Honda Power Unit

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
MrPotatoHead
55
User avatar
Joined: Thu Apr 20, 2017 6:03 pm
Location: All over.

Re: Honda Power Unit

Post by MrPotatoHead » Mon Feb 12, 2018 7:26 pm

roon wrote:
Mon Feb 12, 2018 7:19 pm
MrPotatoHead wrote:
Mon Feb 12, 2018 7:14 pm
roon wrote:
Tue Jan 30, 2018 11:58 pm


Or 100% of them would be really big ones. Recall Wazari did elude to a "short" crankshaft last year, never specifying short in height, or short in length. Height-wise, the "shortest" crankshafts would be flat-plane and 0-degee. I don't know if exhaust frequency analysis bore this out or not.
The rules are quite clear on the number of journals the crank must have.
Yes, three conrod bearing journals. How does that relate to my quote? Throw orientation doesn't alter journal count.
Just related to the "short" crank talk from last year that's all.
Forgive me I have been quite busy and I'm weeks behind on catching up :-)

roon
212
Joined: Sat Dec 17, 2016 6:04 pm

Re: Honda Power Unit

Post by roon » Mon Feb 12, 2018 7:33 pm

MrPotatoHead wrote:
Mon Feb 12, 2018 7:26 pm
roon wrote:
Mon Feb 12, 2018 7:19 pm
MrPotatoHead wrote:
Mon Feb 12, 2018 7:14 pm


The rules are quite clear on the number of journals the crank must have.
Yes, three conrod bearing journals. How does that relate to my quote? Throw orientation doesn't alter journal count.
Just related to the "short" crank talk from last year that's all.
Forgive me I have been quite busy and I'm weeks behind on catching up :-)
No worries. :) Actually, the dubiously useful concept I presented last year to satisfy this wording had a short (length) single throw crankshaft that still incorporated three journals. Just image a journal that contains three stepped diameter changes, or simple circumferential cuts to delineate three bearing surfaces. Goal was to fit a coaxial MGUK in front of the crankshaft and within the block. This is 100% not what was occuring in that actual engines. :lol:

MrPotatoHead
55
User avatar
Joined: Thu Apr 20, 2017 6:03 pm
Location: All over.

Re: Honda Power Unit

Post by MrPotatoHead » Mon Feb 12, 2018 10:32 pm

roon wrote:
Mon Feb 12, 2018 7:33 pm
MrPotatoHead wrote:
Mon Feb 12, 2018 7:26 pm
roon wrote:
Mon Feb 12, 2018 7:19 pm


Yes, three conrod bearing journals. How does that relate to my quote? Throw orientation doesn't alter journal count.
Just related to the "short" crank talk from last year that's all.
Forgive me I have been quite busy and I'm weeks behind on catching up :-)
No worries. :) Actually, the dubiously useful concept I presented last year to satisfy this wording had a short (length) single throw crankshaft that still incorporated three journals. Just image a journal that contains three stepped diameter changes, or simple circumferential cuts to delineate three bearing surfaces. Goal was to fit a coaxial MGUK in front of the crankshaft and within the block. This is 100% not what was occuring in that actual engines. :lol:
It is an interesting concept for sure.
I'm somewhat surprised no one has tried to integrate the MGU-K in the block in just such a fashion.
The only reason not to would be that it would likely increase the height of the crankline / CoG in the block vs sitting alongside.

roon
212
Joined: Sat Dec 17, 2016 6:04 pm

Re: Honda Power Unit

Post by roon » Mon Feb 12, 2018 10:55 pm

MrPotatoHead wrote:
Mon Feb 12, 2018 10:32 pm
I'm somewhat surprised no one has tried to integrate the MGU-K in the block in just such a fashion.
The only reason not to would be that it would likely increase the height of the crankline / CoG in the block vs sitting alongside.
I'd add that a spur gear connection would be lighter/more compact than a planetary gearset, as another reason against it, if a speed reduction and compact motor design is maintained. Seems you're implying a direct-drive K would need to be larger diameter motor.

Tommy Cookers
417
Joined: Fri Feb 17, 2012 3:55 pm

Re: Honda Power Unit

Post by Tommy Cookers » Mon Feb 12, 2018 11:09 pm

a direct drive K would be bigger torque/diameterwise and much bigger inertiawise than the present K and slower responding
and slower responding than the ICE - this would increase the gearshift time (the time at reduced torque)

for any given power an axially compact (pancake) K will be slower responding than the present long and slim type

Mudflap
73
User avatar
Joined: Wed Feb 17, 2016 8:36 pm

Re: Honda Power Unit

Post by Mudflap » Mon Feb 12, 2018 11:53 pm

Im not sure TC, the K inertia as seen at the crank is 10x the actual rotor inertia assuming a gear ratio of 3.3.

Surely the inertia of a direct drive pancake rotor will be higher but it won't exceed the effective inertia of a geared motor unless you treble the rotor radius.
How much TQ does it make though?

godlameroso
204
User avatar
Joined: Sat Jan 16, 2010 8:27 pm
Location: Miami FL

Re: Honda Power Unit

Post by godlameroso » Tue Feb 13, 2018 12:29 am

ringo wrote:
Mon Feb 12, 2018 5:09 am
if i were to hazard a few guesses:
i don't think the valve seat is perpendicular to the valve stem due to the need to have a very vertical and straight intake run into the cylinder.
the intake valves in the cylinder are also different sized
the exhaust valves are also different sized.

interesting nugget about the jet combustion going to the walls first before ignition of the lean mixture.
There are different approaches to intake port geometry, depends what type of conditions you're trying to achieve. For example if you are trying to induce tumble to the intake air, you would use more of a "ramp" style intake port, where you increase the surface area of the port floor vs the roof.

