March 15, 2024 - USAC has officially approved the all-new Modified World Formula, and R.P.N. Motorsports is proud to announce we are ready to deliver this exciting new engine to racers. We have been hard at work testing and tuning the new engine in our shop and on the race track, and the results are outstanding.
USAC Approved - Ready to Race
Engine Features
- Based on the proven World Formula platform
- Modified cylinder head with improved flow
- Performance camshaft profile
- High-compression piston
- Billet connecting rod
- Precision balanced rotating assembly
- RPN proprietary machining and blueprinting
Development & Testing
R.P.N. Motorsports has invested over 500 hours of dyno testing and countless hours of on-track testing to develop the Modified World Formula package. Our goal was to create an engine that delivers maximum power while maintaining the reliability that RPN engines are known for.
Dyno testing at RPN
On-track validation
Precision assembly
Dyno Results
Our Modified World Formula engine shows significant gains over the stock World Formula:
| Engine | Peak Horsepower | Peak Torque | RPM Range |
|---|---|---|---|
| Stock World Formula | 8.5 HP | 8.2 lb-ft | 4,500 - 5,500 |
| RPN Modified World Formula | 10.8 HP | 9.6 lb-ft | 5,000 - 6,200 |
| Gain | +2.3 HP (27%) | +1.4 lb-ft (17%) | +700 RPM |
Track Testing Results
We tested the Modified World Formula at multiple tracks with experienced drivers. The feedback has been overwhelmingly positive:
"The power increase is immediately noticeable. The engine pulls harder off the corners and carries that power down the straightaway. It's going to be a game-changer for the class." - Test Driver
Lap time comparisons at a typical 1/16 mile track showed an average improvement of 0.3 to 0.5 seconds per lap compared to a well-prepared stock World Formula.
Class Rules & Eligibility
The Modified World Formula is approved for competition in USAC-sanctioned events and is expected to be adopted by other organizations soon. The engine is designed to fit within the rules for "Modified" or "Open" World Formula classes. Key specifications:
| Displacement: | 206cc (stock) |
|---|---|
| Carburetor: | Stock World Formula carburetor (modified permitted) |
| Ignition: | Stock or approved aftermarket |
| Cooling: | Air-cooled |
| Fuel: | Pump gas or racing fuel (per class rules) |
Always check your local track and series rules for specific requirements.
Availability & Pricing
The RPN Modified World Formula engine is available for immediate order. We offer several package options:
| Package | Includes | Price |
|---|---|---|
| Complete Engine | Fully assembled, dyno-tested, ready to race | $1,895 |
| Short Block | Modified block, crank, rod, piston (less head, carb, ignition) | $1,195 |
| Cylinder Head Package | Modified head, cam, valves, springs | $895 |
Core exchanges are available for customers sending in a complete World Formula engine. Contact us for details.
Customer Support & Technical Assistance
As with all RPN engines, every Modified World Formula comes with our commitment to customer support. We're available to answer questions about setup, gearing, and maintenance. We also offer rebuild services and replacement parts.
Ready to order or have questions?
Contact RPN Motorsports or call (937) 371-2572
About RPN Motorsports
R.P.N. Motorsports has been building championship-winning engines since 2007. Located in Brownsburg, Indiana, we specialize in the development and building of racing engines for quarter midgets, karts, and micro and mini sprints. All design and machine work is done in-house, along with extensive research and development testing.
Press Contact: Andy Nock, (937) 371-2572, [email protected]