2021 Engine thread

[henry]

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Larger SOC, so they can save up a few laps of energy, than deploy in a single lap.

You’d need to increase the ES -> K limit as well as the SOC. they already do what you suggest. E.g. Ricciardo chasing Verstappen at Baku.

I think that removing the MGU-H would need a completely new system to manage boost and lag. Chances are they’d design a completely new ICE to optimise that.

And I should have been clear that the 1MJ K recovery was from braking.

[NL_Fer]

Yeah, 1.6 V6 Turbo-MGU-H is here to stay, i doubt we will see higher revs or bigger flow limits in ‘21. ERS energy limits and deployment method is the only variable to be changed without much engine redesign.

[roon]

Huge amounts of money dumped into this engine formula. Now they are stuck with it as an investment. Six years and still no road car applications. What would those have been anyway? These engines produce high nox emmissions, same compound VW got in trouble over during dieselgate.

Expensive non road relevant powertrains, arguably not even track relevant. RB tried to alter the course. Had they succeeded Porsche may have entered as an engine supplier. RB were the main source of reason since they are the largest force not chained financially to the existing engine formula. Their workaround was getting Honda. But Honda are no Merc.

[Dr. Acula]

Huge amounts of money dumped into this engine formula. Now they are stuck with it as an investment. Six years and still no road car applications. What would those have been anyway? These engines produce high nox emmissions, same compound VW got in trouble over during dieselgate.

Expensive non road relevant powertrains, arguably not even track relevant. RB tried to alter the course. Had they succeeded Porsche may have entered as an engine supplier. RB were the main source of reason since they are the largest force not chained financially to the existing engine formula. Their workaround was getting Honda. But Honda are no Merc.

Well, were F1 powertrains ever relevant for road cars?
These are purpose build engines meant for a very specific task, they always were. Even the infamous BMW M12 had in reality very little in common with the engine you found in any road legal BMW at the time.

[Jolle]

Huge amounts of money dumped into this engine formula. Now they are stuck with it as an investment. Six years and still no road car applications. What would those have been anyway? These engines produce high nox emmissions, same compound VW got in trouble over during dieselgate.

Expensive non road relevant powertrains, arguably not even track relevant. RB tried to alter the course. Had they succeeded Porsche may have entered as an engine supplier. RB were the main source of reason since they are the largest force not chained financially to the existing engine formula. Their workaround was getting Honda. But Honda are no Merc.

Well, were F1 powertrains ever relevant for road cars?
These are purpose build engines meant for a very specific task, they always were. Even the infamous BMW M12 had in reality very little in common with the engine you found in any road legal BMW at the time.

Most things tricking down from formula one into normal vehicles are not that visible. What Mahle does for instance, their jet-ignition for extreme lean burn is something that they developed for F1 to sell to the general car manufacturers.

[roon]

I dont think TJI has been used in F1. Photos of the power units show a traditionally located spark plug and fuel injectors entering on the the exhaust side of the combustion chamber, with the fuel rail running along the sides of the engine beneath the exhaust manifolds. TJI requires the spark plug and injector to be installed side by side, in order to share a small prechamber.

It should be easy to identify fuel rails, fuel lines, or injectors on the topside of the cam covers, which TJI would need, but this has never been shown in photos. Only spark plugs and pressure sensors are ever seen in this area.

[trinidefender]

I dont think TJI has been used in F1. Photos of the power units show a traditionally located spark plug and fuel injectors entering on the the exhaust side of the combustion chamber, with the fuel rail running along the sides of the engine beneath the exhaust manifolds. TJI requires the spark plug and injector to be installed side by side, in order to share a small prechamber.

It should be easy to identify fuel rails, fuel lines, or injectors on the topside of the cam covers, which TJI would need, but this has never been shown in photos. Only spark plugs and pressure sensors are ever seen in this area.

It was stated by MAHLE in a press release that a variation of their technology is used in F1 by Ferrari. It was also confirmed in an article of an interview of a Honda engineer that they also use prechamber technology.

The difference between the TJI as we conventionally know it shown in the MAHLE papers and what would be used in F1 is the number and placement of injectors. The conventional way uses 2 injectors. 1 in the prechamber, 1 outside. F1 PU's are limited to just 1 injector. The injector is placed outside with a small amount of fuel being sprayed at the prechamber nozzles charging the prechamber. The spark plugs are in the prechamber. This is the most likely configuration.

