Honda engines are unreliable - we know that from the McLaren years
Much of this is due to installation problems and unreasonable packagaing demands of McLaren. McLaren couldn't even get the Renault to run correctly in 2018 winter testing, whereas the Toro Rosso was flawless with the newly installed Honda in 2018 winter testing.
Honda are very open about technical details compared to the other manufacturers, please follow the link and read for yourself about the technical details of the ongoing development of the Honda F1 power unit: https://www.reddit.c...us_1517_from_a/
McLaren developed MP4-30 with size zero concept in mind. What was lost in power was supposed to be gained by aerodynamic performance.
We didn't fully understand the difficulty of developing a PU. This lack of understanding played a role in our accedding to the chassis' demands. Once out on track we realised there were a lot of issues.
The turbocharger's position inside the V-bank limited its size. It's difficult to increase efficiency without making it larger. With the turbochager in the V-bank, the induction system was orientated quite forcefully. I was shocked by the complexity of the components of the (allowed) variable intake trumpet length system being placed in such a small space when I first saw it.
In the 2015 RA615H, packaging needs forced the intake plenum to be flat. The focus for the 2016 RA616H was an improvement of the cramped induction system. After negotiations with McLaren, the allocated space for the engine increased somewhat, allowing the intake plenum to be raised 30mm. The engine could not be revamped fully because of the token system.
This thread is about the two mighty, sporting and much admired Red Bull teams with Honda. As you know the RA17H, with lifting of token system, was a whole new concept of power unit and therefore had initial troubles (particularly regarding oil starvation from the constrained shape of the engine oil tank that was possible, for the dry sump system).
The RA18H has been a development of the RA17H and has been relatively reliable. Indeed the extra space allowed by Toro Rosso for the RA18H's intake and exhaust manifolds (compared to the RA17H) already produced an immediate gain in horsepower! Since the 2018 Toro Rosso gearbox was similar to the 2017 one, Toro Rosso also provided a gearbox for Honda to test in conjunction with the power unit, which may have helped with the relatively smooth transition.
Edited by V8 Fireworks, 12 January 2019 - 20:45.