Honda's chief engineer, Shintaro Orihara has given rare insight into the new engine to be introduced at Zandvoort.

The new engine follows the major car upgrade introduced in Hungary, and together it is hoped they will propel Aston Martin further up the grid.

Barely had a wheel turned than it was clear that, as was the case in 2015, the Japanese manufacturer had got it wrong. Other than the sheer lack of grunt, the Honda power unit has suffered a vibration issue which, other than affecting performance, has compromised reliability.

Such was the weakness of the Honda power unit, it's ADUO rating qualified it for the maximum two upgrades this season.

Orihara explains that the power unit's biggest weakness has been the ICE.

"Our engine performance is definitely poor compared to other manufacturers," he tells Motorsport.com. "So probably the most important point to improve now is our engine performance because the gap is quite huge.

"Without improving our combustion engine performance, the rest doesn't help," he continues. "Let's say, if we improve energy management, that doesn't help if the engine performance is poor. So now we purely focus on improving our engine performance. Once we achieve our target there, then maybe we can optimise some other small areas. But still our main focus point is the engine performance, the combustion engine.

"Our target is to get back to the racing field," he says, "to a situation where the 10 milliseconds or 20 milliseconds that we try so hard to find every weekend, can actually make a difference.

"We focused to improve engine performance, to make combustion faster," he says of the upgrade. It's kind of a secret, but I can disclose a little bit. We changed the pre-chamber to make combustion faster, and we also changed the piston shape to get good combustion. We modified some lubrication system to reduce friction. We had quite a big list to improve engine performance," he admits.

Asked about one of the most common complaints about the current engine, driveability, he says: "We developed our tools to optimise our driveability. We have made good progress and we were close to what we wanted to achieve. But when we introduce the spec 2 engine, the combustion characteristics will change significantly. Well, maybe not significantly, but there will be a big difference.

"Then engine behaviour will be changed in the cornering phase as well. So yeah, we need to develop our driveability again. With the car spec changing, cornering speeds will be much higher. And then demands on driveability will be changing as well.

"There has been big progress through this first half of the season," he continues. "We developed our optimised way for drivability. We will introduce our new engine and probably we need to do more work to improve driveability again, but now we know how we need to do it and where we should improve. That has been a big learning, and we can carry over that learning point to our B-spec engine."

Aston Martin ran the engine at the Hungaroring on a filming day following the Grand Prix, and while various figures have been speculated upon, Orihara is giving little away.

"I can't disclose the detailed number, but we have achieved our internal target," he said, according to F1i.com. "I'm confident in what the HRC Sakura factory guys achieved for the spec two engine," he added. "We are excited to bring a new spec engine to the Netherlands, and we will see where we are."