Regular readers may have seen our coverage of the Advanced Engine Technology Conference (AETC) in past years, yet we continue to return for one simple reason: this event stands as the premier arena for top-notch engine builders to compare and share ideas, theories, and research results. No two years are ever the same, and the wide variety of both speakers and subjects has elevated the AETC to one of the "must-do" events on our calendars.
We at PHR think so highly of this gearhead gathering, we decided to co-sponsor the event along with our racy pals at Circle Track magazine. Representatives from other Primedia family titles like Super Chevy, Chevy High Performance, and Stock Car Illustrated also peppered the crowd. There was certainly plenty of magazine fodder for us to feast upon, and this annual conference also serves to inform and entertain the broad audience, which was chock full of professional engine builders and racing luminaries.
Please check out the highlights that follow. We hope you'll gain a bit of insight to what the AETC is all about, and we also expect you'll learn a few things you didn't know before. Naturally, our space is limited and we can only offer a brief synopsis of what each speaker was able to share, but we hope this taste of what the AETC has to offer may encourage you to attend next year's event. You can bet we'll be there again, and if you're interested in expanding your knowledge and having the opportunity to converse with some of the world's most hardcore horsepower fiends, you won't want to miss it either.
You'll also note that one of the speakers was Joe Sherman--the winner of our inaugural Engine Masters Challenge. Joe was invited to speak about his winning entry, and I was fortunate enough to be given a chance to explain the logistics behind the contest for the conference attendees. We're hoping to build the Challenge into an even better contest in the future, and by presenting our plan before some of the best minds on the planet, we may see even more creative entries competing for the big cash. Time will tell, but until then, please enjoy this sample of what the AETC has been delivering to gearheads for the last 13 years, and know we're huge fans of this forum for its wealth of information and ample opportunity for open discussion. Enjoy!
Bob formed Turbonetics (www.turbonetics.com) in 1978, and the company has grown to be one of the authorities on every facet of turbocharging. From housing design to fine-tuning, Bob has seen and done it all. Bob also holds multiple patents and is an active member of both SAE and SEMA. He was named SEMA's "Person of the Year" in 1993.
At the conference, Bob shared a tremendous amount of information regarding turbos, from how turbos are rated to the latest developments in both material and tuning technology. One of the reasons turbos are enjoying such resurgence in popularity is due to advances in modern materials, and the fact that we are now able to see more effectiveness in turbos of all sizes.
Bob made a great presentation explaining how turbos are more efficient superchargers than belt-driven Roots or centrifugal versions, and this is directly related to how they are driven. Engines take in air and fuel, then the energy is expelled through three possible routes: cooling, exhaust, or shaft power transfer. While Roots and centrifugal superchargers tax the shaft power output for their energy, turbos take advantage of the abundant exhaust flow to create boost. This doesn't take shaft power from the engine, and even with the inevitable backpressure "tax" required to spin the turbo, the overall gain-versus-loss still favors the turbo heavily.
Bob was also cool enough to supply every attendee with his internal reference documents. These hadouts contained all of the essential turbo formulas, compressor maps, and reference tables to greatly simplify any research being conducted in this area. If any participant of the AETC was considering turbocharging, these reference aids will prove invaluable.
DAM Machine Shop, Inc.
Like many of us, John Satterfield (www.dambest.com ) has a lifelong obsession for automotive design. He's dedicated a ton of research time toward trying new ideas, calculating the mathematical relationship between various engine components, and just plain finding horsepower. He began drag racing in 1981 and now produces his own line of carburetors for specific applications. We'd never seen solid billet-bodied carbs before, but John's engineering showed how and why his design was superior.
John's speech was enlightening, especially as he walked us through the research and design of his personal engine project. The 321-inch Ford small-block was radically altered to optimize airflow and fuel droplet dispersion, resulting in his target of 800hp in naturally aspirated form approaching 9,500 rpm.
He has a proven method of determining his needs, and further proven methods of achieving them. He explained how it is necessary for the builder to determine a target engine size and horsepower requirement. Once these two variables are solidified, John determines the port area, rpm range (for piston speed), and stroke requirements (for piston position). Next, valve-to-bore distances and valve-to-piston distances are determined, and based on the design of the port in question, John calculates the flow required per crankshaft angle. This is determined to account for design limitations and restrictions, and event timing concerns can be calculated next.
Sounds cool, huh? John also shared his port research, showing how optimum port taper could be determined, and even where the optimal taper should begin, based on the area of the port, the target rpm range, and the overall performance needs of the engine. He also relies on common AutoCad programs to help with corner radii and taper to maintain proper area throughout the length of the port.
