Honda Power Unit Hardware & Software

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
hurril
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Re: Honda Power Unit

Post by hurril » Fri Jan 12, 2018 8:15 am

ncassi22 wrote:
Fri Jan 12, 2018 7:22 am
The article mentions the Pneumatic valve system. It dindn't make clear whether the system was reduced in components/simplified to save weight or dumped for a springvalve system. Also it says something about injectors on the exhaust side??? Translation errors or something else?
It does mention using a spring-valve system instead.

Injectors on the exhaust side is nothing strange. The injector merely sits on the cylinderbank together with the exhaust valves instead of with the intake valves.

factory_p
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Re: Honda Power Unit

Post by factory_p » Fri Jan 12, 2018 2:15 pm

hurril wrote:
Fri Jan 12, 2018 8:15 am
ncassi22 wrote:
Fri Jan 12, 2018 7:22 am
Also it says something about injectors on the exhaust side??? Translation errors or something else?
Injectors on the exhaust side is nothing strange. The injector merely sits on the cylinderbank together with the exhaust valves instead of with the intake valves.
I would think everyone is running with the injectors on the exhaust side now.

At least it would make sense : in a lean combustion, mixture is a top priority and putting your injector on the exhaust side gives you much more freedom than anywhere else in the chamber: you are not disturbed by the intake valves opening during your injection phase, so you can design much better spray patterns.

bill shoe
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Re: Honda Power Unit

Post by bill shoe » Fri Jan 12, 2018 3:23 pm

ncassi22 wrote:
Fri Jan 12, 2018 7:22 am
The article mentions the Pneumatic valve system. It dindn't make clear whether the system was reduced in components/simplified to save weight or dumped for a springvalve system. Also it says something about injectors on the exhaust side??? Translation errors or something else?
I read it to mean Honda went from original pneumatic valve return to conventional coil springs to eliminate the pneumatic system weight. It says each coil spring is actually a triple-spring combo, which typically prevents any one spring resonance from dominating and provides light friction damping between springs. Current materials and dynamic modeling make conventional springs possible at revs where pneumatic used to be needed.

Would be interesting to know if other engines (Merc., Ferrari, Renault) use coil springs instead of pneumatic, and would be interesting to know if Honda sticks with coil-spring for the higher revs in 2021.

MrPotatoHead
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Re: Honda Power Unit

Post by MrPotatoHead » Fri Jan 12, 2018 3:46 pm

bill shoe wrote:
Fri Jan 12, 2018 3:23 pm
ncassi22 wrote:
Fri Jan 12, 2018 7:22 am
The article mentions the Pneumatic valve system. It dindn't make clear whether the system was reduced in components/simplified to save weight or dumped for a springvalve system. Also it says something about injectors on the exhaust side??? Translation errors or something else?
I read it to mean Honda went from original pneumatic valve return to conventional coil springs to eliminate the pneumatic system weight. It says each coil spring is actually a triple-spring combo, which typically prevents any one spring resonance from dominating and provides light friction damping between springs. Current materials and dynamic modeling make conventional springs possible at revs where pneumatic used to be needed.

Would be interesting to know if other engines (Merc., Ferrari, Renault) use coil springs instead of pneumatic, and would be interesting to know if Honda sticks with coil-spring for the higher revs in 2021.
Going back to coil springs over Pneumatic is a very odd thing to do and I find it very very srprising. Even at "only" 13,000 rpm the valvetrain dynamics are very hard to control when using aggressive ramps. Jerk is not your friend.
Not to mention the difference in weight between the valve springs themselves and the entire Pneumatic system is not as great as one might think.

Nonserviam85
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Re: Honda Power Unit

Post by Nonserviam85 » Fri Jan 12, 2018 4:04 pm

hurril wrote:
Fri Jan 12, 2018 8:15 am
ncassi22 wrote:
Fri Jan 12, 2018 7:22 am
The article mentions the Pneumatic valve system. It dindn't make clear whether the system was reduced in components/simplified to save weight or dumped for a springvalve system. Also it says something about injectors on the exhaust side??? Translation errors or something else?
It does mention using a spring-valve system instead.
:shock: :shock:

ncassi22
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Joined: Sat Apr 27, 2013 1:26 am

Re: Honda Power Unit

Post by ncassi22 » Fri Jan 12, 2018 4:55 pm

MrPotatoHead wrote:
Fri Jan 12, 2018 3:46 pm
bill shoe wrote:
Fri Jan 12, 2018 3:23 pm
ncassi22 wrote:
Fri Jan 12, 2018 7:22 am
The article mentions the Pneumatic valve system. It dindn't make clear whether the system was reduced in components/simplified to save weight or dumped for a springvalve system. Also it says something about injectors on the exhaust side??? Translation errors or something else?
I read it to mean Honda went from original pneumatic valve return to conventional coil springs to eliminate the pneumatic system weight. It says each coil spring is actually a triple-spring combo, which typically prevents any one spring resonance from dominating and provides light friction damping between springs. Current materials and dynamic modeling make conventional springs possible at revs where pneumatic used to be needed.

