F1technical.net

Best to build chassis around engine, then shrink wrap the chassis around the engine through development. So once a foundation is established you tighten up the chassis, and when the engine department makes gains in cooling packaging, the chassis department is ready with bodywork to take advantage of the engine gains.

techman wrote: ↑

05 Mar 2018, 15:12

Which one is easier, engine follow chassis OR chassis follow engine

i think honda have learnt their lesson. it should always be build a chassis around the engine.

Given the lack of power, and success Ferrari had in 2014 after they made the same mistake of building a space-starved PU and couldn't compensate with the aero, that does seem the case; it also seems like it needed to be tried/learned the hard way, both by McLaren and Honda, instead of looking at where Ferrari went wrong (okay, maybe too late by then already to turn around, during 2014, but still seems very blue-eyed going in from Honda).

HPD, that interview is very impressive, and does give hope that Honda have turned a corner now, understand where they went wrong and know how to move forward.

HPD wrote: ↑

05 Mar 2018, 13:35

Honda RA61$H

*cut*

All credits to @FCIUS
https://www.reddit.com/r/formula1/comme ... h=d3ef5235

"Ideally this was something we must have completed before the season started. But Mclaren wasn't willing to wait that long." says Kakuta with some regret. However. a breakthrough is in sight for 2018.

Does that mean the new combustion method isn't ready yet or will it be ready at the start of this season? Or is the "breakthrough" pointing at something else?

Thanks for the story

@Mr. Potato Head, I did not take your post as criticism. I just wanted to point out that IMO HRD is very "un-Japanese" when compared to most Japanese corporations.

I am surprised at how transparent and detailed the above article is. I did not expect Honda to allow Kakuta-san to be so open. I am not surprised how very politically polite the article was. I think it sums up from a 10,000 meter view of what happened and I agree with 99% of what is written.

Definitely easier to design a chassis around a PU then the other way around.

@PZ, I assume all your questions were answered in that article?

Breakthrough I believe refers to new combustion hardware/process. My understanding not ready yet...but will be mid-season. Come on 740 kW....please.............

PlatinumZealot wrote: ↑

05 Mar 2018, 06:35

Looks like the engine oil is different from the MGUH oil (obviously right?). And it seems the compressor sucked up the oil from the bad version 1 oil tank then somehow blowed engine oil into the MGUH bearings?! Can anyone explain how the compressor volute is connected to the MGUH bearings?

Pages 4 and 5.
https://abload.de/img/untitled4v4s2w.png
https://abload.de/img/untitled5t4s7t.png

Snorked wrote: ↑

05 Mar 2018, 03:19

Reddit user FCIUS is translating the article:

http://abload.de/img/untitled1wtjtw.png
https://abload.de/img/untitled2cjpnn.png
https://abload.de/img/untitled3zoso3.png

I'll do the rest once I eat dinner - please ignore any grammatical issues, as I didn't proofread the text.

Also sorry for the sloppy photoshopping.

https://www.reddit.com/r/formula1/comme ... h=d3ef5235

I don't think it is a separate lubrication system with different oil - the issue seemed to be that the bearings were improperly scavenged and flooded. Every single piece of automotive and aero turbomachinery I have ever seen had ring type seals which have a bit of a gap by design. Normally the higher pressure on the compressor and turbine side stops them from leaking - even more so when the bearing cavities are scavenged and their pressure is slightly lower than ambient.
My interpretation of the 'oil blowing' mentioned a while ago was that oil made its way into the scavenging air lines which normally pull from the top of the oil tank. This would result in a large vacuum in the bearing cavities preventing oil outflow.

I think Wazari stated that MGUH bearings failed due to oil starvation caused by pump cavitation, this article seems claim the contrary - too much oil the bearings. Since inadequate oil pump flow would alway fail crank mains or big end bearings first (generally the hydrodynamic bearings which require high flow rates compared to rolling element bearings) I tend to go with what the article says.

johnny comelately wrote: ↑

05 Mar 2018, 04:37

i posted this in the general honda thread, so i suppose it should be in here:
They are allowed about 29 grams of fuel per second maximum (rate) and the power figure of 950hp, can someone calculate the energy content of the fuel ?

Works out at just over 51MJ/kg at 50% TE. Not too far off 44MJ/kg or so for pump fuel.

Cavitation in the oil tank caused the problem. To stop oil starvation the tank was intentionally overfilled. This led to problems in several areas including bearings.

Wazari wrote: ↑

05 Mar 2018, 22:15

Breakthrough I believe refers to new combustion hardware/process. My understanding not ready yet...but will be mid-season. Come on 740 kW....please.............

740 kW !!! Thats a hugee leap in power. But how can you be so confident of the output if it has not been run on the dynos? Guess the testing in Hungary will be perfect time to launch this engine.

Also Honda have said they now have magic qual modes, is this with extra stuff or just running engine at full pelt?

Wazari wrote: ↑

05 Mar 2018, 22:54

Cavitation in the oil tank caused the problem. To stop oil starvation the tank was intentionally overfilled. This led to problems in several areas including bearings.

Sure, if the oil level increases it is more likely for oil to get sucked into the scavenge lines. However your post on page 852 states that the issue was air into the the MGUH feed due to cavitation. So what killed the bearings - cavitation or overfilling?

I'm being hopeful, not confident that 740 can be reached. It is being dyno'd. Qualifying mode is not magic. I understand that a full qualifying mode map has been tested and successful, mainly to do with ERS storage and deployment.

The MGU-H issue was a domino like effect. It wasn't as simple as a bearing lubrication issue. Oversimplying the shaft bearing connecting the compressor to the MGU-H had issues with lubrication and temps due to starvation, the "sealed" H bearings because of unexpected temps had an issue with oil-wash after starvation was patch remedied.

I find that jet ignition with prechamber fuel injection was patented in 1975!
https://patents.google.com/patent/US3983847

The patent mentions spraying the fuel onto the spark plug, which plays a role in breaking up the fuel flow.

But don't the unique exhaust smell of the mercedes and the penchant for burning oil still suggest there is an element of compression ignition going on???

What is oil wash and what do you mean by sealed bearings ?

blueytoo wrote: ↑

05 Mar 2018, 23:55

I find that jet ignition with prechamber fuel injection was patented in 1975!
https://patents.google.com/patent/US3983847

The patent mentions spraying the fuel onto the spark plug, which plays a role in breaking up the fuel flow.

Honda CVCC was developed in the late 1960s. Same basic concept. Mahle TJI is a significant step forward from those days. Much smaller pre-chamber volume, higher velocity jets, configured as an add-on to work with existing pent-roof combustion chamber designs.

Mudflap wrote: ↑

05 Mar 2018, 23:56

What is oil wash and what do you mean by sealed bearings ?

I've the same question to Wazari. Perhaps the related bearings should have to work in a dry environnement. Then when the oil tank was overfitted it spreads some oil to theses critical parts running at high velocity.
So cavitation appears in this unexpected amount of oil in these heavy conditions, and finally it contributes to destroy the devices.

Wazari wrote: ↑

05 Mar 2018, 22:54

Cavitation in the oil tank caused the problem. To stop oil starvation the tank was intentionally overfilled. This led to problems in several areas including bearings.

So Wazari, can you confirm that the MGUH shares oil with the engine? (Mudflap I only just saw your comment!) but just for due diligence.

From what I know of oil wash it is when one oil contaminates and washes off another oil from a bearing surface?