John also encouraged us to "think like a fuel droplet" as we modified our intake ports. Builders need to consider the valve clearance relative to the cylinder wall when choosing port shape and contour, and John explained this delicate relationship to us in detail. We were reminded how much influence the piston has in helping or hurting fuel droplet motion, and how these relationships change with rpm, velocity, and the angle at which the port approached the cylinder.
"Droplets hate area changes, and using port molds really helps illustrate this. A directional port likes a long distance to the bore, but not a straight attack. Carbs and droplets hate extra plenum space, and the total volume from the valve to the carb butterflies should be minimized."
John raised plenty of eyebrows when he recommended shorter connecting rods! His extensive research on rod length found more benefit in shorter rods in most situations. This is the polar opposite to the "longer rods are always better" theory most of us have grown up believing.
Naturally, this recommendation is based on research, and hopefully we'll be able to follow up this suggestion with an article detailing the work behind John's suggestion, since we don't have the space to elaborate here.
Managed Programs LLC
Dan is the vice president of engineering and also a partner at Managed Programs LLC, (www.managed-programs.com). They are an engineering and program management consulting firm specializing in the design, engineering, and production of high-end composites for OEM, aftermarket, and racing clients. Located about an hour north of Detroit, MPI works directly with many customers to develop "plastic" parts capable of meeting strict guidelines and parameters, and his AETC presentation would focus on using these new composites for intake manifolds. Dan is also building a '66 Impala SS, so he understands the appeal of both new and old-school technologies.
There are many advantages to running a composite intake, as owners of LS1-urged late-model GM vehicles can attest. There are many more composite intakes out there too, so it's obvious that this is where the future lies. The lightweight, flexibility of design, and positive flow characteristics all contribute to this, and we anticipate seeing even more composite goodies showing up on both the OEM and aftermarket levels in the years to come.
The advantages of composite over traditional aluminum are many, and include the fact that composite has half the mass of aluminum, lower heat conduction properties, a smoother surface, a greater ease of integration (mods are easier to make to the original design), and lower long-term production costs. The composite industry's experience with materials has increased greatly of late, and the manufacturing processes have matured too. The tooling is still very complex in comparison to traditional castings, and the complex geometry of intake manifolds makes for intricate and precise molds for the composite parts. As time passes, these concerns will lessen, and we can look forward to seeing a greater variety of products with incredibly precise engineering at affordable prices.
The use of computer-aided software is paramount to the success of these projects, as parts can be designed, tested, and evaluated almost completely prior to being made. The advantages of this should be readily apparent, and while the costs of this extensive procedure may eclipse traditional aluminum casting, the long-term benefits should be obvious. Knowing that the part will fit and perform prior to making any actual castings, can justify the initial expenses, but the current methods are not ready to give up yet. As more time passes and traditional tooling wears, we anticipate more and more manufacturers seeking out the latest technologies like this to build a foundation for the future. Stay tuned, this is where we're headed.
DR. DEAN HILL
New Mexico State University
Dr. Hill is a professor of mechanical engineering at New Mexico State University (www.nmsu.edu) and was the principal fuel consultant to NHRA for 25 years. He has published many magazine tech articles and SAE papers on fuels, and he consults directly for many race teams. He also builds and races his own drag cars in Stock and Injected Fuel classes. His broad knowledge of fuel chemistry provided the basis for his AETC discussion, and the attendees learned plenty about gasoline, from its chemical structure to its burn rates. There's much to gain from ingesting this vast amount of information, and Dean's easygoing nature helped make a complex subject much more fun to comprehend. Gasoline is, in chemical terms, a paraffin hydrocarbon. The other members of this "family" should be familiar to PHR readers, and you'll soon see a direct relationship amongst many of our favorite fuels.
Depending on the structure of the carbon atoms, different types of fuel are produced. The more carbon atoms there are connected in the molecular chain, the more time it takes for all of these bonds to break during combustion. For example, the fuels with less carbon bonds, like ethane (two carbon atoms), propane (three carbon atoms), butane (four carbon atoms), pentane (five), hexane (six), heptane (seven), and octane (eight) are easy enough to understand and figure out. Hey, we said octane! Now there's a word we know and can relate to. While different octane numbers are assigned to various grades of gasoline, we can now relate to the ratings with a bit more authority. As we add more carbon atoms, fuel burn rates keep slowing down. After the octanes, we move into diesel fuels like nonane and hexadecane, which contain much longer carbon strings and take much longer to burn.
While it may foster flashbacks to the hell of high school chemistry for some, we hope others can better understand what Dr. Hill was trying to do. By educating enthusiasts on the building blocks of gasoline, we'd be better able to understand a most-basic element of what motivates us; liquid gasoline! Dean also answered one of our lingering questions: What is the octane of nitromethane? The answer was as intriguing as the question. While nitro may only have an octane rating of 75 or so, it does not burn. It explodes, and therein lies the key to its mystery. By not burning and rather exploding at a violent rate, nitro sidesteps the smooth combustion issues street enthusiasts wrestle with, and this explains why it performs like it does.
