2026 Drama: Alleged engine loophole

[upsidedowntoast]

For what it's worth, I hated the Mercedes 2014-2021 years because they were so boring,

2021 boring???

That was one of the most exciting seasons in a long time!!!

My bad, 2014-2020.

[FrukostScones]

For what it's worth, I hated the Mercedes 2014-2021 years because they were so boring,

2021 boring???

That was one of the most exciting seasons in a long time!!!

My bad, 2014-2020.

2016, 2017, 2018 were fun.

[fourmula1]

The rule wording change just seems like optics to me. They weren't allowed to go above 16:1 before with or without the use of components/parts/designs.

[bluechris]

2021 boring???

That was one of the most exciting seasons in a long time!!!

My bad, 2014-2020.

2016, 2017, 2018 were fun.

For whom except MB followers?

[Badger]

Not sure about that at all.

There may be small parts of the engine that are above 130degC consistently but the average temperature throughout the entirety of the block, cylinder, piston, rod etc. would be around there. Thermal expansion is a function of the average temperature across the entire length of the material, not the highest temperature measured in one spot. The main contributing factor to increased CR when the engine is hot would be expansion in the rod, but the rod is entirely isolated from combustion behind the piston and would likely not see temperatures above 130degC at any stage.

I think that if a manufacturer intended to exploit thermal expansion, they would make sure the rod gets very hot (but not so hot to compromise the stiffness or bearing friction). So static heating to 130C may not reveal much.

That's also if we assume this is about rod stretch and not secondary chambers. In my opinion, the explicitness of the amendment closes the loophole firmly, test or not. Large auto manufacturers are boring. Mercedes is not going to break the rules after June 1st. They do gray areas, not rule breaking.

Sounds like fantasy to me, the idea of super-heating the rod. That would mean your oil is well above 130degC too. That engine would blow.

The useful temperature delta is between ambient and 130C, anything above that is just going to jeopardize the integrity of the engine. So with the test at 130degC it should put an end to almost all possible trickery with thermal expansion. The stuff around a second chamber I never bought into.

[Badger]

The test is not the major change to the regulations. Engine operating temperature is greater than 130C so that is just for show. This is the most important addition to the regulations:



Anyone who thinks Mercedez-Benz will just outright cheat after Jun 1st, doesn't understand how large auto manufacturers think.

Not sure about that at all.

There may be small parts of the engine that are above 130degC consistently but the average temperature throughout the entirety of the block, cylinder, piston, rod etc. would be around there. Thermal expansion is a function of the average temperature across the entire length of the material, not the highest temperature measured in one spot. The main contributing factor to increased CR when the engine is hot would be expansion in the rod, but the rod is entirely isolated from combustion behind the piston and would likely not see temperatures above 130degC at any stage.

You'll need more research in that case. 130C maybe more typical for coolant and oil etc, piston crown could be 200C ~450C as a example.
The surfaces are partly insulated from true combustion peak temperatures by boundary layer dynamics, which if knock occurs will break down to overheat the materials. Ultimately why control of and preventing knock is so important part of combustion control.

I explicitly said small parts of the engine may be above that temperature consistently. However, thermal expansion is a function of the average temperature across the entire length of material in whatever direction you're measuring the expansion. The crown is very thin and thus limited in its expansion capability even if very hot. It would not be unreasonable at all to think that the average temperature from the top of the crown to the bottom of the rod (during operation) would be around 130degC. And even if it were marginally higher than that the change to the test would catch the vast majority of all possible expansion.

[f1isgood]

The wording is interesting. Mercedes might still be able to use their tricks to run the engine at 16:1 from June onwards. The rule only says you cant use tricks to beat 16:1 at operation, not that you cannot use tricks to get there. Since right now everyone else is at supposedly 15.2 or 15.3 or whatever, they're stuck with that till the end of the year unlike Mercedes who can rehomologate to still maintain an advantage to comply with the rules...

This year is going to be a McLaren versus Mercedes fight for the title with Ferrari in between.

[venkyhere]

Noob Q : the CAD drawings can be used to calculate geometric compression ratio. What 'temperature' is the CAD drawing meant for ? I think the questions should start from there. Whether the compression ratio increases/decreases from ambient to operating temp, is going to be answered by the "CAD drawing temperature" question.
I am sure all teams know that operating temp geometries are going to be different from ambient numbers, so there can be teams who started with a conservative/aggressive CAD drawing CR number, and then 'expect' the operating CR number to comply with the rules.
Q is, is Mercedes excedding 16:1 in both cases (CAD file & operating temp number) ? If yes, it's cheating, because there is no way to wriggle away with 'oh but we thought this was the temp the rule was meant for' excuse.
And if indeed that's the case, are they being allowed to get away with it until June and build up a 'points lead' ? Is this deja-vu of "Toto-the-political-snake" in action ?

[AR3-GP]

Since right now everyone else is at supposedly 15.2 or 15.3

I doubt this.

[f1isgood]

Since right now everyone else is at supposedly 15.2 or 15.3

I doubt this.

