2021 Engine thread

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
trinidefender
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Re: 2021 Engine thread

Post by trinidefender » Mon Jul 22, 2019 7:10 pm

MAHLE has stated that they have developed a version with only one injector outside of the prechamber.
Two versions of the MJI system have been developed:
Active MJI featuring a spark plug and micro- ow fuel injector within the pre-chamber
Passive MJI which only contains a spark-plug
Passive MJI
1 fuel injector utilised:
• 1 Injector (DI or PFI) for delivering the main charge
• No injector required in the pre-chamber
(fuelling carried over from main chamber)
https://www.mahle-powertrain.com/media/ ... mation.pdf

roon
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Re: 2021 Engine thread

Post by roon » Mon Jul 22, 2019 8:51 pm

That pdf says it is even compatible with port injection only. I'm not sure how they would accomplish mix stratification near the bulb in such an arrangement. Presumably the jets can adequately form regardless of prechamber richness, as though the flow restriction of the prechamber holes alone are enough.

gruntguru wrote:
Mon Jul 22, 2019 4:56 am
Think of a cloud of air-fuel mix...
Good explanation. Thank you.

gruntguru
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Joined: Sat Feb 21, 2009 6:43 am

Re: 2021 Engine thread

Post by gruntguru » Tue Jul 23, 2019 12:25 am

roon wrote:
Mon Jul 22, 2019 8:51 pm
That pdf says it is even compatible with port injection only. I'm not sure how they would accomplish mix stratification near the bulb in such an arrangement.
The single injector MJI system is not lean burn - it is lambda 1.0. The advantages of the system are rapid combustion, ability to run lambda 1.0 at full load (road car engines typically run 0.9 or richer), and reliable ignition of highly diluted (EGR) mixtures.

The Formula 1 single injector MJI is a lean burn version. It requires direct injection, high injection rates and complex injection strategies and mapping.
je suis charlie

roon
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Re: 2021 Engine thread

Post by roon » Wed Jul 24, 2019 5:52 am

gruntguru wrote:
Tue Jul 23, 2019 12:25 am
roon wrote:
Mon Jul 22, 2019 8:51 pm
That pdf says it is even compatible with port injection only. I'm not sure how they would accomplish mix stratification near the bulb in such an arrangement.
The single injector MJI system is not lean burn - it is lambda 1.0. The advantages of the system are rapid combustion, ability to run lambda 1.0 at full load (road car engines typically run 0.9 or richer), and reliable ignition of highly diluted (EGR) mixtures.

The Formula 1 single injector MJI is a lean burn version. It requires direct injection, high injection rates and complex injection strategies and mapping.
Thank you. I was under the impression that a relatively rich mixture, relative to CC AFR, was needed inside the prechamber to create these jets. Seemingly not. Anyway, lean burn and stratification would not be mutually exclusive would they? As AFR and lambda only refer to charge composition and stratification refers only to distribution. Could have one large droplet of fuel providing lambda 1 or less, at stratification greater than a highly leaned F1 engine.

dren
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Joined: Wed Mar 03, 2010 1:14 pm

Re: 2021 Engine thread

Post by dren » Wed Aug 07, 2019 1:47 pm

ENGINE TUNER wrote:
Thu Jul 18, 2019 12:51 pm
Pyrone89 wrote:
Thu Jul 18, 2019 12:34 pm
Braking does for the K
Braking only provides about 20% of the power that the K currently puts out, where are you going to get the rest of the 80% that the H currently provides?
Electric fuel accumulation via ICE overrun with K generating. It's what teams did during the KERS years and what they are likely doing now at certain points. We know Honda does it, or at least did it, in 2017.
Honda!

roon
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Re: 2021 Engine thread

Post by roon » Thu Aug 08, 2019 5:30 am