Honda is keeping its cards close to its chest, but chief engineer Shintaro Orihara has offered the clearest glimpse yet of the manufacturer’s much-anticipated B-spec Formula 1 power unit.

The upgraded engine will make its competitive debut with Aston Martin at the Dutch Grand Prix, following Formula 1’s summer break. It arrives at a potentially important moment for a partnership that endured a difficult opening phase to the 2026 season.

Honda’s improvements are focused heavily on combustion. Orihara revealed that engineers have redesigned the engine’s pre-chamber to accelerate the combustion process, while the piston shape has also been altered to improve combustion quality.

The changes do not stop there. Honda has modified elements of its lubrication system with the aim of reducing friction, while Orihara hinted that the B-spec unit contains a much broader collection of refinements.

“We had quite a big list to improve engine performance,” he explained.

Those words will inevitably fuel speculation about the size of Honda’s performance gain. Reports had suggested the new engine could deliver as much as 50bhp, but Orihara was quick to play down that figure.

“I want to have that number, but that is a quite big number,” he admitted. “I don’t think… not the real number.”

Honda may therefore be resisting expectations of a revolutionary step, but the manufacturer says it has achieved its internal target for the upgrade.

The timing is particularly intriguing for Aston Martin. The team introduced an extensive 16-part upgrade package for its AMR26 at the Hungarian Grand Prix, with the revised chassis making an encouraging debut.

Now Honda has its chance to deliver the second half of the equation.

Following a filming day at the Hungaroring, where Aston Martin ran both its new chassis and Honda’s upgraded power unit, attention is firmly shifting towards Zandvoort.

For Orihara, the progress is about more than horsepower. Honda and Aston Martin have also strengthened their working relationship through a challenging season.

The B-spec engine could now provide a crucial opportunity to turn that improving partnership into results on track.