A lot of this has to do with the intake system. The air box, the internal geometry of the plennum, geometry of the runners. The plumbing U isn't just good for the exhaust side :wink:
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

Tommy Cookers
417
Joined: Fri Feb 17, 2012 3:55 pm

Re: Honda Power Unit

Post by Tommy Cookers » Tue Feb 13, 2018 12:32 am

isn't the present K machine arrangement chosen to optimise the response in shifting ?
didn't they chose gearing rather direct drive for that reason ?

and they don't want a low torque 120000 rpm H machine and a high torque 12000 rpm K machine

Mudflap
73
User avatar
Joined: Wed Feb 17, 2016 8:36 pm

Re: Honda Power Unit

Post by Mudflap » Tue Feb 13, 2018 12:51 am

From an inertia perspective the best setup would be a very low speed machine turning slower than the crank.

I was not debating the motor performance.

Regarding the previous valvetrain discussions - Honda's 990 cc motogp engine revved to 16000 rpm with single springs and buckets (which are known to have the highest friction compared to roller followers and fingers and up to 30% higher inertia compared to fingers).

I wonder if valve rotation can be achieved with PVRS. Given the durability requirements and the extreme exhaust valve temperatures valve wear must be quite hard to tackle. Maybe there is an advantage to springs after all ?
How much TQ does it make though?

PlatinumZealot
304
User avatar
Joined: Thu Jun 12, 2008 2:45 am

Re: Honda Power Unit

Post by PlatinumZealot » Tue Feb 13, 2018 2:23 am

Inertia is a trade off..
Inertia of the geartrain
Inertia of the motor

One will be sacrificed for the other.

If you use a one to one ratio with a pancake motor. That motor will spin slower, down to engine speeds. Slower spining motors require larger magnetic flux that requires bigger ferrite cores Increasing weight and inertia.

It is lighter and i reckon much less inertia to use a geared motor.

godlameroso
204
User avatar
Joined: Sat Jan 16, 2010 8:27 pm
Location: Miami FL

Re: Honda Power Unit

Post by godlameroso » Tue Feb 13, 2018 2:44 am

Mudflap wrote:
Tue Feb 13, 2018 12:51 am
From an inertia perspective the best setup would be a very low speed machine turning slower than the crank.

I was not debating the motor performance.

Regarding the previous valvetrain discussions - Honda's 990 cc motogp engine revved to 16000 rpm with single springs and buckets (which are known to have the highest friction compared to roller followers and fingers and up to 30% higher inertia compared to fingers).

I wonder if valve rotation can be achieved with PVRS. Given the durability requirements and the extreme exhaust valve temperatures valve wear must be quite hard to tackle. Maybe there is an advantage to springs after all ?
Do you suppose the high exhaust temperatures that produce NOx also contribute to valve seat recession?
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

Mudflap
73
User avatar
Joined: Wed Feb 17, 2016 8:36 pm

Re: Honda Power Unit

Post by Mudflap » Tue Feb 13, 2018 12:11 pm

godlameroso wrote:
Tue Feb 13, 2018 2:44 am

Do you suppose the high exhaust temperatures that produce NOx also contribute to valve seat recession?
Absolutely, other than material tribological characteristics valve recession is mainly driven by temperature, seating velocity (it should be kinetic energy at closing really but for reasons unknown seating velocity is still used in the automotive industry) and to a lesser extent seat angle.

Some argue that peak cylinder pressure is also a factor but I'm not so sure.

I'd be very curious to know how they mitigate seat recession since the tradition seat materials used in motorsport have been relatively soft copper beryllium alloys - I imagine they must take quite a beating in an F1 engine.
How much TQ does it make though?

Tommy Cookers
417
Joined: Fri Feb 17, 2012 3:55 pm

Re: Honda Power Unit

Post by Tommy Cookers » Tue Feb 13, 2018 1:20 pm

traditionally SI engines have little or no oxygen in the exhaust gas
these engines have lots and so the oxidation potential might seem to be greater than otherwise
but the exhaust gas will be rather cool

high-strength copper beryllium can be quite hard and it could be mechanically hardened in situ
intentionally by use of dedicated rolling equipment and incidentally by valve impact
it would be rather elastically compliant under impact
it can go to 10000 microstrain elastically (at room temperature)
it will run cooler than the usual valve seat insert materials
in typical use it's pretty corrosion resistant

MrPotatoHead
55
User avatar
Joined: Thu Apr 20, 2017 6:03 pm
Location: All over.

Re: Honda Power Unit

Post by MrPotatoHead » Tue Feb 13, 2018 1:36 pm

Tommy Cookers wrote:
Tue Feb 13, 2018 1:20 pm
traditionally SI engines have little or no oxygen in the exhaust gas
these engines have lots and so the oxidation potential might seem to be greater than otherwise
but the exhaust gas will be rather cool

high-strength copper beryllium can be quite hard and it could be mechanically hardened in situ
intentionally by use of dedicated rolling equipment and incidentally by valve impact
it would be rather elastically compliant under impact
it can go to 10000 microstrain elastically (at room temperature)
it will run cooler than the usual valve seat insert materials
in typical use it's pretty corrosion resistant
If only the rules didn't prohibit Copper Beryllium seats now ;-)

Tommy Cookers
417
Joined: Fri Feb 17, 2012 3:55 pm

Re: Honda Power Unit

Post by Tommy Cookers » Tue Feb 13, 2018 2:05 pm

this would be about 2.5% Beryllium 97.5% Copper

I would have guessed that's permitted
(the rules being written around permitting this material but prohibiting AlBeMet type materials of eg 50% Beryllium ?)