Dean also told us about a lead-based ultra-killer fuel we'd never heard of before: triptane. This represents the best gasoline possible, with a performance octane rating of 150 and the ability to support supercharged engines with 16:1 static compression ratios without detonation. Used as a performance booster to assist fully-loaded WWII American bombers on takeoff, this amazing fuel contains 6 ml of tetra-ethyl lead per-gallon, and cost $5,000 a drum in the '40s. While it's illegal to manufacture now, it was really cool to see how good gasoline could be if refined to its ultimate potential.
Tech Line Coatings, Inc.
Leonard is a pioneer in the coatings business (www.techlinecoatings.com) who has done extensive research on the various types of coating and their broad spectrum of uses as they relate to high performance automotive applications. He's also done his homework on the proper applications of these coatings, and while he no longer provides coating services to individual clients, he's not shy about supplying coating materials to almost all of the various coating services nationwide. The odds are that you're using his products if you've ever coated any engine part. And while he made sure to point out that several companies are not using his products, the overwhelming majority of coating services do rely on Tech Line Coatings (www.techlinecoatings.com).
Leonard began working with coatings in 1967, and has worked on automotive, aerospace, and outer space projects. The further evolution of coatings as a whole, Tech Line Coatings in particular, are changing the way we look at building performance engines. Our own Engine Masters Challenge showed the benefits of temperature management, oil control, and fighting frictional losses through the use of coatings. As these technologies become more widespread, they will also become more affordable. So we'll predict there will be performance coatings in your future!
Leonard's presentation served to familiarize conference participants with the wide spectrum of coating types currently available, and there were a few new types of coating we hadn't seen previously. While we saw the graphite-based anti-friction piston skirt coatings and the oil-shedding silver coatings we've become familiar with, we also saw a new kind of heat dispersant coating. While this may sound like the thermal barrier coating we've recommended in the past, it's quite the polar opposite in that it attracts heat and draws it out of the part or fluid nearby. For example, by coating your oil pan inside and out with this thermal dispersant, your entire oil pan now becomes an oil cooler. By drawing heat away from the oil inside of it, you've made a dramatic difference in your powerplant's ability to shed crucial oil heat, and you've made no modifications beyond applying the coating to accomplish it. That's pretty damn cool!
Leonard suggests we use coatings on pistons, headers, bearings, valves, combustion chambers, camshafts, gears, radiators, brakes, wheels, intake manifolds, and much more. Sure, he sells coatings so we expect a generous list, but we were also able to hear his reasoning and research behind these suggestions and were impressed with the benefits. Considering the great care and expense we go through in creating custom engines to fit specific needs, the added expense of coatings seems like a minor cost when the long-term benefits are considered. More power can be found, more durability can be gained, and greater thermal control can added to both. The time for coatings is here, and you'll be hearing and seeing much more about them on these very pages.
COMP Cams, Inc.
We've worked with Billy on several projects and stories you've already seen, and more you'll be reading in the future. Billy is the man behind the development of new camshaft profiles and designs at COMP (www.compcams.com), and the results of his efforts have won many races. His usual focus is on race-only engines, but the benefits of his research, and those of his dedicated teammates (like Thomas Griffin, whose work has also been explored on our pages), is apparent in many new COMP street profiles. It's this level of dedication on all fronts that makes Billy one of our favorite guys, and his lighthearted comedic nature is always appreciated, too. Don't let his degrees in both physics and nuclear physics fool ya- Billy's a down-to-earth guy who designs camshaft profiles based on science and experience, and his presentation walked us through the kinds of things he does for COMP on a daily basis.
Billy's AETC presentation was focused on optimizing valve events to improve performance. By looking directly at each small portion of a valve event, and designing the portions to work perfectly in concert with each other and the wealth of components around them (not the least of which includes the valve spring), the optimum efficiency and power can be realized for the application.
Beyond lift and duration, there are many other dimensions directly relative to camshaft and valvetrain performance that we don't discuss as often. Billy defined these terms for us and walked us through their specific functions relative to the total valve event. He clearly defined the velocity of the lobe, the acceleration relative to the velocity, the rate of change in the acceleration (called "jerk"), and more. You can see how these measurements could be easily overlooked, but Billy's research into each portion of the total valve event has allowed him to fine-tune these most interesting dimensions.
