Clarifying piston balancing with a few words from Kaase

Clarifying piston balancing with a few words from Kaase

By Titus Bloom: “It’s hard for me to be persuaded on the merits of piston balancing,” said a leading oval track engine builder recently. “While operating, the piston is being thrust up against one side of the cylinder wall,” he continued, “wedged in one direction on the even bank and in the opposite direction on the uneven bank. Besides, there’s the action of the connecting rods, their weights, their lengths and where they’re connected to the piston. Then, you might consider combustion forces, and piston domes being assaulted by wedging forces—to say nothing of the degree of tumult in the crankcase. I think you’re splitting hairs,” he argued convincingly. “Fine piston balance is neither here nor there.” But from a piston maker’s approach, there are two types of balancing. First, the conventional balance is used to reduce the prospect of significant piston weight variation in large-bore engines. The objective is to maintain bearing loads within the design range, that is, main bearing loads, as they are the focus of engine crank balancing and also of vibration levels. In addition, crank pin and piston pin loads must also be held within their respective design loads. So, in truth, these efforts are more focused on durability than performance. This is why some engine builders see little value in it. However, certain engines will be more sensitive to piston weight variation than others, so it can be important for engines where bearing capacity or vibration levels are reaching their upper limits. The second type of piston balancing is embraced by those engineers ardently seeking any slight advantage and involves manipulating the mass distribution of...
Vintage class winner: EMC attracts unexpected 600,000 views

Vintage class winner: EMC attracts unexpected 600,000 views

By Alfie Bilk: Jon Kaase has won this year’s Amsoil Engine Masters Challenge Vintage class with a 473ci 1958 MEL (Mercury-Edsel-Lincoln) engine. Exploring the classic turf in distinctive fashion, it was not the first time Kaase had arrived with an unorthodox relic endowed with bewildering technology. Held annually in early October at the University of Northwestern Ohio, his entry produced 770hp with torque never less than 630lb-ft during the entire scored rpm range of 3,700-6,200rpm. The engine’s peak torque was recorded at 715lb-ft. Earning a check in the sum of $13,700, it was Kaase’s seventh victory at the prestigious affair, which coincided a few days before his sixty-fifth birthday. This year’s Vintage rules specified factory cast iron cylinder heads and prohibited welding or the application of epoxy to the ports. Also, it was stipulated that the engine block must retain its original bore spacing and original block deck angle. A further constraint for Kaase was the fact that he had to return the MEL block to its owner, Royce Brechler, in a functioning condition. The origins that preceded the workings of a bright mind MEL engines had wedge-shaped combustion chambers formed between a flat cylinder head surface and an angle-milled block deck angle that was ten degrees off square with the bore axis. The piston crown determined the compression ratio and combustion chamber shape—a concept similar to Chevrolet’s 409, a design also introduced originally in 1958. Yet to each cylinder head deck, Kaase added four slugs of round bronze bar stock by counter-boring the heads to accept them. Measuring 4.600in diameter and 1.250in tall and protruding downwards, each set...
Artful Dodgers: How crafty racers succeed

Artful Dodgers: How crafty racers succeed

By Alfie Bilk:   “I once saw a nitrous oxide system concealed within a brake booster,” says Nitrous Supply’s Mike Thermos. “The illicit charge was transmitted by way of the vacuum line and into the intake manifold. Another bamboozle I recall prevailed by delivering nitrous through the heater hoses.” Twenty years ago, Rusty Glidden shook the drag racing establishment when he admitted illicit use of nitrous oxide in his Pro Stock Ford Probe. His father, Bob, had exhausted the NHRA’s patience with repeated accusations of nitrous use in the class, causing the sanctioning body to react. Accordingly, NHRA’s then senior VP, Graham Light, vigorously denied the allegations, proclaiming them as nonsense and fiction. Then Glidden’s son, Rusty, presumably in an attempt to defend his father’s reputation and in so doing ruining his own, confessed that he, in fact, had been an offender, thus conclusively proving the point. According to racers from that era, Rusty also harbored deep suspicions of wrongdoing in Pro Stock and had urged the NHRA to investigate but had achieved not a thing.  In the end, he left no doubt as to how the deceit could be perpetrated, disclosing full technical details in the magazine Super Stock published late in 1995. It defined in unambiguous detail how the weight bar at the rear of the car had served as the nitrous holding tank. “The nitrous line started there,” Super Stock reported, “went over the rear axle housing right up to the front. It ended at the motor plate, which was rifle-drilled. One of the supports holding the hood scoop was also rifle-drilled. This tall slender rod...
Best innovation for drivers obliged to carry ballast