If compression ratio decreases usually I dont see why this isnt the case. Didn't you give a good explanation yourself that this can happen simply based on thermal expansion when I asked for a clarification on dropping from 16 to 15.2 being more than 5%?

Of course it could be the case that the engine manufacturers have better material scientists at the end of the day that doesnt allow such a drop but I would be surprised if it didnt... there's no reason to create a huge story otherwise (imo).

[f1isgood]

Noob Q : the CAD drawings can be used to calculate geometric compression ratio. What 'temperature' is the CAD drawing meant for ? I think the questions should start from there. Whether the compression ratio increases/decreases from ambient to operating temp, is going to be answered by the "CAD drawing temperature" question.
I am sure all teams know that operating temp geometries are going to be different from ambient numbers, so there can be teams who started with a conservative/aggressive CAD drawing CR number, and then 'expect' the operating CR number to comply with the rules.
Q is, is Mercedes excedding 16:1 in both cases (CAD file & operating temp number) ? If yes, it's cheating, because there is no way to wriggle away with 'oh but we thought this was the temp the rule was meant for' excuse.
And if indeed that's the case, are they being allowed to get away with it until June and build up a 'points lead' ? Is this deja-vu of "Toto-the-political-snake" in action ?

Toto has locked in a Merc advantage. Their trick is valid for this year. From next year they have one year's worth lead time to take their trick even further while others will catch up. Unlike aero, you cant even copy these things lol. This regulations will be fought between Woking and Brackley.

[AR3-GP]

Since right now everyone else is at supposedly 15.2 or 15.3

I doubt this.

If compression ratio decreases usually I dont see why this isnt the case. Didn't you give a good explanation yourself that this can happen simply based on thermal expansion when I asked for a clarification on dropping from 16 to 15.2 being more than 5%?

Of course it could be the case that the engine manufacturers have better material scientists at the end of the day that doesnt allow such a drop but I would be surprised if it didnt... there's no reason to create a huge story otherwise (imo).

It's likely that the other manufacturers have done work specifically to maintain a 16:1 compression ratio where it otherwise normally drop. It's just what they would do as engineers. Hodgkinson said everyone knows about thermal expansion and would be aiming for just under 16:1.

The huge story was that Mercedes went above 16:1 because there was no test at operating conditions.

[f1isgood]

I doubt this.

If compression ratio decreases usually I dont see why this isnt the case. Didn't you give a good explanation yourself that this can happen simply based on thermal expansion when I asked for a clarification on dropping from 16 to 15.2 being more than 5%?

Of course it could be the case that the engine manufacturers have better material scientists at the end of the day that doesnt allow such a drop but I would be surprised if it didnt... there's no reason to create a huge story otherwise (imo).

It's likely that the other manufacturers have done work specifically to maintain a 16:1 compression ratio where it otherwise normally drop. It's just what they would do as engineers. Hodgkinson said everyone knows about thermal expansion and would be aiming for just under 16:1.

The huge story was that Mercedes went above 16:1.

I remember that defensive Hodgkinson interview. You could be right and whatever I am reading online might be wrong. We will know either way in a week the advantage Mercedes carries. I suspect its a lot. But let's hope I am wrong.

[AR3-GP]

I remember that defensive Hodgkinson interview. You could be right and whatever I am reading online might be wrong. We will know either way in a week the advantage Mercedes carries. I suspect its a lot. But let's hope I am wrong.

Imo people have mistakenly concluded that Mercedes engineers have a monopoly on intelligence. That's mostly fantasy. There's enough of it to go around. Any of the other manufacturers could work up their own solutions to get above 16:1 in 6-12 months if it had been their intention from the outset.

The only "trick" Mercedes has done is to trick the FIA into making a change to the wording of the regulations so they could go above 16:1. The others are most likely running at 16:1 by having a good understanding of thermal expansion, as Hodgkinson said. Without that, you will just lose compression ratio.

[dia6olo]

I remember that defensive Hodgkinson interview. You could be right and whatever I am reading online might be wrong. We will know either way in a week the advantage Mercedes carries. I suspect its a lot. But let's hope I am wrong.

Imo people have mistakenly concluded that Mercedes engineers have a monopoly on intelligence. That's mostly fantasy. There's enough of it to go around. Any of the other manufacturers could work up their own solutions to get above 16:1 in 6-12 months if it had been their intention from the outset.

The only "trick" Mercedes has done is to trick the FIA into making a change to the wording of the regulations so they could go above 16:1. The others are most likely running at 16:1 by having a good understanding of thermal expansion, as Hodgkinson said. Without that, you will just lose compression ratio.

My feelings exactly. People are still stuck with it's "Mercedes" and how their PU was significantly better with the new rules in 2014.
Reality is the circumstances were very different then. On top of that, Mercedes abused the system leading up to that set of new rules, FIA allowed it & other manufacturers were asleep.
That's not to say that Mercedes couldn't still have the best PU, but to say that if they still do it'll be marginal at best (if operating within the rules).