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Re: Honda Power Unit
Posted: 23 Jan 2018, 01:37
by ringo
roon wrote: ↑22 Jan 2018, 20:10
godlameroso wrote: ↑22 Jan 2018, 19:59
Notice they have one camshaft that has a lobe for both the intake and exhaust valve...
Good catch. Pair the runners fore-to-aft, rather than side-to-side, and stack them vertically instead of horizontally. Might explain the 'taller' head reference.
What would be the benefit of having one exhaust valve in the shadow of the other during the exhaust stroke?
Doesn't seem very intuitive.
I can imagine maybe the exhaust port is shared by both valves and can have an expanding port size towards the flange of the exhaust pipes?
Re: Honda Power Unit
Posted: 23 Jan 2018, 04:05
by godlameroso
Cross flow promoting swirl?
Re: Honda Power Unit
Posted: 23 Jan 2018, 12:25
by Tommy Cookers
two race engines built in the 60s that fit the description ......
the Apfelbeck F2 BMW engine and the Type 50 Repco-Brabham head had EV-IV-EV-IV not the usual
the BMW was radial (2 plane inclination) the Type 50 was pent roof (1 plane inclination)
Re: Honda Power Unit
Posted: 23 Jan 2018, 14:00
by dren
roon wrote: ↑22 Jan 2018, 23:40
If each runner (per-cylinder) is individually throttled as part of a VIM system, then you could indeed effectively have variable flow properties without variable valve timing. Call it variable flow timing. One valve can actuate earlier than another via asymmetrical cam lobe phasing. The throttles would be used preference flow into one runner or the other, which in turn determines when the bulk of the intake flow enters the cylinder.
To eliminate flow restriction trade-offs, you oversize the runners. Which might explain a taller head.
I'm sure this would help with the homogeneous mixing to fill the pre-chamber.
Re: Honda Power Unit
Posted: 23 Jan 2018, 15:25
by ncassi22
Wazari wrote: ↑22 Jan 2018, 22:24
Yes I meant the "boxer" engine camshafts. Some of you are spot on on your assumptions.
I hear that dyno testing is going well in terms of reliability and efficiency. After accomplishing those targets comes power. The baseline for the 618 is done and running. They are many more innovations in the pipeline which I highly doubt the other manufacturers will have in 2018 or ever for that matter, that Honda will try and fully incorporate by mid-season.
I would like to see the fuel flow limit go away and allow refueling during a race. This is racing....????
Any indication (that you can share) as to how the baseline engine compares to the end of season 617?
Re: Honda Power Unit
Posted: 25 Jan 2018, 03:31
by godlameroso
Random thought, unusual ports maybe give you more leeway regarding the location of the valves themselves.
Also, my own curiosity, how would one reduce friction in the rocker arms? I doubt there's a better solution than one Honda already made.
Re: Honda Power Unit
Posted: 26 Jan 2018, 02:40
by GhostF1
Wazari wrote: ↑22 Jan 2018, 22:24
Yes I meant the "boxer" engine camshafts. Some of you are spot on on your assumptions.
I hear that dyno testing is going well in terms of reliability and efficiency. After accomplishing those targets comes power. The baseline for the 618 is done and running.
They are many more innovations in the pipeline which I highly doubt the other manufacturers will have in 2018 or ever for that matter, that Honda will try and fully incorporate by mid-season.
I would like to see the fuel flow limit go away and allow refueling during a race. This is racing....????
This quote fascinates me. That's a super confident claim, especially while they are still trying to reach a strong baseline, but I never underestimate the Japanese, especially a company as large as this with as much pressure that's in been faced with. I'm hoping for an enormous reaction! I'm very excited to see what Honda pulls out of the hat this year
.
Re: Honda Power Unit
Posted: 26 Jan 2018, 11:35
by Postmoe
GhostF1 wrote: ↑26 Jan 2018, 02:40
Wazari wrote: ↑22 Jan 2018, 22:24
Yes I meant the "boxer" engine camshafts. Some of you are spot on on your assumptions.
I hear that dyno testing is going well in terms of reliability and efficiency. After accomplishing those targets comes power. The baseline for the 618 is done and running.
They are many more innovations in the pipeline which I highly doubt the other manufacturers will have in 2018 or ever for that matter, that Honda will try and fully incorporate by mid-season.
I would like to see the fuel flow limit go away and allow refueling during a race. This is racing....????
This quote fascinates me. That's a super confident claim, especially while they are still trying to reach a strong baseline, but I never underestimate the Japanese, especially a company as large as this with as much pressure that's in been faced with. I'm hoping for an enormous reaction! I'm very excited to see what Honda pulls out of the hat this year
.
I had initially understood this as a very pesimistic statement.
Now I see that, if adding a patina of pride, it becomes something quite different. I hope Honda is able to deliver that way. I would be very good news.
Re: Honda Power Unit
Posted: 26 Jan 2018, 12:13
by Wouter
Wazari wrote: ↑22 Jan 2018, 22:24
I hear that dyno testing is going well in terms of reliability and efficiency. After accomplishing those targets comes power. The baseline for the 618 is done and running. They are many more innovations in the pipeline which I highly doubt the other manufacturers will have in 2018 or ever for that matter, that Honda will try and fully incorporate by mid-season.
That seems to me very good news Wazari, thanks.
Do you also know the difference between the reliability and the power between the Abu Dhabi race and this moment?
At least what the test results say?
Re: Honda Power Unit
Posted: 26 Jan 2018, 13:31
by etusch
In that statement I think there is power too. if efficiency improved...
Re: Honda Power Unit
Posted: 26 Jan 2018, 14:17
by dren
etusch wrote: ↑26 Jan 2018, 13:31
In that statement I think there is power too. if efficiency improved...
Or efficiency improved, but power stayed level, so fueling for the race can be decreased which improves lap times. Mercedes caries significantly less fuel than the other three.
Re: Honda Power Unit
Posted: 26 Jan 2018, 16:43
by godlameroso
Efficiency = power. It means achieving the same with less, so if you use the same you achieve more(over a fixed number of laps)
Power is a function of force over time.
Re: Honda Power Unit
Posted: 26 Jan 2018, 16:46
by etusch
And if you have better reliability you can use higher power without fear
Re: Honda Power Unit
Posted: 26 Jan 2018, 17:12
by hurril
godlameroso wrote: ↑26 Jan 2018, 16:43
Efficiency = power. It means achieving the same with less, so if you use the same you achieve more(over a fixed number of laps)
Power is a function of force over time.
Well, not really. Peak power comes as a function of efficiency of the PU which I know that you know of course. I don't think repeating that is particularly conducive to understanding what's going on here though. Reducing losses in the ERS won't show on a peak power graph but will cut the lap times.
Re: Honda Power Unit
Posted: 26 Jan 2018, 17:13
by dren
godlameroso wrote: ↑26 Jan 2018, 16:43
Power is a function of force over time.
Work over time, maybe...