Attendees were also given a first look at an LS-based Sprint Car motor that will be aimed
Dorton replaced the rod, but he said that if the ding had been found before the rod had been installed in the engine, it could have been fixed by gently grinding the sharp edges away in the same direction as the forging's grain and the rod could have been saved.
Individual Cylinder Tuning
One topic that was touched on by a handful of presenters was individual cylinder tuning. This is most often done by doing combustion pressure analysis on individual cylinders. The idea is simple-more pressure equals more power-and by tuning the air/fuel mixture to the cylinder as well as the timing of the spark, you can maximize the power each cylinder produces.
Unfortunately, there are a couple of problems with this scenario. The first is that the equipment to accurately perform combustion pressure analysis on individual cylinders of a running engine (and remember, it has to be running at race speed on the dyno since nobody cares about maximizing power at idle) is prohibitively expensive. Currently, this equipment is within the budget of only a handful of the top NASCAR Sprint Cup engine builders, Universities such as Clemson which participated in the conference, and the OEMs. But hopefully, prices will drop in the future to a level that the rest of us can afford.
Here's a shot of the completed spec Sprint motor.
Doug Yates of Roush Yates Engines, spoke about using a combustion pressure analysis system to aid the development of his Dirt Late Model engine program, and brought up several interesting points. The biggest is that he says it's actually impossible to balance every cylinder in most race engines so that they make the same amount of power. This is because of the common plenum design that's an
integral part of a single-plane intake manifold.
The common plenum allows different cylinders to rob more fuel and air from the manifold depending on the firing order. The best plan, he says, is to try to maximize the power of each cylinder depending on its situation rather than find the cylinder that produces the most power and try to bring the other seven up to that level.
Ring Seal Isn't Always about the End Gap
Matt Hartford of Total Seal Piston Rings gave a very informative presentation on the technology behind performance piston rings. Interestingly, he stressed the point that good ring seal goes way beyond simply filing your rings for the correct end gap. Properly separating the combustion pressure from the crankcase also requires the rings to properly seal between the ring and the cylinder wall, as well as between the ring and the ring lands cut into the pistons. And when you combine this with the fact that most engine builders require the ring package to offer as little friction as possible, it can become a very tricky task.
JE Pistons' Stephen Golya shared some very interesting research showing the stressed areas
That's why many modern advancements, such as diamond lapping, high quality materials, and coatings have offered incredible advancements in ring performance. Of course, no matter how much you spend on your rings, they also depend-as always-on pistons with flat and true ring lands and a proper hone job in the cylinder bores.
Pistons May Have a Very Interesting Future
JE Pistons' Stephen Golya gave attendees a glimpse into the future of racing piston development. There was a lot of heavy tech info provided but the piece that caught our attention is the research being done to minimize friction between the piston and the cylinder bore. Traditionally, most manufacturers have attempted to cut friction here by reducing the size of the piston skirts. That's gotten us to pistons that can get by with surprisingly small slipper skirts, but in the future, manufacturers may follow a different track.