Honda Power Unit Hardware & Software

[kfrantzios]

Formula 1 bosses are doing 'everything they can' to keep Honda in the championship beyond the end of the 2017 season.

Why not allow them extra testing days at the end of this year and early in 2018.

Maybe because the other teams wouldn't let them? I wonder what would have happened if FIA concluded that Honda was out of the 3% margin.

[harjan]

Haha- do you really assume Honda is within that limit? FIA concluded Mercedes, Ferrari and Renault are within 0.3 sec of engine performance around Barcelona. And in race trim this is probably about right.

Honda is easily 0.5-1 sec of Renaults pace.

[63l8qrrfy6]

He also mentioned something I hadn't heard before... In response to the the question of what the main issue is with the PU:
"It's friction, there's a lot of friction in the engine and as we know, friction is not what you want, that's costing us power, but they are trying very hard to get that sorted and they have developments in the pipeline so we will have to see what they have come up with and take a decision from there".

Interesting point. That's likely the root cause of the vibration issues. If Spec 4 delivers new pistons, CC, heads whatever other internal changes are rumoured, that really could lift their game. Gut feeling here, but I think Spec 4 could rear it's head in Malaysia, ahead of a hopefully stronger showing in Japan (an important home race for Honda and their pride) than last year.

How is friction the root cause?
Friction leads to energy dissipation as heat - if anything it would help dampen vibration.

Energy disipation as heat = energy lost. That, on an efficient formula like this is a shoot in your own foot, apart from the increased temperature wich increase cooling requirements, wich also add drag to the car

You might want to read the entire post - the discussion is about vibration.

[dren]

I definitely know the issue and all I can say is "I knew it"....I would be out of line to say at this time but here are some points to ponder. Piston rings are very low tension, so.........Extremely low viscosity oil is used, so............Bearing materials are state of the art and tolerances are very carefully measured so.............Plenty of experience building high revving engines (20K RPM +) and these engines rev at a relatively low RPM's so............. So where would there be possible friction issues outside the engine block components and NOT the MGU-H unit or parts associated with the MGU-H? (I am not saying the MGU-H unit doesn't have friction issues but...........)

This would seem to leave the MGU-K, or possibly accessories such as oil pump, water pump, etc.

I think someone previously said the MGU-K had a ~3:1 ratio of rotational speed relative to the crank. So it's spinning all day long at 30,000 to 35,000 rpm. The gear-drive connection between MHU-K and crank puts plenty of side force on the MGU-K shaft, and if you look at the shaft force vs. time closely you will probably see some force variation due to the individual gear teeth going in and out of mesh. Meanwhile, the block and MGU-K itself are being loaded severely because they are structural members thru the middle of the car, so the dimensional stability is not what you want.

The engine will go thru abrupt and brutal step-changes in rotational speed during gearshifts (rpm step-up with downshift, rpm step-down with upshift). This leads to early season MGU-K failures? One of the plausible countermeasures is more/larger/stronger bearings on the MGU-K. Makes friction worse.

If the MGU-K is spinning at 3x engine speed, then its rotational inertia will effectively be 9x higher on a per unit basis. So that's a lot of inertia to handle, especially during the abrupt shifts.

OK, so easy to see lots of potential problems with the MGU-K friction, but why does the Honda seem to have the reliability and friction problems? Does Honda turn the MGU-K faster than other power unit manufacturers? Do they mount it or drive it differently?

It could be something within the head and whatever combustion process they are currently utilizing requiring specific cams, valves, etc. This should be the area that's revised for spec 4.0.

It's the only area that I can think of that might be different from past racing engines. All of the ancillaries should be similar to the older engines with marginal improvements.

I'm assuming the turbine and compressor are a non-issue.

[tok-tokkie]

I was very surprised, and unbelieving, about the claim that it is friction in the Honda engine that is the problem.
Do they have TJI or something similar? I thought that was the root of their problem.
But in the 2 stroke thread last year Manolis posted a calculation of the power absorbed by the valve gear of a Ducati 1300cc Panigale V-twin engine. It was 45kW. Link to thread viewtopic.php?f=4&t=10966&start=990 Post of 2016/07/28

[Sasha]

Clues...

Wazari in his post stated "I knew it"

Wazari's consulting area is CC and Turbocharging.

HRD bosses didn't pick his teams CC design(because of weight).

Where is Honda's major problem(clue CC).

My guess the friction is in the heads.

