Knoxville, Iowa (March 19, 2010) Knoxville Raceway, in an attempt to make racing more affordable for its 410 c. i. racing division, has legalized new displacement criteria for engines. Known as the "Knoxville Open Sprint Engine", this Knoxville, Iowa track will allow 435 c. i. engines with a maximum displacement of 440 c. i. Certain restrictions will also apply.
These changes will allow several other configurations in the works by engine builders and manufactures to try to come up with engines capable of running a complete season on one rebuild and costing a lot less for the initial investment.
According to Knoxville Competition Director John McCoy, "We absolutely do not feel this is creating a 'new class', it is simply opening up some of the current restrictions that make it too expensive to operate a competitive sprint car at Knoxville. It is all about cost per cubic inch and right now it is unsustainable to our headline division"
Knoxville Raceway has decided to take a stand and go back to the roots of sprint car racing at Knoxville where for many years there were no limits on the engines and many were built by the competitors themselves with help from the local machine shop. With a few rule changes we believe this is once again possible."
McCoy cited the high number of older 410 engines which are "out there" but cannot compete with the newer heads and assemblies currently used. Most of these engines have an older style head and injector combination that (at best) might produce 800 actual horse power. Engines built today are producing over 900 horsepower.
"Engine builders from across the country are unable to agree to anything to restrict the current engines. By raising the cubic inches from 410 to 435, teams may gain 50-70 horsepower, just enough to close down some of the gap with the high dollar pieces out there today," said Director of Racing at Knoxville, Ralph Capitani. "It's also important to acknowledge," he continued, "that some may want to build a new engine with these specifications. We certainly will allow this. It's important to understand that we cannot open up the cubic inches without some restrictions. That would solve nothing and probably make the cars just too fast, especially at Knoxville."
With these restrictions, the engines will not yet put out the horsepower delivered by the professionally built engines running up front today. They will be an excellent choice for beginners and great for back up engines. These restrictions will not affect anything that is running today. All of the engine rules that are in place will stay the same. This is an option at Knoxville.
"We are confident that with the right team and driver these engines will perform very well at Knoxville," McCoy said. "We expect this particular engine will also be a great stepping stone for the 360 teams that want to move up to the premier sprint division. We also hope other areas in the country will watch this development and allow these engines to help with their car counts."
Specifications for the "Knoxville Open Sprint Engine":
Maximum Bore 4.165 (4.00" stroke = 435");
Maximum displacement 440 cu. in.;
Maximum intake stack I.D. 2 5/8" for minimum 4";
Maximum header size 1 7/8";
Minimum 15 degree valve angle. This allows -12 (Brodix model #) 15 degree heads /16, 18 and 23 degree heads. This will make the GM crate 427 engine legal
Capitani and McCoy both express that anyone wishing to build a “Knoxville Open Sprint Engine” to please contact the track office so that there are no misunderstandings.
- Knoxville Raceway on Mar 19, 2010
- Article Date: 3/19/2010