Honda Power Unit Hardware & Software

[fellowhoodlums]

That after so many fails, Honda doesn't use best/strongest bearings available is doubtful
Obviously, something is shattering the bearings... either vibrations are not completely eliminated, or something else could be in play

Discolouration mentioned....heat.

[Sasha]

Vibrations is Godzilla.(destroys everything it touches)

[godlameroso]

Vibrations is Godzilla.(destroys everything it touches)

Destroys seals, which in turn destroys bearings?

[MrPotatoHead]

Vibrations is Godzilla.(destroys everything it touches)

Destroys seals, which in turn destroys bearings?

I think I mentioned the seals failing a while back.
The bearings are not the root of the problem just where the problem ends up.

[godlameroso]

Vibrations is Godzilla.(destroys everything it touches)

Destroys seals, which in turn destroys bearings?

I think I mentioned the seals failing a while back.
The bearings are not the root of the problem just where the problem ends up.

Interesting, the Mercedes power unit also had trouble with its seals, which is why you see them belch oil clouds when they idle. The type of seal they ended up using leads to them burning oil.

[MrPotatoHead]

Destroys seals, which in turn destroys bearings?

I think I mentioned the seals failing a while back.
The bearings are not the root of the problem just where the problem ends up.

Interesting, the Mercedes power unit also had trouble with its seals, which is why you see them belch oil clouds when they idle. The type of seal they ended up using leads to them burning oil.

Sealing a shaft that spins at 125,000 rpm whilst also control air and fluid pressures in specific places is not as easy as some might think.

[bigblue]

Interesting, the Mercedes power unit also had trouble with its seals, which is why you see them belch oil clouds when they idle. The type of seal they ended up using leads to them burning oil.

Certainly it must be an indication of some particular design feature, it is very noticeable, even to a non-expert like me !

[DarkAlman]

Maybe this long shaft starts bending? causing wear/problems
TC&MGU-H being 1 package seems like not very good decision reliability wise

If they are using a clutch to disengage the turbine from the MGU-H like the Mercs do then the shaft isn't the length of the engine. It's probably two smaller drive shafts mounted end to end at the MGU-H.

[PhillipM]

Certainly it must be an indication of some particular design feature, it is very noticeable, even to a non-expert like me !

Graphite seals perhaps.

[trinidefender]

Maybe this long shaft starts bending? causing wear/problems
TC&MGU-H being 1 package seems like not very good decision reliability wise

If they are using a clutch to disengage the turbine from the MGU-H like the Mercs do then the shaft isn't the length of the engine. It's probably two smaller drive shafts mounted end to end at the MGU-H.

I was under the impression they don't and have not seen anything indicating that merc are using a clutch in their turbocharger/MGU-H

It was presented as an idea a few times years ago on this forum but if memory serves never really gained any traction as a viable option.

On another note if vibration in the turbocharger/MGU-H shaft itself is a problem (which I'm still not sure about) then can't flex couplings be used to change the resonant frequency of the shaft?

[Zynerji]

I'm surprised they are not simply drilling holes, tapping them, and putting heavier metal slugs in the holes. Kind of like a dampener.

I guess you would need to know where to drill, and what frequency to tune, but maybe they need a Luthier more than an engineer?

[MrPotatoHead]

Maybe this long shaft starts bending? causing wear/problems
TC&MGU-H being 1 package seems like not very good decision reliability wise

If they are using a clutch to disengage the turbine from the MGU-H like the Mercs do then the shaft isn't the length of the engine. It's probably two smaller drive shafts mounted end to end at the MGU-H.

What makes you think Mercedes are doing this?
And don't forget that you cannot decouple the compressor side of the turbo from the turbine side.

[PlatinumZealot]

Vibrations is Godzilla.(destroys everything it touches)

Do they measure and log vibrations in that location? It seems that no abnormalities showed up in the data (as said in the interview... So probably means the bad vibrations were accepted for the time but unbeknownst to them those acceptable vibrations were still causing small but accumative damage?

[Sasha]

This was MB's biggest headache with their PU,almost went back to a standard turbo.

[godlameroso]

At 125,000 rpm you're talking about a hell of a seal, the frequency just from the shaft is at least 125,000Hz, meaning whatever resonant frequencies are happening are beyond hearing range. I'd laugh if EM interference from the MGU-H is disrupting the combustion process as well. Maybe tripping up the ignition coils, or spark plugs. If the MGU-H is cast into the head as was rumored, and the MGU-H being a high voltage device it's possible.