[63l8qrrfy6]

2017:
2+0+1+7 = 10 hp
The exact amount lost in 'head friction'

[NL_Fer]

Are we actually talking mechanical friction or friction between team/manufacturer?

[ArcticWolfie]

Can somebody explain why it is so difficult to solve the friction in the engine? I mean 11k~15k RPM engines isn't new science (the V10 ran over 18k RPM).
So what could be so difficult to solve/fix...

[Maritimer]

Can somebody explain why it is so difficult to solve the friction in the engine? I mean 11k~15k RPM engines isn't new science (the V10 ran over 18k RPM).
So what could be so difficult to solve/fix...

I would assume it relates to how strong the return springs on the valves are.

[Pedrohf]

Can somebody explain why it is so difficult to solve the friction in the engine? I mean 11k~15k RPM engines isn't new science (the V10 ran over 18k RPM).
So what could be so difficult to solve/fix...

Makes sense.
Probably the friction comes from the MGU-K shaft. Too much torsion due to lack of rigidity from the ICE? That would explain the bearing failures (maybe that's why SPEC4 is heavier?)

(sorry for my english)

[63l8qrrfy6]

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.

Main and big end bearing friction drops sharply past a certain clearance, however too large a clearance compromises the oil film thickness. Similarly a lower L/D bearing ratio decreases friction but increases the specific pressure (diameter is imposed by FIA). I suspect everyone still uses leaded bearings (either lead tin copper or lead indium) on copper lining, probably from the same supplier - so it's unlikely that the bearing friction varies greatly across manufacturers.

In 2013 I think Mahle proposed steel bushingless connecting rods for F1. These had a profile machined on the small end bore and could be DLC coated. The claim was that friction was reduced compared to a traditional copper bushed titanium rod.

[alexa]

More about updates

Honda introduced the specification 3.7 of its power unit in the McL32 in Monza. An improvement that Hasegawa confirms has boosted the horsepower of the propeller and that is centered in the turbocharger: "The point of improvement of the engine 3.7 is the turbocharger. The internal combustion engine is the same as version 3.6, but the maximum power is increases slightly due to the effect of this improvement.In several places, the expectation value is as specification 4 ".

In addition to the development in the turbocharger and the torque of the engine at low speed, he responsible for Honda in Formula 1 ensures that at Spa Francorchamps premiered a motor map for the classification that allows them to match the power of Renault: "During the test post race in Hungary we collected data that allowed us to launch a classification engine map in Belgium . Like Mercedes, it can only be used temporarily due to the overload that is submitted to the combustion engine, but can reach a power of up to 20 kW (26 hp) that allows us to match the same level as Renault . In Sakura resistance tests have been performed and it is being understood how much time can be used in the race. "

https://as.com/motor/2017/09/06/formula ... 69746.html

[bill shoe]

I was very surprised, and unbelieving, about the claim that it is friction in the Honda engine that is the problem.
Do they have TJI or something similar? I thought that was the root of their problem.
But in the 2 stroke thread last year Manolis posted a calculation of the power absorbed by the valve gear of a Ducati 1300cc Panigale V-twin engine. It was 45kW. Link to thread viewtopic.php?f=4&t=10966&start=990 Post of 2016/07/28

F1 used to have 40-valve engines revving near 20,000 rpm. Now they have 24 valve engines revving to ~ 11,000 rpm. I'm just guessing like anyone else, but valvetrain seems unlikely to cause excessive friction.

[j.yank]

More about updates

Honda introduced the specification 3.7 of its power unit in the McL32 in Monza. An improvement that Hasegawa confirms has boosted the horsepower of the propeller and that is centered in the turbocharger: "The point of improvement of the engine 3.7 is the turbocharger. The internal combustion engine is the same as version 3.6, but the maximum power is increases slightly due to the effect of this improvement.In several places, the expectation value is as specification 4 ".

In addition to the development in the turbocharger and the torque of the engine at low speed, he responsible for Honda in Formula 1 ensures that at Spa Francorchamps premiered a motor map for the classification that allows them to match the power of Renault: "During the test post race in Hungary we collected data that allowed us to launch a classification engine map in Belgium . Like Mercedes, it can only be used temporarily due to the overload that is submitted to the combustion engine, but can reach a power of up to 20 kW (26 hp) that allows us to match the same level as Renault . In Sakura resistance tests have been performed and it is being understood how much time can be used in the race. "

https://as.com/motor/2017/09/06/formula ... 69746.html

Well, if their level were at Renault but still lagging behind RdBull in qualifications, it means that McLaren chassis isn't too good.