Norma M20 FC Engine Development – 2.3L Stroker Honda K20 | Willow Springs 2026 Performance

We have been developing the Honda K20 engine inside our naturally aspirated Norma M20 FC for many years now. Recently we started running into engine longevity issues with the valvetrain that took motor life down to under 10 hours, which isn’t acceptable for us. We target at least 30 hours before rebuilds.

We were seeing valve stretch and seat wear, pointing to loss of control at high RPM.

Valvetrain Changes

After investigating and getting input from Honda specialists, we decided to remove VTEC to reduce valvetrain weight. We are now running the Ferrea roller rocker setup:
https://dragcartel.com/products/ferrea-k20a-roller-rocker

The goal was to reduce mass and improve control at high RPM. Removing the VTEC mechanism simplifies the rocker assembly and reduces inertia, making it easier for the springs to keep the valves stable at speed.

This was a reliability-driven change that ended up improving top-end performance.

Dyno Development

With this setup:

• We lost some torque below ~8500 RPM
• Gained power above 8500 RPM

We tested up to 9600 RPM on the dyno, which is about as far as we’re comfortable going on this stroked K20. The engine wants to keep making power beyond that, but rod and bearing life become the limiting factor.

We’ve set:

• Rev limiter: 9600 RPM
• Shift point: ~9100 RPM

Net result: better power where the car actually lives on track.

Willow Springs Performance

Willow Springs is a power track. Peak horsepower matters, especially on the straights and into Turn 8.

We were able to run:

• 1:17.0 lap time (our lap record at this track)

This was on heavily heat-cycled Goodyear tires and with traffic. With clean laps and fresh tires, we believe low 1:16s are achievable. We were surprised that the loss in low end torque we saw on the dyno did not have a big effect on the track performance of the car. Since this engine lives at such RPM we didn’t notice any decline in performance from the torque reduction, in fact the car almost was easier to modulate in throttle transitions due to the VTEC being disabled.

Trackside

A lot of time this weekend was spent working through setup, testing changes, and just enjoying being at the track.

Josephine and Gwen were there, along with crew chief Matthew Delaney’s kids. It made for a fun weekend outside of the driving.

Podium

Strong result and a good validation of the direction we’re heading with the car.

Fastest Lap

Acknowledgements

Big thank you to everyone involved:

• Shane T (https://motorsportcontrol.com/) – Motec M800 setup
• Colin Mason – harness and electronics

We are now fully rewired and running ECU Master on the power side, no longer using the original Norma electronics.

The engine is breathing well at high RPM with a heavily modified head and intake system, while still using the standard Norma header.

Final Thoughts

This change was focused on improving reliability at high RPM while maintaining strong top-end power.

We’re don’t have 30 hours on this engine yet, but we will be doing oil analysis and a valve adjustment this week to see if we see any signs of valve stretching at this high rpm. The oil analysis will allow us to see if we have significant bearing wear and need to reduce our RPM range.

Next step is validating durability over longer run cycles.