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13th Annual Advanced Engine Technology Conference
By Ken Weber
For most of my adult life, I have wished that I could have access to the "inner sanctum" of engine building and automotive technology. Then I could get a good look behind the door, talk to the movers and shakers, find answers or opinions for those "what if", or "how do I", questions that always pop up in the middle of a project.
Five years ago I started attending the Advanced Engine Technology Conference (AETC) in Colorado Springs, CO, hosted by Superflow, and discovered that this is the "behind the door place" I had been seeking.
The format of the conference is a program of formal presentations covering a wide range of primarily performance engine related topics, woven into a four-day setting that puts movers and shakers of the automotive world together, and maximizes the networking opportunity that those of us less knowledgeable types can utilize to its fullest.
Where else can you get the undivided attention of Joe Mondello to answer your questions on air flow, or ask Myron Cottrell a question about EFI systems, or benefit from the experience of Bob Keller of Turbonetics to solve your turbocharging problem, when they are not busy with a hundred other demands on their time?
Over the past five years, I have personally benefited from conversations with and advice from, the likes of – Harold Bettes, Superflow; Joe Mondello, Mondello Technical School; Billy Godbold and Thomas Griffin, Comp Cams; Richard Maskin, Dart Machinery; Dr. Dean Hill, professor of chemistry at New Mexico State University; Harold Martin, Martin Motorsports; John Havel, Clevite Engine Parts; John Erb, Keith Black Pistons; Darin Morgan, Rher-Morrison Racing Engines; David Vizard, journalist/engine builder; Keith Wilson, Wilson Manifolds; Ron Sperry, GM Motorsports; and Joe Sherman, Sherman Racing Engines – just to name a few.
Literally hundreds of others have contributed bits and pieces of information that continually push back the fog that obscures my understanding of the internal combustion beast I wrestle with from day-to-day. The stack of business cards I have collected from the conference is over three inches tall! In addition to that, every year AETC supplies an attendance list with addresses, phone numbers and e-mail addresses. The formal presentations are well worth the cost to attend, but the opportunity to meet one-on-one with the people that "do it" in this industry is priceless.
This year, the four-day event started on Thursday with hands-on training sessions at Superflow’s headquarters in Colorado Springs, CO. The sessions were conducted on the Cycledyn and Autodyn chassis dynamometers. And there were two seminars on maximizing your business with a flow bench and a dynamometer given by Superflow’s Harold Bettes.
Friday’s program opened with Bob Keller of Turbonetics, on the advantages of turbocharging vs. supercharging. A holder of multiple patents and SEMA’s 1993 "person of the year", Keller opened his presentation by covering some basic information on the various types of superchargers. He explained that a roots blower is a pump, not a compressor. It creates boost by moving more air than the engine needs, thereby creating boost.
By contrast, a centrifugal supercharger actually compresses the air as it moves through the supercharger, and therefore is significantly more efficient. The higher efficiency results in less temperature rise, and therefore more power for any given amount of boost.
Keller used an example of two 500 hp installations, one with a supercharger and one with a turbocharger, to illustrate the turbo’s advantage. In a good turbo installation, the exhaust back-pressure is equal to the manifold pressure (called crossover), and crankshaft horsepower isn’t required to turn the impeller.
In a supercharger, crankshaft horsepower is required to create the increase in manifold pressure, plus there is always a parasitic loss in the drive mechanism. In the demonstration engine, the turbo’s advantage was 52.9 hp over the supercharged engine. The bottom line is that a supercharged engine must always produce more internal power to equal the flywheel power of a turbocharged engine. And with the new ceramic ball bearings used in turbochargers these days, the dreaded turbo lag is, for all practical purposes, a thing of the past.
Friday’s second presentation, "Product Engineering from Concept to Completion," was presented by John Satterfield, owner of DAM Machine Shop in Poughkeepsie, NY. He is a holder of several patents for fuel emulsion systems for Holley carburetors
Satterfield’s presentation pointed out the importance of designing an engine project from the beginning, in order to achieve the desired horsepower. Once the engine size and horsepower are determined, then you can calculate the required port areas (flow velocity), rpm range, and bore/stroke/rod geometry (piston speed and position-vs-crank angle).
The balance of the presentation focused on intake port geometry and liquid flow requirements: "Think like a droplet of fuel," and how port shape, orientation to the bore, and the position of the piston can help or hinder droplet motion.
