2026 Drama: Alleged engine loophole

[Hoffman900]

Mattia hates toto

This is not a personal issue. If it were, then Toto and Binotto do not belong at this level of responsibility, where feelings must be set aside and objectives achieved. This is clearly a matter of regulatory compliance. And if a compression ratio doesn't meet all the regulatory requirements, then the unit price is non-compliant.

Every single rule set with a compression limit measures at ambient, because measuring this on a running / firing engine is silly. Things grow and seeing 1-2pts of geometric compression rise is not unheard of and people have been building race engines this way for decades.

Only the FIA can screw this up, just like they’ve screwed up overtaking with overbearing rules.

[Schumix]

Mattia hates toto

This is not a personal issue. If it were, then Toto and Binotto do not belong at this level of responsibility, where feelings must be set aside and objectives achieved. This is clearly a matter of regulatory compliance. And if a compression ratio doesn't meet all the regulatory requirements, then the unit price is non-compliant.

They do tho. The rules say at ambient. If a manufacturer didn't advantage the ambiguity of the rule, they didn't do their job, and it's on them. The end. See you in 2027.

The key phrase in my statement is "...all the regulatory requirements." And based on what's being discussed, the compression ratio of the Mercedes engine doesn't comply with article C1.5 of the FIA ​​F1 specifications. We'll see what the FIA ​​decides after March 1st, the homologation date for engines for the 2026 season. One thing is certain: after the Ferrari affair in 2019, the FIA ​​is taking a huge risk for F1.

[basti313]

The key phrase in my statement is "...all the regulatory requirements." And based on what's being discussed, the compression ratio of the Mercedes engine doesn't comply with article C1.5 of the FIA ​​F1 specifications.

Well, that is not how F1 works.
Maybe think about the easy case of flexible bodywork: Must not flex by the rule. So they define a test and what passes is complying with this rule.
For the compression ratio they also have a test...what passed is in compliance.

We'll see what the FIA ​​decides after March 1st, the homologation date for engines for the 2026 season. One thing is certain: after the Ferrari affair in 2019, the FIA ​​is taking a huge risk for F1.

Why? I think it is expected that there are (big) differences between the engines. That is why they state since years that they will initiate measures to level the field. A situation like in 2014 till ~2018 will not be tolerated/supported anymore. Everything around this was hurting F1: Mercedes dominance, Ferrari cheat, Honda failure...they will bring it quickly to a level like after 2020.

They will check this season how the engines compete and then level the field for 27. This nice loophole (if it is existing) will not do anything good in 27 but only produce cost.

[Snorked]

AMUS has an article suggesting Mercedes may have a small 1-cubic-centimeter pocket in the spark plug area connected through a small channel. During static tests, this channel remains open to pass the test, but at higher racing temperatures, a pressure valve closes, increasing the ratio.

https://www.auto-motor-und-sport.de/for ... orentrick/

[gearboxtrouble]

AMUS has an article suggesting Mercedes may have a small 1-cubic-centimeter pocket in the spark plug area connected through a small channel. During static tests, this channel remains open to pass the test, but at higher racing temperatures, a pressure valve closes, increasing the ratio.

https://www.auto-motor-und-sport.de/for ... orentrick/

If true (big if given the source) this is a lot less defensible than maximizing stretching and thermal expansion to boost the cr. This seems more like a deliberate breach of the rules and should be illegal to use this season. I understand that Mercedes won’t have the time to change their engines to make them legal but maybe they could be given an electrical power penalty for the season to offset the illegal ice.

[Badger]

AMUS has an article suggesting Mercedes may have a small 1-cubic-centimeter pocket in the spark plug area connected through a small channel. During static tests, this channel remains open to pass the test, but at higher racing temperatures, a pressure valve closes, increasing the ratio.

https://www.auto-motor-und-sport.de/for ... orentrick/

They kind of debunk their own theory at the end by saying that when they asked an engineer about it they said it wouldn't be allowed.

[Hoffman900]

Yeah that’s just tabloid level slop

[motobaleno]

AMUS has an article suggesting Mercedes may have a small 1-cubic-centimeter pocket in the spark plug area connected through a small channel. During static tests, this channel remains open to pass the test, but at higher racing temperatures, a pressure valve closes, increasing the ratio.

https://www.auto-motor-und-sport.de/for ... orentrick/

It seem to me that AMUS doesn't speak about a "pressure valve" but it says that the channel is very very thin and in some way it does not contribute to the chamber volume when hot...something again related to thermal expansion but if so we are talking of a channel of the order of 0.05 mm or less (I would say that such a channel, even if racing engines are very clean, would be soon closed by combustion deposits after few km of running...) ...a solution of this type would seem to me highly illegal. if true what they have done is to realize a proper 18CR combustion chamber with aside a fake minichamber connected by a doomed to disappear capillar channell...it seems a joke to me.

[FrukostScones]

they say this cold be a method to get higher compression ratio but is illgegal by the rules, and as they report Mercedes signed off every step the made with the FIA regarding their PU AMuS basically rules out that Mercedes has done this.

[Hoffman900]

The teams literally submit CAD drawings to the FIA and have for a while of these subsystems, that’s also missed in all of this.

[FW17]

The teams literally submit CAD drawings to the FIA and have for a while of these subsystems, that’s also missed in all of this.

Why would they need to show cavities within blocks?

[amr]

It's possible that there are some rumours escaping to the media, but since they are not engineers, they are not able to make sense of it or read between the lines.

Maybe the way the trick works is to design the engine valves and the valves seat such that when the engine is hot, the valve is not allowed to retreat to the same extent it does when the engine is cold. Therefore, some of the valve body will displace some combustion chamber volume and increase the compression ratio (while also reducing the overall engine cc to a very small extent)
There are 4 valves per cylinder, so a little volume displaced by each valve will add up.

Trying to upload a bad ppt drawing of what I mean.

[AR3-GP]

AMUS has an article suggesting Mercedes may have a small 1-cubic-centimeter pocket in the spark plug area connected through a small channel. During static tests, this channel remains open to pass the test, but at higher racing temperatures, a pressure valve closes, increasing the ratio.

https://www.auto-motor-und-sport.de/for ... orentrick/

This would violate the cubic capacity limits no?

[AR3-GP]

It's possible that there are some rumours escaping to the media, but since they are not engineers, they are not able to make sense of it or read between the lines.

Maybe the way the trick works is to design the engine valves and the valves seat such that when the engine is hot, the valve is not allowed to retreat to the same extent it does when the engine is cold. Therefore, some of the valve body will displace some combustion chamber volume and increase the compression ratio (while also reducing the overall engine cc to a very small extent)
There are 4 valves per cylinder, so a little volume displaced by each valve will add up.

Trying to upload a bad ppt drawing of what I mean.

It is understood

[Hoffman900]

There is not trick. You build engines with a certain amount of piston to head clearance at ambient because it closes up when in a running engine. This is engine building 101 stuff and has held true long before 3d printed materials and everything else was a pipe dream.

Just because F1 media members don’t actually understand this or didn’t know (most have like writing / journalism degrees, and even if they have engineering degrees this isn’t something they teach you).