Today marked the opening day for the 22nd annual Advanced Engineering Technology Conference (AETC) that takes place in Orlando, Florida the week of the PRI Trade Show. After 22 years the annual event might still be the best kept secret within the performance industry. Around 100 individuals from across the nation filed in today for a chance at hearing from some of the most highly respected technical experts within engine technology.
This year’s theme is the latest advancements and developments in engine performance technology. Day one started out with a returning speaker Dr. Robert Prucka, an assistant Professor in the Department of Mechanical Engineering at Clemson University.
Dr. Prucka spoke on the use of simulation and experimental results to improve engine performance. Dr. Prucka, who admitted more than once that his goal was to one day press a button and design a complete engine using software, would explain the motivation for engine simulations.
“The experimental data acquisition software at Clemson costs us over $190,000.” Explained Prucka. The benefits of having a much more affordable simulation software would allow you to identify problem areas that are difficult or expensive to measure experimentally, and not to mention the savings of not having to create prototype after prototype to test.
Which is all great in theory, but how close are we to having this type of software? Some simulation software actually does exist. Prucka went on to explain the four types of simulation software.
- 3-D CFD
- 1-D CFD
- Mixed Experiment with 1-D CFD
My goal is to one day press a button and design and test a complete engine
So how close are we though to accomplishing his goal? Prucka doesn’t think it is that far off, “I believe we are within ten years of designing a complete engine through simulation software. Maybe not at your desktop, because of computing power, but it will happen very soon.”
Up next would be Richard Keller of Champion Spark Plugs. Keller has been with Champion for over 30 years since he graduated from Purdue in 1980. This man has been extremely influential in the developments of the plugs we use today. Richard oversaw Champion’s popular Platinum Power, Double-Platinum, and Iridium spark plugs. So when Keller took to the stand to speak on ignition principals for peak engine performance, it was safe to say he had everybody’s attention.
With such a broad topic he made it very clear from the beginning just how unique motorsports and performance ignition systems are. “When compared to the automotive, industrial, and small engine systems. The Motorsports ignition system is a very unique environment,” Explained Keller. “But the thing to remember is spark plugs are only a part of the system, the whole system needs to be considered.”
One overlooked aspect of the ignition system is the fuel mixture. “Different fuels present different challenges. Knowing your fuel is a big part of the battle,” Keller said. He went on to explain how the most ignitable mixture may or may not be the best mixture for peak power. Ignitablity was defined by Keller as a relationship between how easy the mixture is to ignite, and how effective is the ignition system is in igniting the mixture. “You have an ignition guy telling you to worry about your fuel, that should tell you something,” Keller warned.
- Fuel/chamber conditions that allow for the fuel to auto ignite in a region of the end gas in an area other than where the intended flame has already been initiated by the spark plug.
- Thermal runaway of one or more components within the combustion chamber, where ignition is initiated based on the heat of the part and occurs before the intended spark occurrence.
So the question becomes, what can you do to prevent or fight these two? Keller offered a few tips, review your fuel specs. to ensure that the Motor’s Octane Number (MON) matches the chamber compression, reduce cylinder head temperature, add more mixture turbulence, and enriching the fuel settings can help cool the mixture.
Keller also offered 4 common misconceptions when it comes to ignition systems.
- A mega-voltage system is required – the chamber conditions, not the ignition system, dictate the voltage requirement.
- Peak voltage defines how the system will perform – Rise time and arc duration are at least as important. In a performance setup, they are most important.
- RPM is not an important factor – In most cases, the RPM will dictate whether the ignition system is even appropriate. Inductive systems typically suffer at high RPM.
- If the coil is a high energy design, the rest of the setup should work. – The energy from the coil still needs to make it to the end of the spark plug to do the job. Voltage needs to be contained and applied at the right moment.
The further you go for performance, the higher the load is on the spring and the shorter the life is of the spring – Jason Youd
Jason spoke on valve spring science, selection, and optimization for best performance and longevity. “The further you go for performance, the higher the load is on the spring and the shorter the life is of the spring.” Jason explained. “Oiling is also a large factor in determining spring life.”
Jason would show the effect that temperature has on valve springs life, and how crucial it is to perform all of your testing at temperature. As the temperature rises the open load and spring rate reduces at a great amount, at 350 degrees the spring open load reduces by 90 pounds. “That’s 90 pounds you’re taking out of the system at 350 degrees, even at 150 or 200 degrees you’re still loosing 25-30 lbs. This is why it’s so important to run any robust testing at temperature.” Explained Youd.
After each speaker the people in attendance have an opportunity to ask questions they might have to the professional. During this time Jason fielded a question about coil-binding valve springs that caught our attention. The often debated question was, “how close should valve springs come to coil-binding.”
Jason, while laughing responded, “Well I usually joke with people and tell them 75 thousandths away from coil-bind plus or minus 25.” Obviously a very broad range, but it got quite the laugh from the crowd. “While that’s a generic response, the truth is it can be very dependent on your application,” Youd explained.
Jason closed out the session by answering a question about what advancements are we likely to see in the coming years. “Materials, and processing. There’s a lot of new materials. There’s a domestic supplier that is coming online. Soon you will pick from 30 alloys instead of 4.”
Bill Hancock has been involved in almost every type of racing out there. Bill has worked for the Chrylser Corporation during the 1970’s NASCAR program, he has worked side by side with some of the greats in not just NASCAR but in almost every form of motorsports. This great has spent plenty of time not only at the track but also in the shop getting his hands dirty.
The A-B-A Method Of Testing
Hancock went on to explain a method that he used anytime he would test anything on a racecar. He called it the A-B-A method of testing.
- Make three runs that are close and average them – This is your “A”#
- Change parts and make three more runs – Average these runs to get your “B” number
- Change parts back to the “A” configuration and average three more runs
“IF and only if you can repeat your original “A” number then you can compare the results and make a decision on which is better,” Said Hancock. He explained that there are so many variables that are hard to account for like weather conditions, and track conditions, that the A-B-A method is a great way to know if something truly made a big difference or if some other factor outside of the teams controls led to the improvement in time.
It was evident right off the bat just how serious he took testing, and he offered suggestions that even engine builders could test by, not just race teams. “We always had a plan when we arrived at the track,” explained Hancock. He went on to explain that while testing is great, there are reasons not to test. One reason you would not want to test would be the lack of recovery time.
“One year during a Daytona test we lost 7 motors! And let me tell you, you haven’t lived until Maurice Petty has grabbed you by the neck and said what what do we do now?” While it got a laugh out of the crowd, the point was evident. If you do not have ample time to fix what could happen during a test, it may not be the best time to try something radical during a test session.
The overall theme throughout his message was never change more than one thing at a time. “Let’s say you want to try a new cam, but to try that cam you need to change valve springs. We call that a system change, you are technically not changing just one thing at a time, but instead you are testing that cam and spring combo versus the other combination.”
He closed with this thought when speaking of whether or not a test was successful if you came home slower than when you arrived, “Worst case scenario, you come home after trying ten things and are slower than when you left… Was it a successful test? Hell yes! Now you have 10 things that you know not to try on race day.
Make sure you check back tomorrow for our day two coverage from the AETC.