Dan Agnew opened the first afternoon session with the design and manufacture of composite intake manifolds. Agnew is a former engineer for the GM powertrain group (’83-’99), and has worked on projects such as the new inline six-cylinder engine. He is a previous presenter at the AETC conference, and is currently employed with Managed Programs LLC.
The history of manifold materials started initially with cast iron, then cast aluminum, and ultimately led to a variety of composite technologies. Cast composites offer half the mass of cast aluminum, lower heat conduction, smoother surfaces and potentially lower costs. The lower mechanical properties of composites require a different approach to structural design, and the composites transmit more noise that has to be dampened (I presume only if noise is a consideration).
Composites are becoming more attractive because experience with the materials is increasing and manufacturing techniques, such as injection molding and vibration welding, have reduced the cost of manufacturing, while at the same time increased the quality of the finished product. Agnew had several composite products on display. And when you pick up an intake manifold and almost throw it through the ceiling because it is so light, you begin to appreciate why Detroit is looking so hard at this technology.
Closing out Friday afternoon’s presentations, Dave Guerrieri, a research scientist with the Bureau of Mobile Sources for the state of New York, made a "Brief Discussion About Failure." Guerrieri received his M.S. in Mechanical Engineering from the University of Michigan, with an emphasis in "Fracture Mechanics and Fatigue," and has been involved in racing for more than 30 years.
Guerrieri made some key points for those of us unlucky enough to have to determine "why it broke." First, you start with careful disassembly, looking for clues as you go, and documenting your findings. Don’t force broken parts back together. This destroys the possibility of microscopic analysis of the fracture zone and makes it impossible to determine the cause of the failure. Preserve the evidence by cleaning the fractured area with a good solvent, and then protect it with clean oil or spray with lacquer. Finally, have a metallurgy lab look at the pieces.
Saturday’s opening presentation was by Dr. Dean Hill, Ph.D. Chemist, professor of Mechanical Engineering at New Mexico State University, long time drag racer, and the originator of H&H racing gasoline. A veteran speaker at AETC, Dr. Hill’s presentation on "Gasoline: Structure and Combustion" was probably the most entertaining event of the conference.
Dr. Hill began by explaining the nature of carbon chains and the progression from a simple carbon atom, to Methane (CH4), Ethane (C2H6), Propane (C3H8), Butane and Isobutane (C4H10), Pentane, n-pentane, Isopentane, and Neopentane (C5H12), and finally Asphalt (C40H88), which has some 62 trillion isomers.
Once the basics were down, we learned the nature of octane ratings. Even if you don’t know anything about the chemistry of gasoline, I’ll bet you’re familiar with octane ratings. Did you know that, technically, octane ratings stop at 100? Dr. Hill explained that octane numbers above 100 are really just performance numbers, and are determined by the ml/gal of tetraethyllead (TEL).
For example, a gasoline that has the same critical compression ratio of pure iso-octane with 3.2 ml/gal of TEL, would have a performance number of 116. So what’s the best gasoline? Try triptane with 6 ml/gal of TEL. It only costs $5,000 per drum, but you could run a supercharged engine with 16:1 compression on it without detonation.
The lesson (chemistry 341) concluded with a look at various types of racing fuels, including NITRO. Dr. Hill had to pay up on that one because Harold Bettes wagered that he couldn’t get through the talk without using the "N" word!
Leonard Warren, President of Tech Line Coatings Inc., was the second speaker on Saturday, and he let us in on some of the advances in coating technology. Tech line supplies products for production applications with major OEMs in the US, Europe, and Japan, and has developed an exterior coating for the X30 Space Plane, which was being developed by McDonald Douglas.
Recent developments in coatings make them suitable for a wider variety of applications that were not possible before. One such example is the coating of the inside of a wheel with a thermal barrier to reduce the effect of brake heat on the tire. Today’s coatings have higher temperature capabilities, reduced film thickness, increased lubrication capabilities, chemical and corrosion resistance, and a reduction of hazardous ingredients. The applications are only as limited as your imagination, and formulations are now available that the average shop can apply in house.
After lunch in the hotel atrium, and some more networking, Billy Godbold, of Comp Cams discussed "Optimizing Valve Events to Improve Performance". After a lesson in the terminology used in camshaft design (including snap, crackle and pop), Billy used a typical NASCAR Busch profile to illustrate the effects of change such as advance and retard, increasing or decreasing lash, and changes in duration and lobe separation on the dominant exhaust open and intake close events.
