Judson Massingill, School of Automotive Machinists (SAM)
"Building Big-Inch LS Engines for Maximum Performance"
A legend in his own time, Judson Massingill started out as a successful racer and engine builder before founding the School of Automotive Machinists back in 1985. This is a modest man who has, to use a catchphrase, forgotten more about engines than most will ever know. His years of experience yielded a presentation so chock full of information, it would take attendees days, if not months, to fully mull over and digest.
Delivered in a "food for thought" style, Massingill began with a discussion of factory and aftermarket blocks and how to modify them for large cubic inch duty. Some interesting tidbits included the fact that doweled main caps are more important than their being billet, and that one of the main concerns with long strokes is that the pistons begin to exit the bottom of the block; each block has a different cylinder length to work with. As to rotating assemblies, discussions included the appropriateness of turning down of stock cranks to Honda rod journal sizes, the power and RPM capabilities of various LS connecting rods, and how forged pistons are a no-brainer upgrade for a big-inch engine (along with a discussion of the pros and cons of 2618 vs. 4032 aluminum forgings). Massengill could not emphasize enough how important the ring package is, stating that it can amount to 15 percent of the engine's horsepower. He also gave a nifty graph of the sources of friction in an engine, and it was clearly demonstrated that pistons and rings are the largest contributor, with bearings being the least significant culprit. Much discussion was had of ring material, design, and gap.
With his talk moving on and spanning topics from cylinder wall finish requirements to camshaft sizing secrets to cylinder head port sizing, we could not even begin to summarize the amount information he gave us--his presentation was easily one of the most valuable and most-discussed of the conference. His final statement was perhaps most telling of what it has taken to become so knowledgeable: "the guy standing on the biggest pile of parts that didn't work is usually the race winner!"
Billy Godbold, COMP
"How Current LSX Development Makes Today the Most Exciting Time for Valve Train Design"
With a masters in physics under his belt, Billy Godbold has designed camshaft profiles for engines seeing duties spanning street performance to NASCAR, IRL, and endurance racing, to name but a few. The topics covered in his presentation were varied and all were helpful to the LS enthusiast.
Godbold started off with a discussion of LS cam designs and techniques, touching on the various series of camshafts offered by COMP and how their profiles vary by design. Dyno and Spintron development was the next area covered by his talk, and Godbold made clear that the LS platform has been by far the most tested engine at the COMP facility in recent years. For readers who don't know what a Spintron is, it's quite a sight to behold in person: it essentially consists of an engine block that has a hole punched through one cylinder of the block (which also operates sans piston) such that valve movement can be measured using precision equipment as the engine is spun using an electric motor. Not only does this allow verification that valve motion stays within specified ranges of control at all rpm ranges, it also allows simulated circle track, drag race, and road race torture testing to ensure valvetrain strength and longevity.
Computer modeling of valvetrain components (including valvesprings) was also discussed, including how a virtual Spintron test can be conducted prior to making parts in order to shorten development time. Also, verification that the computer model accurately correlates with physical behavior in the real world must be conducted regularly in order to ensure the software is being utilized to its fullest extent. Finally, Godbold highlighted the huge average power and torque gains COMP is seeing from the use of camshaft phaser technology, detailed how the factory VVT system works, and demonstrated COMP's newly released phaser limiter system for LS engines. He discussed the challenges that have been overcome, and the tremendous benefits resulting from the use of, camshaft phaser systems in high-performance LS engines (use of VVT-specific COMP cams have shown the biggest power increases without sacrifice in the history of the company!). We're sure all AETC attendees were convinced that far from an unusable factory feature, VVT is the wave of the future for LS engines even as aftermarket high-performance goes!