[roon]

The injector is placed outside with a small amount of fuel being sprayed at the prechamber nozzles charging the prechamber. The spark plugs are in the prechamber. This is the most likely configuration.

Shooting fuel ~40mm across the combustion chamber toward a bulb with microscopic holes drilled into it, holes sized for the creation of tuned gas/plasma jets and not for conveying liquids, and expecting the right amount of fuel to reliable go through those tiny holes to collect inside the bulb, seems unlikely.

I should add that my last post about fuel rails applies to Merc but not necessarily Ferrari.

Below is an image of the Ferrari 2014(?) power unit. Clealy visible are three rigid hydraulic lines running down the center of the cam cover. If they are not for oil or coolant, they could very well be fuel lines. They look more like high pressure fuel lines. Right next to them are spark plug wires. If so there is the as-published TJI system. Which make me wonder why we ever considered the whole 'shoot the fuel in from the outside' concept here on the forum.

[gruntguru]

The injector is placed outside with a small amount of fuel being sprayed at the prechamber nozzles charging the prechamber. The spark plugs are in the prechamber. This is the most likely configuration.

Shooting fuel ~40mm across the combustion chamber toward a bulb with microscopic holes drilled into it, holes sized for the creation of tuned gas/plasma jets and not for conveying liquids, and expecting the right amount of fuel to reliable go through those tiny holes to collect inside the bulb, seems unlikely.

The way this could be done has been discussed in detail in one of these threads. Didn't you read that? It seems feasible to me. We are not talking about shooting droplets into small pre-chamber holes.

Think of a cloud of air-fuel mix. Lean at the start of the compression stroke - this is the main-chamber charge. This lean mix is also what enters the pre-chamber during compression. At some later stage of compression the injector fires again to position a rich mixture zone near the pre-chamber. As compression continues, some of this richer mixture enters the pre-chamber to create a mixture somewhere between 0.9 and 1.0 lambda. This can be highly customised on the dyno by juggling the duration and timing of each of multiple injection pulses. All these variables would have to be optimised at every load speed combination on the dyno. Lots of dyno time!!!!

[gruntguru]

These engines produce high nox emmissions, same compound VW got in trouble over during dieselgate.

Do you have a source for that information? If correct, it would be due to the combination of high compression and high boost. That could be easily solved on a road car by reducing compression without much efficiency loss.

[roon]

If that is being done, is it to get around the Mahle patent? Or a geometrical constraint within the cylinder head? Seems easier to position the injector and SP together in the prechamber. The photo I just posted suggests Ferrari might have done this. If they are in contract with Mahle it could limit use depending how their patent is worded.

Re: NOx, that was my understanding of diesels, high temp/compression combustion modes.

[henry]

For those who haven’t seen it here’s a diagram of the Honda pre-chamber implementation.



It comes from this post, viewtopic.php?p=733944#p733944, which is one of the most useful on the forum. With careful reading it reveals lots about the design and operation of these PUs.

[saviour stivala]

Mahle’s TJI is not compatible with the F1 direct injection rules as it not only injects the fuel inside a pre-combustion chamber but also starts combustion inside said combustion chamber.

[Dr. Acula]

If that is being done, is it to get around the Mahle patent? Or a geometrical constraint within the cylinder head? Seems easier to position the injector and SP together in the prechamber. The photo I just posted suggests Ferrari might have done this. If they are in contract with Mahle it could limit use depending how their patent is worded.

Re: NOx, that was my understanding of diesels, high temp/compression combustion modes.

No, it's done because the rules say that they can only use one injector per cylinder. For road car use it would probably be the best solution to use TJI with one injector for the prechamber and a port injector. This way they can prevent the problems the Mercedes Project One run into which produced to much particulate matter.

Regarding NOx. From a standpoint of simply creating NOx, this problem isn't Diesel exclusive. Gasoline engines produce also NOx emmisions, although a bit less relative to the amount of fuel burnt. The mayor difference though is the exhaust after treatment. Where in a normal Gasoline engine the Catalytic converter converts NOx, CO and unburnt hydrocarbons basically in a single stage, it's a lot more complicated with Diesel exhaustgases to get them clean.

[trinidefender]

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