Would be interesting to know if other engines (Merc., Ferrari, Renault) use coil springs instead of pneumatic, and would be interesting to know if Honda sticks with coil-spring for the higher revs in 2021.
Going back to coil springs over Pneumatic is a very odd thing to do and I find it very very srprising. Even at "only" 13,000 rpm the valvetrain dynamics are very hard to control when using aggressive ramps. Jerk is not your friend.
Not to mention the difference in weight between the valve springs themselves and the entire Pneumatic system is not as great as one might think.
Yeah my thoughts too? Could this be part of the friction issue Brown and then Wazari alluded to. I hope he can share his thoughts on this.

amho
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Re: Honda Power Unit

Post by amho » Fri Jan 12, 2018 8:23 pm

hurril wrote:
Fri Jan 12, 2018 8:15 am
ncassi22 wrote:
Fri Jan 12, 2018 7:22 am
Also it says something about injectors on the exhaust side??? Translation errors or something else?

Injectors on the exhaust side is nothing strange. The injector merely sits on the cylinderbank together with the exhaust valves instead of with the intake valves.
I always thought that the injector is placed in the top of prechamber, but If injector is in exhaust side (as motor fan pic. indicates) how do they have rich mixture in the prechamber? there might be multiple injection first one when piston is near tdc to mainly fill prechamber?
https://drive.google.com/open?id=1tpCUl ... SY3ZJV5gNa
There is no Might or Power except with Allah.

roon
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Re: Honda Power Unit

Post by roon » Fri Jan 12, 2018 8:35 pm

Maybe stacked belleville springs instead of coil, to mimic the symmetrical loading offered by pneumatics.

Mudflap
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Re: Honda Power Unit

Post by Mudflap » Fri Jan 12, 2018 9:55 pm

Multiple valve springs with friction damping makes no sense whatsoever.
Renault have PVRS - Hulky I think retired due to loss of pneumtic pressure.
Mercedes have PVRS on the hypercar - surely they have it on the F1 engine too.

Other than the actual seal diaphragm and the pneumatic barrels they only need a pressure vessel with a regulator and a few hoses.
How much TQ does it make though?

bill shoe
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Re: Honda Power Unit

Post by bill shoe » Fri Jan 12, 2018 10:28 pm

Google "triple valve springs", then go to images. It's the standard high performance valvespring config. I think the middle spring is often there to provide control and light damping to the inner and outer springs that do most of the heavy lifting.
Image

Wazari
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Re: Honda Power Unit

Post by Wazari » Fri Jan 12, 2018 10:57 pm

Today's valves springs can handle 13,000 PRM with no problem.
If you can make the opposition flinch, you have already won.

godlameroso
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Re: Honda Power Unit

Post by godlameroso » Fri Jan 12, 2018 11:50 pm

I mean Honda made single coil springs that could handle 9,100 rpm and 400,000km of service back in 1999. I would not be surprised if they had valve springs capable of handling 13k for 7,000km 19 years later.
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

ncassi22
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Re: Honda Power Unit

Post by ncassi22 » Sat Jan 13, 2018 1:39 am

godlameroso wrote:
Fri Jan 12, 2018 11:50 pm
I mean Honda made single coil springs that could handle 9,100 rpm and 400,000km of service back in 1999. I would not be surprised if they had valve springs capable of handling 13k for 7,000km 19 years later.
In terms of reliability yes, however I was thinking in terms reducing friction... wouldn't every hp they could squeeze out be helpful. The snowball effect of which has been discussed here. My (admittedly non-enigneer) brain would think the close to 5 bar boost would require some heavy duty springs?

*edit - did some reading. Seems boost doesn't have much of an effect.
Last edited by ncassi22 on Sat Jan 13, 2018 2:03 am, edited 1 time in total.

godlameroso
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Re: Honda Power Unit

Post by godlameroso » Sat Jan 13, 2018 2:01 am

Believe it or not engine speed puts much more stress on the rotating assembly than cylinder pressure.

The part that really amazes me is that the top piston ring is under far more stress than the valves/springs, and a cylinder ring is thin, and relatively brittle, you can break it with your hands by bending it aggressively.
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

PlatinumZealot
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Re: Honda Power Unit

Post by PlatinumZealot » Sat Jan 13, 2018 2:04 am

ncassi22 wrote:
Sat Jan 13, 2018 1:39 am
godlameroso wrote:
Fri Jan 12, 2018 11:50 pm
I mean Honda made single coil springs that could handle 9,100 rpm and 400,000km of service back in 1999. I would not be surprised if they had valve springs capable of handling 13k for 7,000km 19 years later.
In terms of reliability yes, however I was thinking in terms reducing friction... wouldn't every hp they could squeeze out be helpful. The snowball effect of which has been discussed here. My (admittedly non-enigneer) brain would think the close to 5 bar boost would require some heavy duty springs?
I dont see how friction to turn the cam would change much versus pneumatic if the springs are designed properly. Pneumatic is also addtional complexity and space taken up.