Every year many of the nation's best and most successful engine builders gather for the annual Advanced Engineering Technology Conference (AETC) held just before the start of the PRI racing tradeshow. The conference brings in a different set of speakers every year to share some of the latest advancements in engine technology. Many of the engine builders we've spoken to have told us that they have been able to take some of the things they've learned here and applied it to their own programs for additional wins and faster lap times.
At Circle Track we're always looking for the best ways to provide you with the very best engine information—whether it comes from the renowned engine builders in the industry, parts manufacturers or conferences like this one. That's why for several years Circle Track has stepped up as a corporate sponsor for the AETC conference. It's not only our way of giving back to the community with a chance to gather and discuss ways to improve racing, but it also allows us the opportunity to share with our readers some of the more helpful things we learn. And you'd better believe we learn something new every year.
We understand that many of the readers of Circle Track are racers who will purchase their racing engine from a professional builder. But there are benefits found at AETC to anyone involved in racing. Lots of the information we're passing along will help you with the performance and longevity of your engine, everything from choosing the right motor oil to data acquisition during track testing, while other nuggets of information can help you determine if the engine builder you are depending on is up on his game and capable of building you a race engine that is up to date with the very best in performance technology.
Driven Racing Oil’s Scott Diehl demonstrates the benefit of a quality synthetic based moto
If we are honest with ourselves, as racers we don't care what's in the oil as long as it helps make power and meets our expectations for protecting the engine's moving components. When you get right down to it, whether it is made from some miracle synthetic material created in a lab or dishwater from the local diner doesn't matter to most racers as long as you get good engine protection with minimum horsepower drain.
So the question becomes, what oil works best for my race engine? Scott Diehl of Driven Racing Oil presented some of the latest findings in the development of performance motor oils. Finding the best oil for your race engine is always a balancing act. To provide maximum protection for your expensive engine components the oil must be able to maintain a boundary layer of fluid between two moving components. As the temperatures and engine speed get higher with a performance engine, this usually means increasing the viscosity.
But, thicker, more viscous oil is harder to pump through the engine, robbing you of valuable horsepower. Diehl informed the conference attendees of a new synthetic molecule that Driven Racing Oil is starting to use in its formulations that creates an oil base stock that's more resistant to heat. The new base stock is called Metallocene Poly Alpha Olefin (mPAO for short) and it is an improvement on what was previously considered the best synthetic base oil stock for performance racing—PAO.
Diehl says that currently, Driven Racing Oil is the only company producing racing oil using mPAO, and we're interested to see when and which other oil companies follow suit.
However, even with the improved synthetic oil technology, you still have to carefully balance oil viscosity with other factors including engine rpm, bearing clearances and the oil temperature you see on the racetrack. Many racers and engine builders are fearful of pushing the limits using a thin oil because they simply can't afford to push beyond those limits and damage an expensive engine. There is, however, an option besides simply using ever thinner oil until you start damaging bearings. A Stribeck Curve is an equation used by lubrication scientists that basically tracks an oil's ability to protect given engine speed and loading. Driven's tech department is actually able to use the Stribeck Curve to help its customers determine exactly the viscosity that will provide the best combination of good engine protection without absorbing excessive horsepower. If you can provide the engine horsepower, the rpm range the car sees on the racetrack and the typical oil temps, Driven can provide you the correct viscosity and grade of oil and even what your ideal bearing clearances should be.
Ron Sledge of King Engine Bearings
Whenever racers or engine builders tear down an engine for a rebuild and see damage to the main or rod bearings, one of the first assumptions is that the bearing clearance wasn't sufficient. Obviously, if you've got a main or rod journal rubbing a bearing, the fix is to add more room for the oil to cushion between the two components, right? Not necessarily.
Ron Sledge of King Engine Bearings reminded attendees that tightening bearing clearances can often help the oil do its job better. Tighter bearing clearance can actually reduce the peak bearing loads because the smaller space the oil had to fill makes the oil film act stronger. The result is better distribution of the loading over a larger area. Now the oil is better able to hold the journal away from the bearing because the loading is distributed better.
