The valve train is pulled and the camshaft and lifters are inspected. The insides of the cylinders are examined with borescopes inspects the interior using mirrors. The cylinders are pressurized and the rate of leak down is measured to see how well the pistons and seals hold the pressure. All of the lines and hoses are checked. Only after all of these tests and inspections are finished is the engine ready to go to the races.
Insuring the reliability of the engine is critical -- almost any engine failure during a race eliminates any chances of winning.
Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. And the block itself is designed with lightness in mind, at the expense of long-distance durability. Geometrically, the camshaft sits high in the valley of the V to shorten the length of the pushrods and to leave more space around the crankshaft for air to move freely.
The camshaft fits into a cast-in tunnel that separates it from the crankcase to prevent oil from dripping off the cam and onto the crankshaft, according to Simon. Even the racing block's material is different. Production blocks, formerly cast iron, are now mostly aluminum to save weight.
But Nascar mandates that the race engine block still be made with iron. Race-engine builders comply by using the strongest kind of iron they can—compacted graphite iron. Because weight is more important than longevity, race engines forego stiffness for mass. As a result, these blocks flex and bend under the stress of their work, according to Patrick Baer, supervisor of Dodge Motorsports engine programs.
A production engine designer would look at a race engine and say that part will never live. But to make something really stiff, you have to add structure, and structure is weight, and weight is not the friend of the race engine. In your car's engine, extra oil collects in what is essentially a bucket under the crankcase after it drips off the parts it is lubricating.
From there, the oil pump pushes it back up through the passages in the block, and it starts working its way back down again. That's fine for your car, but in a racing engine, all that sloshing oil robs the power that Dale Earnhardt Jr. Racing engines use a dry sump system, which catches oil as soon as it reaches the crankcase. Oil is then sucked out of the engine by the externally mounted pump's scavenge stage and sent to an oil tank.
Keeping oil in an external tank allows the whirling and reciprocating parts of the crankcase to move through clean air, boosting power by as much as 10 or 20 horsepower, according to David Currier, vice president of engine engineering for Toyota Racing Development.
Each Toyota racing engine is built using blueprinting, a process that ensures all engine components are within the parameters set by NASCAR's governing body. Once the engines are built, Toyota Racing Development tests the engines using a device called a dynamometer, which measures horsepower and torque.
This allows the engine developers to monitor how the engine holds up under high RPM. Today, Chevrolet supplies engines for thirteen racing teams. Oil plays a big role in the performance of the R07 engine.
Oil is used to cool and dampen parts of the R07, as opposed to older Chevrolet engines that relied on oil simply for lubrication. Compared to the SB2 engine, the R07 engine's camshaft is located higher in the block, meaning that valvetrain dynamics are improved at high RPM. The R07 is capable of operating at 10, RPM. Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe.
Prev NEXT. Auto Racing. By: Karim Nice. The engine is large -- cubic inches 5. Not many street-cars have engines this big, and the ones that do usually generate well over hp. NASCAR engines have extremely radical cam profiles that open the intake valves much earlier and keep them open longer than in streetcar engines.
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