Best innovation for drivers obliged to carry ballast

Earlier we published a story explaining the function and benefit of the tuned mass damper to the racer. This device received much of the credit for winning the 2005 Formula One World Championship for Renault. So successful was its implementation it was banned. Still, the technology remains relevant and incorporating the device would benefit any racer who is obliged to carry ballast. Equally interesting is the story’s reference to the use of lead shot for ballast—a technique that damps all frequencies, but with only half the effectiveness of a tuned mass damper of the same weight. Here is the story by its chief protagonist, Dave Hamer.    By Dave Hamer: In my previous article, I covered the successful use of the tuned mass damper on F1 race cars. The principle of the TMD is similar to that of a harmonic damper on an engine, which is used to reduce crankshaft torsional modes. Similarly, some convertible sports cars use weights in the front bumper, which are tuned to reduce scuttle shake. Triumph TR6 and TR7 used them, I believe. Our TMD story goes back to the late 1980s where a 7-post rig was the principal tool for tuning the suspension on our active-suspension cars. This rig uses hydraulic actuators to introduce four vertical movements to the tires to mimic bumps and three forces into the chassis to mimic aero and inertial loads. Before we went to the complexity of track replay we would use a swept sine input. A sine wave played into a 7-post rig produces a smooth up-and-down movement (like the piston movement in an engine). The swept...

World’s first sequential retrofit transmission for Corvette:

By Ben Mozart –  Photos by Moore Good Ink: Reece Cox is a man who immerses himself in details. For nineteen years he has served Corvette and Camaro owners, supplying them primarily with race parts. In the early nineteen nineties, he functioned as crew chief at Morrison Motorsports, running the Mobil 1 Corvettes. Now he is introducing the world’s first sequential retrofit transmission for the Corvette and all others with front-mounted Tremec T-56 transmissions. The purpose of his new gearbox is simple: gear shifts are executed in 10 to 20 milliseconds. Camaro, Mustang, Viper—in fact, conversions for all front-mounted Tremec T-56 transmissions soon to follow Marietta GA: MTI Racing has pioneered the world’s first 6-speed sequential transmission for C5 and C6 Corvettes. Operating in the stock transmission casing, its chief purpose is to accomplish exceedingly fast no-lift clutchless shifting. A direct bolt-in dog-engagement transmission, the service will soon extend to Camaro, Mustang, and Viper—in fact all front-mounted Tremec T-56 and T-6060 transmissions. Using the original Tremec gear case, MTI converts the internals and the H-pattern shift mechanism to full sequential operation. Introduced initially for the Corvette, it maintains the original mating surfaces and operates with the original mountings, clutch, slave cylinder, and drive-shafts. Its two key advancements are its strength and most of all its shifting speeds. Shift times with the original equipment require about a second. With dog engagement shift times are reduced to 0.30 to 0.40sec, depending on shift lever ratio. But when accompanied by an electronic paddle-shift mechanism, this dog-engagement design will affect a shift in 10 to 20 milliseconds (100th to 200th of a second). But...

How the racing slick was born

By Ben Mozart Photography courtesy of Jim White When Tom “the Mongoose” McEwen, now 76, speaks of racing you are often struck by his power of recall and his perceptiveness, which is never more apparent than when he gets on the subject of race tire development. “The only reason we have tread on a tire,” says McEwen, “is to allow us to drive in the rain. As drag racing isn’t conducted in the rain, we would put our tires in a lathe in the early days, back in the 1950s, and we’d cut off the tread in an effort to put more rubber on the track.” Though shaving off the tread gave the early racers greater contact area it also created a problem: the rubber between the bottom of the treads and the top of the cords wasn’t always consistent. Invariably it was much too hard. Then in the mid-nineteen-fifties, a company called Bite by Bruce who produced recap tires in Arizona for road vehicles and represented by a most menacing logo, introduced the first tire with a slick surface. According to “Mongoose” McEwen, these recaps represented the origins of the modern racing slick tire. Before Burn-outs “In the old days before the practice of burnouts,” McEwen recalled, “when the cars approached the starting line, mechanics would soak rags in gasoline and wipe them around the circumference of the slicks in an attempt to soften the rubber and thus make the tire grip better.” Then in 1957 in Watertown, Massachusetts, Marvin Rifchin with his father Harry of M&H introduced the first dedicated racing slicks. Initially these offered less than...
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