Tighter bearing clearances can also be the solution if you are noticing bearing pitting. Pitting normally happens when you have aeration, or small bubbles of air, of the oil. When the oil is under pressure the air bubbles are compressed, and when that pressure is reduced the bubbles expand. In a race engine with a high rpm range any area where the pressure is reduced can allow any bubbles that are in the oil to practically explode, severely reducing your oil's ability to protect the bearing. This is how pitting often forms on the bearing babbit. Tightening the bearing clearance helps hold the oil pressure higher in that area, keeping any aeration in check until the oil exits the bearing.
This isn't a hard and fast rule because it certainly is possible to have your bearing clearances too tight, but it definitely is a point to consider if you are puzzling over the cause of bearing damage found.
NASCAR teams regularly spend millions of dollars on their engine R&D programs, and regular
New Camshaft Tech
One of the biggest advancements in camshaft development for the last several years is Comp Cams' new Four Pattern camshafts. You likely saw the Quick Tech on these cams in last month's issue of Circle Track but Comp's Billy Godbold provided the lowdown on these cams for the gathered engine builders. Multi-pattern cams are nothing new in the racing industry, but by utilizing CNC technology, Comp has finally found a way to make them affordable for the Saturday night racer.
Using much of the R&D they had invested into Cup racing engines (they are no longer used thanks to fuel injection) Comp has been able to develop four-pattern cams that produce approximately 1 to 2 percent more power throughout the rpm range on engines with a common plenum. This is done by using the cam to compensate for the differences created by the long and short runner splits to create a more consistent air/fuel balance from cylinder to cylinder. Besides the increase in power, Godbold says the new cams can also create a better response at low rpm without the typical fall-off in the upper rpm range. They are also less sensitive to weather changes. Right now all the new four-pattern cams are for use with hydraulic lifters, but we expect to see more race oriented solid lifter cams soon.
Federal Mogul showed some photos from its R&D tests with a new polymer bearing material (t
The Future of Engine Bearings
The future is here for engine bearings. Two developments in the automotive industry will likely be shaking up the bearings you see on parts store shelves pretty soon.
During the presentation of Federal Mogul's Bob Sturk, the engineer revealed that Europe will be requiring all new cars to be easily recycled. This means that the lead that has been used in engine bearings for decades will no longer be allowed. Right now, this is a Europe-only rule, but it will also affect domestic automakers because if they hope to export their cars to Europe they must conform to the rules as well. Meanwhile pressure to improve fuel economy will be leading to more and more hybrid vehicles running combustion engine equipped with start/stop technology. Start/stop is the buzzword for an engine that shuts down on its own when not needed (like sitting at a stop light) and restarts on its own with the help of the hybrid's electric motor when you step back on the accelerator. This technology can help save gas, but it is also very hard on the engine bearings. Every time the engine stops spinning, the oil loses its hydrodynamic wedge and the crank and rods can settle against the bearings. Then, when the engine is restarted you can have metal to metal contact.
Combined, this means bearing manufacturers like Federal Mogul must create a new line of bearings that use no lead but are tougher than ever to handle 100,000 miles or more in a start/stop engine. As a result, Federal Mogul has been experimenting with many different polymers to replace the lead layer in conventional tri-metal bearings, and Sturk says the company's new IROX coating shows great promise. Currently, no one in the U.S. is planning to take away the conventional tri-metal bearings that engine builders have depended on for decades, but Federal Mogul is able to come up with a more dependable bearing material that's more resistant to heat and even short-term drops in oil pressure that could be a benefit for the racing industry as well.
Racepak’s Donny Cummins
The True Cost of Racing
Stock car racers are quite advanced when it comes to technology in many areas. Highly advanced shock packages and ultra-light engine components come to mind. But because of a ban on almost all kinds of electronics during a race, one area where the Saturday night stock car racer seems to be behind versus other forms of motorsports is data logging.
