Mudflap wrote: ↑06 Sep 2017, 22:11
They run higher fuel pressures with mechanical fuel pumps - those consume more power and cause more friction.
Geartrains potentially see higher loads and require larger bearings.
With the current cylinder pressures and the new oil consumption limits I would not be surprised if teams ran scraper rings. These require higher tension as they typically see lower energizing pressures.
Pneumatic valve pressures are likely lower as the speed has decreased therefore seal preload should be lower than V8s.
Exhaust valves open against higher pressures so camshaft radial loads have gone up and so have cam bearing and finger friction.
The valve "spring" pressure will likely be around the same as the v8 engines, if not higher, as the backside of the valve now has to resist the charge pressure pushing down trying to open the valves. You always have to increase valve spring pressure on a turbo engine.
Friction should be somewhat lower when compared apples to apples to the v8 engines because of the reduced rpm.
I wouldn't read too much into the friction comment.
There are 3 efficiencies in regards to the ICE:
Thermal Efficiency
Volumetric Efficiency
Mechanical Efficiency
The friction component of the Mechanical Efficiency is the smallest of the losses in an engine.
In these engines it "should" be around 5%. I would be socked if Honda were more than 1 or 2% away from where they need to be. Of course maybe things really are that bad!