pounds or 600 pounds of force on the master.  If the master cylinder bore size is 1 inch, the surface area of the master is .785 square inch. Dividing 600 pounds by.785 square inch theoretically yields 764 pounds of line pressure. If you have a particularly rigid caliper, then you have the ability to reduce the master cylinder bore size since the caliper will not require as large a volume of fluid as a more flexible one. In this example, a 7/8-inch master cylinder, which has a surface area of .601 square inch, with all other factors remaining the same, will up the line pressure to 998 pounds from the 764 pounds previously noted. The final element of the equation for torque is the coefficient of friction, or Mu of the pad. Pad coefficient of cold friction can vary from .3 to .6 or more, depending on the materials and operating temperature. More on this later.
Normally, the resultant torque from even the lower line pressure would be sufficient. However, other factors in the system reduce the actual pressure due to various conditions, such as frictional binding in the pedals, growth of the brake lines, bending or flex of the calipers, etc. Hence, there is a limit to how small the master cylinder size can be, which limits line pressure. This is why your choice of components is so critical.

For example, plumbing your car entirely in braided line will increase the fluid requirement proportionally for every inch of braided line in the car, as it will swell far more than solid line. This also causes a “hysteresis” effect, meaning there is a delay in the very important release characteristic of the caliper.
When you combine this delay with the fact that most calipers flex, the resultant drag caused by this delay discourages anyone from running an extremely critical valve.  This valve is called a residual valve. Its purpose is to maintain residual line pressure so that the calipers are ready to react on the next application. Because the master cylinders on drag cars are often mounted below the height of the caliper position, brake fluid will roll back downhill to the caliper while the car is traveling down the track. Combined with the severe vibration found on the higher horsepower vehicles, there is a disastrous loss of fluid in the proper area of the system at a critical time (at the finish line and shutdown).

Racers often try to overcome this problem by simply mounting the reservoir above the height of the caliper to stop the fluid rollback. This alone will not stop the serious vibratory effects on high horsepower cars. The fluid will still move away from the caliper itself.  A properly functioning residual valve is a key component in the brake system.

Consider that the rotor does not stop the car. The rotor is a heat dissipater and a lever only. If the caliper is unable to clamp the rotor, then it makes little difference what material or what diameter it is. If you are converting to carbon, please note there is drawback to carbon rotor/carbon pad systems that merits consideration. Carbon parts have very poor cold friction and require warming.  This could cause low torque and a resultant line creep, when attempting to stage the car. It also means that there will be a delay in the deceleration rate at the finish line due to the time it takes for the pads to come up to temperature to increase the torque. A good comparison of this principal is the torque output of an engine getting better as it approaches its optimum rpm.

A finish line speed of just 200 mph is 293 feet per second. At this speed a vehicle can travel more than 1,000 feet through shutdown in four seconds. At 300 mph, feet per second increases to 440.  This means that in three seconds, [i]if you apply the brakes exactly at the finish line[/i], you will travel ¼-mile or the equivalent of the race in less time than it took you to get there! On tracks where every foot of shutdown area is critical, this clearly could create a disastrous condition.

Since the key component of the brake system is really the caliper, it is important that this component be capable of the demands placed upon it. As a guideline, if you can see the caliper flex during bleeding, your caliper is too weak. A simple way to verify is to use a pair of vernier calipers over the center of the brake caliper and have someone step on the brake; flex of more than .020 is an indication of an inadequate caliper. The aforementioned combined with the loss of clamping force from weak calipers flexing (thereby wedging the brake pad into the rotor) results in a major reduction in deceleration rate. This wedging of the pad due to flex also creates inconsistent application, causing bounce or shake, which reduces the contact patch and time and increases stopping distance. This actual rate of deceleration is far different from what the basic line pressure math in the beginning of the article would indicate.
Simply inserting an exotic brake pad with a high Mu does not fix the larger problem; it is only a single factor in the equation. In many cases, this high torque level is only achieved at high temperatures, and low temperature performance degrades accordingly. There is no single magic bullet that can cure the ills of a weak or improperly designed brake system. All facets of the system must be designed to work in concert.

Obviously, all components of the system must be in proper operating order to provide a safe system. The factors discussed in this article are offered as a guideline to help ensure that the potential pitfalls are dealt with so that when you need the brakes, they will be there.

For years, racers have either used components based on price and weight alone, or failed to monitor the condition of the components of the system and gradually allowed the points listed above to reduce the overall effectiveness of their brake system. Most drag racers running high-speed cars place the bulk of the requirement of stopping the car on the parachute. Do not be misled! Every car, even over 300 mph, should be able to make a safe and complete stop with no parachute at all, on every pass. Parachutes often deploy incompletely or fail to open at all. This alone should alert us to the importance of the previous statement. A good brake system can make you a better racer, improve your 60-foot times, save your equipment from potential disaster at high speeds and most importantly, save your life. Don’t settle for less.
 
This article is copyrighted by The Brake Man, Inc. The information presented or any part hereof, may not be reproduced in any form without the express written consent of “The Brake Man, Inc.”

Text by Warren Gilliland
Photos and Illustrations Courtesy of The Brakeman, Inc.