Granted, quality data logging equipment can be expensive, and many of us feel we can get all the info we need during a track test via old-school methods. But one point Racepak's Donny Cummins made during his excellent presentation is that we as racers need to understand the true cost of our activities.
For example, Racepak did some research into the costs incurred by a typical Late Model race team running on asphalt. Racepak assumed the team would run twenty 100-lap races over the course of a season and a fresh rebuild on their racing engine would be six grand. Here's the breakdown at the bottom of this column below Cummins picture.
Add it all up and you get 8 bucks every time the race car crosses the start finish line, and that's not even including the cost of wreck repair or replacing worn parts! Now consider the fact that your race car doesn't know the difference between a race and a test session and you realize that the costs are every bit as high when testing. Suddenly, spending some bucks on data logging equipment so that you are able to collect more data and learn what you need in few test laps starts to look like a very economical decision.
||$3.00 per lap ($6,000 total cost)
||$2.00 per lap ($400 per set)
||$1.00 per lap ($8.00 per gallon)
|Non Car Expenses
||$2.00 per lap (travel costs, hauler fuel, food, etc.)
Mahle is experimenting with using its famous Grafal anti-friction coating as a way to funn
New Bore Materials
Years ago, piston manufacturer Mahle was one of the first performance companies to integrate a low friction skirt coating into many of its racing piston designs. At the AETC Mahle revealed that it is continuing to look for out-of-the-box innovations that will help racers and engine builders. One idea Mahle's Brad Green presented is to use a cylinder bore liner with a high silicone content. By using a special machining process with certain chemicals, parts of the other components in the bore liner are removed, revealing the large silicone "nodules" at the surface. The idea is that the silicone creates less friction as the piston travels up and down the cylinder bore.
Green also showed a photo of a piston with a very unique coating on the piston skirt. The coating itself was Mahle's standard Grafal coating we've seen for a few seasons now, but how the coating was applied was quite unique. Green explained that the Grafal is "printed" onto the piston. This means that Mahle can change the shape of the printed area relatively easily. The company is looking into printing the anti-friction coating into a sort of chevron pattern to funnel more oil to areas of the piston skirt that sees more loading against the cylinder bore. It's a simple way to make the coating perform an extra job without adding any real cost to the manufacture of the piston.
Check out how Mahle’s racing pistons have advanced over the years. By concentrating materi
Currently, we don't know when or if these ideas will ever make it into production. But we're glad to see companies like Mahle continue to seek innovation to help us make more power with greater longevity.
Clemson University’s Dr Robert Prucka with one of his advanced computer simulations in the
Making Horsepower in the Computer
Clemson University's graduate program for automotive engineering is called CU-ICAR, and they've presented at the AETC for a few years now. One of CU-ICAR's specialties is developing simulation programs.
Presenters Dr Robert Prucka and Justin Callies revealed just how far we've come in our abilities to simulate exactly what is going on inside the engine. Don't make the mistake of thinking that sitting down in front of a computer to work on your engine is the realm of eggheads in lab coats. Simulations are already the area where the greatest advancements in creating horsepower are being made—and it's only going to become more important in the future.
Consider all the options you have to make as a racer. For example, how confident are you that your headers are the best choice possible for making the most power where you need it on your racetrack. The options available for engine headers are tremendous. You can change tube diameter, tube length, collector size, steps, the number of steps and even the distance between steps. And the best option can change depending on the rpms, cubic inches, and even elevation. So the best header for the guy racing in Florida on a tight 3/8-mile track may not be the best header for the guy racing the very same engine in Colorado on a half mile. Now imagine how much time, money and aggravation you can save testing any number of header configurations on a simulation that takes your engine configuration into account right down to whether you are running an open spacer or tapered. Obviously, such simulations are readily available to the common racer yet, but we can tell you it's only a matter of time. The 2012 AETC had a lot of valuable information and with PRI's move to Indianapolis in 2013, it should only get better.