Chris Paulsen— C&R Racing, Inc.
Designing and Optimizing Cooling Systems for Performance and Durability
Cooling systems are often overlooked in short-track racing, but Chris Paulsen from C&R Racing stressed not only the importance of a good radiator, but the entire cooling system. Chris’ discussion was based around cooling system design, with a focus on pressurized cooling systems. While these types of systems are the norm on Cup and ARCA cars, the technology is slowly trickling down into the Super Late Model ranks.
Aside from cooling the engine, Chris also discussed airbox design. He talked about how important the inlet shape was and the design of the box to ensure the incoming air slows enough before it hits the radiator to sufficiently cool the water in the system. Airboxes for both asphalt and dirt were discussed, specifically the floor design. For an asphalt car, getting as much air into the airbox is key. The air can have a direct path to the radiator, because not much debris will enter the box. For dirt, on the other hand, the floor of the airbox needs to have a hump in it so there is no direct path to the radiator. This hump stops any dirt and debris from becoming lodged between the fins of the radiator.
Chris also talked about core design, coolants, and the effect straight water has on raw aluminum. His presentation was very intriguing, and you can most likely expect an in-depth story on cooling systems in a future issue of CT.
Vincent Roman— Burns Stainless LLC
Development Tools and Testing Methods for the Optimization of Exhaust Performance
Engines are nothing more than air pumps. The more efficiently you can move air through the engine, the more power it can make. Vincent Roman of Burns Stainless presented about the processes the company goes through to design and test exhaust system for optimal power.
When Burns Stainless designs an exhaust system, they look to maximize the power band without sacrificing maximum power. They do this by optimizing the header primary tube length to the upper range of the rpm band of interest. They also optimize the collector design to provide good midrange torque. And they optimize the tailpipe to maximize the flow of exhaust gases. This is accomplished by looking at the Ideal Gas Law, incompressible and compressible flow, head loss (friction loss), and the Four Stroke Otto Cycle as the technical concepts for design.
Burns also spends a lot of lime looking at the area of the exhaust system. With stepped headers and transitions from collectors to exhaust tube, the area of the exhaust system changes. Because of this pressure, wave dynamics come into play. Increases or decreases in size will cause pressure waves within the exhaust system. The system can be adjusted and sized properly to take advantage of the positive pressure waves and reflection rarefaction waves to optimize the exhaust system. While wave tuning is not a new concept, it is essential in optimizing an exhaust system for maximum power in a specific rpm range.
How to Use Cylinder Pressure and Valve Motion Measurements to Improve Performance
Cecil Stevens came to AETC to present on cylinder pressure and valve motion. His discussion started with some background and went into Lunch Box Joe and Professor Kofferman’s testing procedures for cylinder pressure. He talked about cylinder pressure measurements as the continuous recording of cylinder pressure every crankshaft degree. Lunch Box Joe’s testing requires a dyno (must hold plus or minus 25 rpm), a test engine, pressure transducers, a crankshaft encoder, a data acquisition system, analysis software, and a computer. What this system cannot report is individual, cylinder vs. cylinder, or cycle vs. cycle performance. He then went into each part of the system, explaining how each part works and the procedure for testing.
The second section of his presentation discussed camshaft profiles, valve events, and engine cycle events, addressing how each related and affects cylinder pressure. Valvespring pressure and valve bounce, as well as their effect of performance also were covered.
Bill McKnight— Mahle Clevite, Inc.
The Science of Bearings and How They Can Be Optimized to Maximize Performance
Bearings always seem to be a hot topic of discussion with engine builders. When Bill McKnight from Mahle Clevite took the stage, people’s ears perked up. Bill started his presentation by saying his job as an educator is to make complicated stuff simple.
Over the next hour, Bill discussed the lubrication challenges of bearings, the balancing act of characteristics of hard and soft bearing, bearing trends in the OE world, the bearing material portfolio, and he talked about bearing coatings. Bill explained the differences between hydrodynamic, boundary, and mixed lubrication for bearings. It was very informative, made for some great discussions during lunch and the breaks.While this seems like a lot of information (and it is), it’s only the tip of the iceberg as it is all you can fit in an hour-long presentation.
Stephen Golya and Dane Kalinowski—JE Pistons
The Design and Analysis of High Performance Rotating Assemblies
Stephen Golya and Dane Kalinowski from JE Pistons were tasked with speaking to the group about the latest in piston technology. Both are on the JE engineering team, with Golya being the Principal Engineer.
The duo discussed many things including JE’s design philosophy, its analytic methods, piston material choices, and manufacturing processes, as well as the company’s quality management and dyno testing capabilities.
The team talked about the development of JE’s SBC LSX 912FRL piston, as well as the billet vs. forged piston debate. The pair talked about the pros and cons of each piston type, including the manufacturing process and the machine used to produce each.