Once we'd been introduced to these terms and measurements, we once again looked over the entire valve event series, and began to learn to look at cam lobes the way Billy does. For example, we looked over a graph of a typical BGN exhaust lobe. By explaining every portion of the graphed lobe, we could easily see how moving the exhaust opening point later in the cycle would increase the lower rpm torque by effectively lengthening the power stroke. Interestingly, if we opened the exhaust valve earlier, we'd also see a benefit in gaining more time to remove the exhaust and potentially picking up some efficiency there. So, which is better, and how should we plan out the exhaust event to benefit us the most? It ctually depends on many other factors, but it proved the point Billy was trying to make. With so many variables and possibilities in each cam lobe, and even in the overlap relationship between them, you must research the need honestly and completely before you can determine the best-possible lobes for your application. The more we learn about camshaft motions, the more we know about engines.
Software and systems engineer Lance Ward has much time and effort invested into the latest electronic fuel injection systems offered by FAST (www.fuelairspark.com), and he was able to share some of the newest innovations being offered on their broad-based systems with the conference attendees. While we're big fans of current systems, the future is even brighter for fans of EFI or current owners of FAST components.
Lance began his discussion with a quick rundown of EFI basics, followed up by intricate discussion of mass airflow sensors and rates. Ward also offered comparisons between different types of systems and pointed out the advantages and drawbacks of several varying designs. We were able to review various tables and learn how speed density is determined. Many different factors are involved, and by working toward clearly defining each of these signals more clearly, FAST is helping make their systems more responsive and flexible to the needs of the engines they feed.
Also, we were treated to an in-depth discussion on one of the most important factors of performance engines: volumetric efficiency. We know how increasing powerplant efficiency, we can gain more horsepower and torque by more effectively converting fuel and air into torque, but other benefits are not so apparent. Gains in fuel economy, throttle response, and average power output are also realized. Volumetric efficiency (VE) is directly related to torque, and increases in VE generally result in a torque gain. VE will be greatest at peak torque, and lowest at idle speeds. Normal engines are about 80 percent efficient, while a well-designed performance engine can reach a full 100 percent at torque peak. Supercharged engines can actually operate at beyond 100 percent efficiency, since the measurement is based on the engine's air capacity. Since superchargers force more air through the engine than it can normally ingest, the volumetric efficiency measurement can surpass 100 percent.
Another critical factor is how the EFI system calculates fuel needs. By estimating the mass air flow at a given moment and determining the desired air/fuel ratio (normally based on oxygen sensor feedback from the exhaust), the computer can develop a very good idea of the current fuel needs of the engine. It will respond by opening the injectors for the correct amount of time, and the constant feedback from the oxygen sensor will result in constant fuel metering and accurate delivery from each injector.
We also learned about injector opening offsets; better defined as the operational delay between the moment the engine control unit sends the electrical signal to the injector and the actual opening of the injector. This time varies based on many different factors (including injector design type and size), and Ward's clear explanation of the issue and his solutions based on in-house research were enlightening.
Different setups require different details to be attended to, and seeing the broad spectrum of efforts FAST is investing toward making EFI even more effective were welcomed. We know there is still a disparity among carburetor and EFI fans, but as EFI continues to evolve, any questions regarding which system is best for the avid street enthusiast will be answered. The proof is in the results, and while carbs will always be a good, affordable, and viable way to feed fuel to your engine, EFI just keeps getting more and more accurate.
Joe Sherman Racing Engines
Readers of PHR will recognize Sherman as the winner of our inaugural Engine Masters Challenge (www.enginemasters.com), and this distinction got him an invitation to speak to the AETC crowd. He answered a battery of questions from the participants regarding his engine design process, and enlightened many with his responses.
When asked which engine modeling software he used to develop his Challenge-winning combination, he answered "What is that?" While Joe knows this software exists, he relies on the wealth of experience that he's gained in order to design performance engines to suit specific needs. We know our readers can appreciate this hands-on approach as much as the engineers in the audience did.
Joe's strategy to develop a serious combination on a "mule" short-block, then transfer all of his top-end goodies on to a fresh bottom end just prior to competition, met with much crowd approval. Obviously, many other participants worked their Challenge engines over pretty hard before we saw them, and Sherman's relatively fresh bottom end had to be worth a few ponies.
He also commented on his feelings toward coatings, fine-tuning, and how the final ignition timing corrections were the last thing he changed prior to the competition. By creeping up on the desired combination and saving his best stuff for the actual competition, Joe was able to take a solid and proven combination to the top without any real trickery. That in itself is worthy of respect, and Joe's talk with his peers regarding his many decisions was a credit to Joe himself and the Engine Masters Challenge.
The Challenge dares the best builders to bring their best work, and provides the level playing field required to put up or shut up. We're proud to have Joe represent the Challenge as its first champion, and his ideas, techniques, and strategies will certainly impact the competition for many years.