Honda Power Unit Hardware & Software

[ncassi22]

Vibration can be dampened by changing the type of seal on the valve cover. Maybe the secret to stabilizing combustion is in the quench area where the bore and cylinder head mate.

Here's an old Honda patent discussing increasing the stiffness without massively increasing thickness/size of the valve cover. Just thought it would be interesting. http://www.freepatentsonline.com/EP2679792A1.html

[Webber2011]

these crankshafts have dampers to reduce torsional vibration but will still be twisting through about +0.25 deg to -0.25 deg about 200 times per second
generating high stresses that would cause fatigue failure after maybe 200 hours
the mechanical effects due to the MGU-K (geared to the crankshaft) will be integrated into the crankshaft/damper system by design
but the MGU-K is presumably exposed to (some of) the crankshaft's torsional vibration
this vibration is presumably causing some kind of vibratory stress damage/fretting to the electrical insulation of conductors in the rotating parts

That's something I'd like to know more about mate !
Could you explain in a bit more detail the crankshaft damper system ?
I find that fascinating !

at this moment I assume modern race engines (even V6s) still have dampers as all road cars and performance road cars do
eg http://www.atiracing.com/products/dampe ... _dinan.htm
though they don't all use the conventional elastomer-mounted inertial mass type, other types are available
eg the Cosworth DFV seems to have been initially without a damper, but introduced it in 1971 as the rpm was raised
the Cosworth CA has 'a big viscous damper on the back of the crankshaft' (and 13 other dampers)
some other rival NA F1 engines used pendulum-type dampers on their crankshaft torsionals
and Cosworth says 'in F1 it is a case of using the best firing order and fixing the torsionals'
http://www.f1technical.net/articles/18858

the damping is lighter than suspension damping (a crankshaft has some natural damping from internal and external friction)
but is enough to reduce the angular deflection by at least half
eg the 60s Indy Ford crossplane V8 had +-0.21 deg damped at normal peak power 7300 rpm
but undamped +-0.36 deg (4th order) at 6100 rpm and over 0.5 deg (3rd order) at 8000 rpm
(btw if made of mild steel this crankshaft twisted to 0.21 deg wouldn't return to 0 deg unloaded, if cast iron it'd break before reaching 0.21 deg)
(btw 2 this engine was used (destroked from 4.2 to 3 litres) in 1967 F1 by McLaren
the destroking was done by machining much away much of the crankpins and metal spraying (Stellite) new metal in the right place
over-ported and over-valved even at 4.2 litres it was a disaster at 3 litres, slightly relieved by using smaller bellmouths and throttle bodies
the days of 'men in sheds' ! - maybe they should have V6'd it ? eg by leaving 2 pistons on the bench? )


due to its position we would expect the MGU-K to be exposed to some small fraction of the torsional vibration at engine frequency
but a bigger fraction of the torsional vibrations at higher frequencies eg 3rd order etc, these are anyway the greater amplitudes
and the MGU-K angular displacement is about 3.5x the crankshaft's as this is the gearing ratio

Excellent !
Thank you Sir

The first link you posted has a great explanation, and is just what I was looking for.
Detailed enough to tell me what I needed to know without frying my brain

As an aside, I know it's off topic but maybe not too much.

I have an Ex Girlfriend that I'm still great friends with and one day she came to visit.
As she drove into my drive way (which was quite long, as I was living on a rural property), she lost all power steering, so parked it right there.

We walked down and when I popped to bonnet expecting a belt or something, I found the whole crank pulley had just fallen off ! !
The bolt had come loose, and it had worked it's way off the shaft at the very moment she turned in.

Thank God it didn't happen on the freeway !

So we bought another, got some new belts, and she was on her way again.
(That was once I found a suitable key at work, because would you believe when you purchase a new pulley they don't supply the key ?)

The reason I was so interested in your post was because, and this is the honest truth I swear, it was a Honda

[ringo]

Tommy Cookers,

Any evidence to suggest honda's reportedly shorter crank ties into their issues?

[isullivan]

Any evidence to suggest Honda is using camless heads ? Is it even allowed in F1 ?

[wuzak]

Any evidence to suggest Honda is using camless heads ? Is it even allowed in F1 ?

No evidence that Honda are using camless valve actuation.

And there doesn't appear to be any rules against it.

[Tommy Cookers]

......but the MGU-K is presumably exposed to (some of) the crankshaft's torsional vibration

Surely the MGUK is driven at the flywheel/gearbox end of the crankshaft where the torsional displacements are much less severe?

As there is no flywheel per se, the inertia at the rear of the engine is low so displacements will not be as low as you think because the node of the first torsional mode shifts towards the front of the engine. Having said that, I am pretty sure Ferrari used a rear driven MGUK at some point. Honda's seemed to be front driven from a few pictures I have seen around here somewhere.

Rules say it must be geared directly to the crank. It's not transmission side, but may be geared via a flywheel or something to that effect. .....

