We're all going to have to put this in our signatures. This is one of those "people think it's more complex than it really is" situations.brakeboosted wrote: ↑07 Feb 2026, 15:04It's not effective or dynamic compression, It's geometric compression.
According to who?
I don't pretend to be Mattia Binotto or Hywel Thomas. I'm not an F1 engine engineering expert like them. One thing is certain: the technical teams of at least three engine manufacturers involved in F1 know what they're talking about when they demand that the compression ratio be measured when the engine is hot, regardless of whether it's a geometric ratio or not. Mercedes knows its trick better than anyone, which explains Toto Wolff's nervousness, and Mercedes could be forced by the FIA to propose a solution to counter this loophole. This is what happened in 2019 when Ferrari showed the FIA how to install a second sensor to ensure that no engine manufacturer exploits the flaw in the fuel flow.brakeboosted wrote: ↑07 Feb 2026, 15:04Yes but you need to be aware of what the rules govern. It's not effective or dynamic compression, It's geometric compression. You can measure peak cylinder pressures with a sensor indeed, but again the ruls don't govern that. Nor is that a consistent reading because it changes with air density and humidity. Sensors can't determine geoemtric compression. Only mesurements of the physical swept volume at TDC:BDC.Schumix wrote: ↑07 Feb 2026, 11:23brakeboosted wrote: ↑07 Feb 2026, 00:13
This proposal comes from technical experts. They know what they're talking about because it's their area of expertise. There are methods for measuring the compression ratio when the engine is hot: the engine is started until it reaches its maximum temperature and then shut off. A sensor is inserted through the spark plug or fuel intake ports, and the measurement is taken. But there's no guarantee that this is the method that engine specialists will adopt.
Nevermind reliable, how is it safe for anyone involved. How is the engine started, dissassembled and measured whilst beign kept at a steady temperature. It seem highly improbable to be the solution going forward.
You need to be very specific as to what the rules govern, and that is a massive part the media and friends are missing.
In engineering you can alter thermal expansion by changing the crystal structure of the material. No chemical reactions here. In steel it is mostly negligile but not for aluminum. I don't know much about titanium or magnesium though.dans79 wrote: ↑06 Feb 2026, 18:35I do, my degree is physics. The thermal properties of a material are not determined by its manufacturing process.sucof wrote: ↑06 Feb 2026, 17:56I disagree. Do you actually know meta materials?
They behave differently, you kan kinda program their behaviour.
It is not just holes in a solid block of metal. You can create for example long thin structures that are not parallel or anything to the surface, but going around like spagetti. Then if their temp is risen, they change shape, so the movement of the part that is connected to their end will be larger than simple thermal expansion of that material.
Their is a big difference between lab demonstrations of a concept, and the real world hell of heat and pressure inside an F1 engine. I'd add that the structures you are referencing can move in chaotic ways if the thermal gradient applied to them isn't extremely uniform, and that not something you want inside a high precision engine.
Take a look at the rules.The material you can use for the pistons is very specific. it is specifically stated that piston pins and connecting rods are to be machined, That means subtractive manufacturing not additive (no printing). The crankshaft is one the most tortured components in the engine I would not 3d print that.C15.7.1 Pistons must be produced from one of the following iron-based alloys: AMS 6487, 15cdv6,
42CrMo4, X38CrMoV5-3.
C15.7.2 Piston pins must be manufactured from an iron-based alloy and must be machined from a single
piece of material.
C15.7.3 Connecting rods must be manufactured from iron or titanium-based alloys and must be machined
from a single piece of material with no welded or joined assemblies (other than a bolted big end
cap or an interfered small end bush).
C15.7.4 Crankshafts must be manufactured from an iron-based alloy.
No welding is permitted between the front and rear main bearing journals.
You're using terms like geometric (in bold to bootbrakeboosted wrote: ↑07 Feb 2026, 15:04Yes but you need to be aware of what the rules govern. It's not effective or dynamic compression, It's geometric compression. You can measure peak cylinder pressures with a sensor indeed, but again the ruls don't govern that. Nor is that a consistent reading because it changes with air density and humidity. Sensors can't determine geoemtric compression. Only mesurements of the physical swept volume at TDC:BDC.Schumix wrote: ↑07 Feb 2026, 11:23brakeboosted wrote: ↑07 Feb 2026, 00:13
This proposal comes from technical experts. They know what they're talking about because it's their area of expertise. There are methods for measuring the compression ratio when the engine is hot: the engine is started until it reaches its maximum temperature and then shut off. A sensor is inserted through the spark plug or fuel intake ports, and the measurement is taken. But there's no guarantee that this is the method that engine specialists will adopt.
Nevermind reliable, how is it safe for anyone involved. How is the engine started, dissassembled and measured whilst beign kept at a steady temperature. It seem highly improbable to be the solution going forward.
You need to be very specific as to what the rules govern, and that is a massive part the media and friends are missing.
) and telling the other poster to be specific but falling victim to your own critique. 
).
Fwiw I’ve read in The Race something along the lines of Ferrari perhaps having a little more work to do on energy management than Mercedes - but also that the works teams are ahead in this regard and Ferrari second only to Mercedes. That’s not the same as “not happy”, but it will probably remain a big focus (as it will for all teams tbh).
Komatsu said something similar.f1316 wrote: ↑08 Feb 2026, 19:11Fwiw I’ve read in The Race something along the lines of Ferrari perhaps having a little more work to do on energy management than Mercedes - but also that the works teams are ahead in this regard and Ferrari second only to Mercedes. That’s not the same as “not happy”, but it will probably remain a big focus (as it will for all teams tbh).
It will be very positive (for the sport) if an updated testing procedure for compression ratio is found and implemented right away . For anyone (including Toto) saying that the procedure is in the regulations - and therefore they should leave it as it is - that’s akin to not bringing in more stringent wing flexing tests. The regulation is that the compression ratio can not be more than 16:1 at any time and if teams find a way to take the piss on that, the FIA is well within its rights to update the testing process - as it has multiple times mid season on wings, floors etc (often at Toto’s behest).DoctorRadio wrote: ↑08 Feb 2026, 19:38This.
I expect Ferrari to go on refining what they have while Mercedes will have to test whatever hit they are going to get on the ICE side before Melbourne.
Rules also state aero needs to be rigid and it never was. Sometimes the test is what defines the limit.DJ Downforce wrote: ↑09 Feb 2026, 13:38I'm not an engine expert, but if the rules state the compression ratio must be 16:1 at all times, doesn't that make it illegal?
Completely different circumstances.FittingMechanics wrote: ↑09 Feb 2026, 13:42Rules also state aero needs to be rigid and it never was. Sometimes the test is what defines the limit.DJ Downforce wrote: ↑09 Feb 2026, 13:38I'm not an engine expert, but if the rules state the compression ratio must be 16:1 at all times, doesn't that make it illegal?
