The stock 2.4-liter Ecotec...
The stock 2.4-liter Ecotec engine is the standard powerplant in the Chevy Malibu and HHR.
That other way was an electronic fuel injection unit. Iaia did take a look and he liked what he saw. "It instantly became evident to me that, based on what my goals were for the motor, I could make more power with greater reliability, more features, and for far less money by going with the modern technology than I could with this relatively ancient technology that everybody keeps pushing in Midgets and Sprint Cars."
And with that the die was cast.
Iaia started by designing his own cast aluminum intake manifold, stainless steel velocity stacks, all of the hardware, fuel rail, injectors, sensors, and fuel regulator under the banner of his aptly named company Revolution Racing Engines.
The ultimate goal is to employ new technology to lower the cost and increase reliability of a racing engine while providing more features for the buck to the typical Saturday night racer who has a family to feed or a business to run. But that was easier said than done.
There were many challenges in building the engine, everything from funding to the fact that it was Iaia's first experience building an electronic motor. But one of the biggest had to be getting fuel to the motor.
The stock engine's lubrication...
The stock engine's lubrication system received an extensive overhaul courtesy of Iaia. This oil remote assembly allows plumbing of both an oil cooler and an oil accumulator. Keith Iaia
"Most EFI engines operate off of an electronic fuel pump since they want to see a steady fuel pressure at the fuel rail for the nozzles to fire correctly. Being an old school Midget guy and a safety conscious Midget guy, I was naturally opposed to an electric fuel pump. I've seen bad things happen when things go wrong in one of these cars. The idea that there could be a crash or mishap where the fuel line could be breached and the fuel pump could be left on, pumping fuel out to the atmosphere was something I wasn't comfortable with."
Although there have been a lot of advancements in the relays that control electric fuel pumps, Iaia opted to stick with a mechanical one for now, leaving the door open to move to electric in the future. "When the motor is not turning, the pump is not turning, and I like that," he says.
An individual-runner intake,...
An individual-runner intake, engine adaptor, and oval-track oil pan (pictured) are among the specially designed cast-aluminum parts produced by RRE for the project.
Using a mechanical fuel pump on an electronic engine in itself was a challenge. A mechanical fuel pump is linear in nature, wherein the more the engine turns, the more fuel the pump moves to the injectors. The problem is that electronically controlled injectors don't like that-they demand a steady and consistent flow. Iaia, the engineers at GM, and Dan Korrect at KRC got real creative with the fuel regulators to stabilize the fuel pressure at the rails as much as possible.
In the world of EFI, a fuel-pressure regulator is an adjustable diaphragm-style regulator. As an example, if you set it at 60 pounds it allows full flow of fuel through it all the way up to 60 pounds, anything beyond 60 pounds it begins to bypass.
"Our initial efforts involved simply employing one regulator of that type back to the vacuum side of the manifold. That's when we found a problem. When we set the regulator at 60 psi, when the engine hit 3,000 rpm, it worked fine. But at 7,000 rpm the regulator wasn't capable of bypassing all the fuel that the pump was putting out, so the pressures at the rails went up anyway," explained Iaia.
Their solution to the problem was to put that regulator on the fuel-rail circuit and then add a Kinsler-style poppet mechanical bypass on the bypass circuit and set it at 60 pounds. Theoretically what would happen is at idle or low rpm the poppet-style bypass would be shut because it wouldn't see 60 pounds and all the fuel would be flowing through the fuel-rail circuit. That regulator would maintain 60 pounds, or as close to 60 pounds as possible, at idle speed.