Nothing stopping them from sticking a damper on the MGUK

fwiw I assume the MGU-K is driven at the 'flywheel' end of the crank (and that torsionals are less there) ..... but as M says .....
there is no flywheel - and what we loosely regard as equivalent to the flywheel is the clutch ....and .....
the clutch is in the gearbox ie effectively more remote from a traditional and textbook notion of 'flywheel' position
gearing the K at 3.5x crank speed might not be ideal in this regard
so things are less than clearcut

as others have said .....
crank stiffness is fixed at a conservative level by rules on minimum pin and main journal diameters ? (hollowing could evade this, but why do it ?)
block and head/cambox stiffness is vital (as Honda and Cosworth have found earlier)

[Tommy Cookers]

From Autosport.com: http://www.autosport.com/premium/featur ... al-f1-test
Honda has spent much of the winter working on advanced combustion technology in its bid to close the gap to the leading manufacturers, but the combustion process it has created is so unstable the engine will not hold together.

Ok this clears up a number of things.
First of all combustion stability takes a hit the higher it goes above stoichiometric. The stability is measured by a number of means. Statistically by the missfire events. The consistency of peak pressure.. The consistency of the deflagration.. Temperature patterns, to name the little i know.
It simply means to me that the misfires are what are causing the vibrations. And there seems to be some detonations in the mix.
Did Honda go ahead and design their own jet ignitor? The injector is showing inconsistent firing and seems mechanically weak.
Is the castrol fuel wreaking havoc on Honda and to some extent Renault?

the above sounded worth repeating to me (so I did a bit of cropping)

and in principle not unrelated ? .....
in modern NA F1 (Ferrari) there was inconsistency/instability of combustion in some cylinders at high rpm (alleviated by richening overall)
these effects (from the induction plenum behaviour) related to firing order
as Cosworth found, abandoning their established V8 order for a better order with the CA
though this better firing order for even and consistent induction was worse for crankshaft design
if the induction action resembles an expert playing the xylophone the order is good for the crankshaft but bad for induction
if the induction action resembles a beginner playing the xylophone the order's good for induction but bad for the crankshaft
induction plenum effects obtain whether NA or boosted
ok without cylinder cutting or real weirdness there's only 2 orders possible in our V6 (the two banks doing the same thing, or not)

[RS200E]

Fastforward to 2004 and Honda became quite handy, finishing 3rd in the WDC and 2nd in the WDC against a dominant Ferrari. The 2004 engine was reportedly the most powerful and I remember it sounded amazing! So loud almost too loud.

Yes!! I remember the volume and the nature of the Honda sound was very different from every other engine. It was a much sharper and louder noise. Why?? Were they using direct injection then and everyone else was not?

https://youtu.be/YPzlOhAWU_Q

[godlameroso]

Given the variable intake trumpets, and MGU-H could there be a compromise between good induction, exhaust pulse efficiency, and crankshaft harmonics, buried somewhere in the weird? Using cylinder skipping perhaps? Some weak HCCI so the skipped cylinder isn't useless, or perhaps setting up a better more powerful combustion on the next cycle?

[wuzak]

Fastforward to 2004 and Honda became quite handy, finishing 3rd in the WDC and 2nd in the WDC against a dominant Ferrari. The 2004 engine was reportedly the most powerful and I remember it sounded amazing! So loud almost too loud.

Yes!! I remember the volume and the nature of the Honda sound was very different from every other engine. It was a much sharper and louder noise. Why?? Were they using direct injection then and everyone else was not?

I can pretty much rule that out since direct injection was banned at the time.

[tom101]

Spanish press published
2017 Honda engine was running with 50hp less than 2016 spec.
(Detuned of course)

Also vibrations causes electrical problems.

http://soymotor.com/noticias/lobato-mcl ... 016-931184

[tom101]

And talks about weight, Honda engine is lighter than Mercedes and Ferrari.

[AmateurExpert]

And talks about weight, Honda engine is lighter than Mercedes and Ferrari.

Seems like speculation and not fact. It's not in the written article, so I presume he mentions this in the video. Did he cite his sources? Manufacturers aren't exactly forthcoming with sensitive technical details such as engine weights, and certainly not to the depth of detail that's necessary to ensure apples-to-apples comparisons.

[proteus]

Fastforward to 2004 and Honda became quite handy, finishing 3rd in the WDC and 2nd in the WDC against a dominant Ferrari. The 2004 engine was reportedly the most powerful and I remember it sounded amazing! So loud almost too loud.

Yes!! I remember the volume and the nature of the Honda sound was very different from every other engine. It was a much sharper and louder noise. Why?? Were they using direct injection then and everyone else was not?

https://youtu.be/YPzlOhAWU_Q

If im not mistaken, the japanese engine manufacturers allways produced higher RPM engines, especially i noticed that in cars on the dashboard, the limiters red zone was defined much higher than in european manufacturers cars, right from the smallest cars up.

[RS200E]

Yes!! I remember the volume and the nature of the Honda sound was very different from every other engine. It was a much sharper and louder noise. Why?? Were they using direct injection then and everyone else was not?

https://youtu.be/YPzlOhAWU_Q

If im not mistaken, the japanese engine manufacturers allways produced higher RPM engines, especially i noticed that in cars on the dashboard, the limiters red zone was defined much higher than in european manufacturers cars, right from the smallest cars up.

Yeah was thinking that too. Was a big thing back then to get more revs.