Godbold then carried the exercise deeper by showing how individual sections of a profile can be optimized to change valve events without a change of area. In other words, a faster lift rate on the opening side can be used with a later opening event, or vice versa, and the same on the closing side. When you have to tune cam timing to the Nth degree, you have to use a variety of techniques to optimize valve events. The difficulty in this exercise is determining where to go from where you are.
After a break, a new feature of the conference – a panel discussion on valve train dynamics – was convened. And the six experts on the panel – Thomas Griffen and Billy Godbold, Comp Cams; Joe Sherman, Sherman Racing Engines; Dema Elgin, Elgin Cams; John Satterfield, DAM Best Racing; and Mike LeFevers, Carroll Shelby Enterprises, – fielded questions from the audience.
No rest for the weary, Sunday’s activities started with Steve Weinzierl, vice president and chief technical officer of Schrick, Inc, in Osceola, WI, discussing the development of a lightweight, high-speed, diesel engine for unmanned aircraft.
Schrick, Inc., through its division in Remscheld, Germany, supports many different levels of racing ranging from Touring cars, World Rally, Sportscars to Formula One. However, the largest portion of its business is the design of production engines for the automotive industry.
Weinzierl led us through the process of designing an air-cooled, 4-cycle, turbocharged, diesel V-twin. The discussion went from the determination of engine configuration, turbo selection, development of combustion, cooling, and all-attitude lubrication systems, to a one-piece integrated engine mount, oil-cooler, intercooler and intake manifold; all in a package that weighs 53 pounds and develops 46 hp at 6,000 rpm and red lines at 10,000 rpm.
Some of the more interesting things that were incorporated in the design include a 4-second cycle time on the oil. A centrifuge to purge air from the oil. The use of a dyno mounted on gimbles so that it could be operated at any attitude. And, a turbo rotor turning at 270,000 rpm-making 7 bar/36 psi absolute at 16,000 ft.
Next, Lance Ward, of Fuel Air Spark Technology (FAST), talked about airflow determination and the fuel control process in electronic fuel injection. Starting with an overview of the advantages of fuel injection such as: accuracy of fuel delivery, unaffected by G-forces; greater flexibility of intake manifold design; use of higher compression ratios due to more accurate fuel metering; and ease of tuning with a lap top computer; automatic compensation for altitude and temperature; and, of course, the tuning parameters never change once they are programmed.
Ward went on to explain the different ways that electronic injection systems are configured, and how volumetric efficiency determines the engine’s fuel requirements. From there, the ECM derives a base fuel calculation by estimating air flow, looking up the desired A/F ratio, calculating fuel requirements and then determining a base injector pulse width. Finally, the ECM modifies the injector pulse for transient conditions such as cold start/cold run, closed loop correction, acceleration, and battery voltage correction.
After lunch, Joe Sherman of Joe Sherman Racing Engines discussed his winning effort in the 2002 Engine Masters Challenge. The engine was just your basic .040˝ over 350 Chevy, with 6-inch rods, AFR heads, Isky Hydraulic roller cam, Edelbrock super victor intake and Barry Grant 750 carb.
Joe ported the intake ports in the AFR heads, paying a lot of attention to reducing friction, and he spent a lot of time on the dyno sorting out his combination. It was easy to see by the intense interrogation Joe endured afterwards that there was a lot of interest in this year’s winning prize of $100,000 plus contingencies.
The remainder of the afternoon was open for networking while the hotel set up the refreshments for the evening’s "gathering," where everyone was free to corner the person of their choice and find answers to the mysteries of performance engine building. The meeting evolved into small discussion groups centered around one or more individuals in each group.
One such group saw Billy Godbold and Thomas Griffin of Comp Cams, and Dema Elgin of Elgin cams, surrounded by eight to 10 others, all discussing cam topics. Another group was around Joe Mondello, discussing air flow science, and so on around the room. There wasn’t any formal structure, it just evolved that way – networking at its best.
Cliff Apter and his Technical Insights crew were on hand to videotape the conference proceedings. If you are interested in a copy, you can contact him at (303) 745-9735 or e-mail email@example.com. All-in-all, it was one of the best AETCs I’ve been privileged to attend.
A very special mention goes to Joe Mondello and Myron Cottrell, of TPI Specialties. Between them, these gentlemen provided scholarships to the conference for three young men. Kurt Green of Raymond, NE, and Brent Lamb, of Nampa, ID, both graduates of the Mondello Technical School, attended at Joe’s expense, and Jeremy Tobias, Colorado Springs, CO, was covered by Cottrell.