The United States Auto Club (USAC) is now delivering sealed Honda K24 engines to competitors for use in the Honda HPD Midget Series, which also runs similarly powered Ford Focus engines. The new option will make it easier for racers to keep their vehicles tuned, and the engine’s lifecycle should help reduce overall costs.

Changes to the K24 crate engine include new oiling and intake systems.

The Honda/USAC partnership was announced last year, followed by Honda Performance Development (HPD) engineers working with USAC to finalize the setup. Although fewer than 10 engines are currently in competition, the initial reaction and enthusiasm are positive.

“We are pleased with the product and certainly as a corporation pleased to be part of USAC’s midget ladder,” says Marc Sours, HPD senior manager and chief engineer.

“We worked hard to get a good engine right off the bat,” concurs Eric Rankine, director of competition for the HPD series. “We introduced it early to mid-season, so most racers already had their engines ready to go. There’s interest and we’re getting calls.”

How much power?

Basically, Honda ships the 2.4-liter crate engines with an 11.0:1 compression ratio to USAC for preparation and sealing before they’re sold to competitors. This is the same engine found in the Honda Civic Si coupe and rated at 205 SAE horsepower at 7,000 rpm with 174 lb-ft peak torque at 4,400 rpm. Ford used to be the series sponsor, and its 2.0-liter engine has been raced unchanged for a number of years. It’s built with mechanical fuel injection and wet-sump oiling while the larger Honda engine is approved with EFI and dry-sump lubrication.

The Honda K24 mounted in a typical Midget racer.

“Currently, the Honda engine on ethanol unrestricted in current configuration makes 232 horsepower,” says Rankine. “We use a restrictor plate to get the engine down to approximately 170 horsepower to be on the same playing field as the Ford.”

The engine is mounted at a 30-degree angle for better weight distribution. Note the combined oil pump, power-steering pump and alternator. Also, the exhaust is integrated into the cylinder head.

The restrictor plate is mounted between the throttle body and a custom intake manifold produced by Drinan Racing Products that also supports the MAP and air temperature sensors. It bolts to the factory intake base where the fuel injectors and fuel rail are mounted. The fuel delivery and spark are controlled by a factory Honda ECU. While the Ford engine uses a mechanical fuel pump, the Honda-powered cars will utilize electric pumps and fuel regulator mounted in the fuel cell. A single -6 AN line brings the ethanol to the injectors.

“We had HPD work on the fuel mapping to get the air-fuel correct with the ethanol,” says Rankine, adding that VP Racing supplies the spec C85 fuel. “Also, they helped with cooling and longevity of the engine.”

Improved cooling needed

The Honda cars do require a larger radiator to chill down the K24.

“I don’t see any reason why these engines can’t go five to eight, even 10 years before they need refreshening,” praises Rankine. “That’s based on the history we’ve had with the Ford motor. As long as you change the oil and don’t get them hot, you’re good.”

The Ford 2.0-liter Midget engines have mechanical fuel injection and wet-sump oiling.

The Honda engine is also converted to dry-sump oiling with a Barnes 3-stage pump and an 8-quart reservoir. In a unique, space-saving move, USAC mounted the power-steering pump and alternator inline behind the oil pump. Since it’s driven only at half engine speed, the alternator was upgraded to provide enough juice for the electric fuel pump.

“Most of the time the engine is running between 3,000 and 6,800 rpm,” says Rankine, noting that rules require a 7,200 rev limit.

On the exhaust side, HPD provides a stainless-steel adapter between the cylinder, which has an integrated cast exhaust manifold, and a spec 3-inch stainless-steel pipe that exits on right side. If local track rules require noise abatement, a muffler can be mounted to the end of the pipe – but alterations to the pipe itself are not allowed.

Another example of a Honda-powered Midget.

The Honda engine will bolt directly into an existing Ford car as the bellhousing patterns are identical. USAC says there are 80 to 120 racers at any given time in the HPD Midget program, and boosting that number should be easy with simplified tuning and cleaner plumbing lines.

“We expect to see [Honda engine count] increase next year. We have 10 motors in production right now,” sums up Rankine. “It’s a lot easier for the average guy to race with this engine, as opposed to the mechanical fuel injection where you had barrel valves, by-passes, secondaries – just a lot of things that needed adjustment. The Honda takes that out of the equation for racers who aren’t experienced with that.”