2026 Drama: Alleged engine loophole

[Rodak]

I still think it is worth to think about meta materials.

Think about them all you wish but, from 15.8 Materials, the piston material is defined:

15.8.1 Pistons must be produced from one of the following iron-based alloys: AMS 6487, 15cdv6,
42CrMo4, X38CrMoV5-3

[vorticism]

There are mechanical and thermal metamaterials that make use of homogeneous materials. Whether micro printed lattice steels can supply such effects at several hundred bar and several hundred degC, would be the question. All told, the geo compression ratio is prescribed. If an unusual material choice (steel block, heads, and cam covers) or unusual construction (metamaterials) were chosen then you'd need fake or coincident reasons to give to the FIA for your choices, because they and other teams will assume you're trying to circumvent 16:1 in an undetectable way. Why else pursue those arrangements.

That's part of why I think alteration of compression ratio isn't the trick at play, regardless of how, including thermal expansion. The end result is too blatantly in violation. The "can't confirm nor deny" defense only goes so far, and you will have sunk untold cost into something too easily banned. I'll hold to supporting that the trickery has nothing to do with altering GCR via TE or other means.

[sucof]

I still think it is worth to think about meta materials.

Think about them all you wish but, from 15.8 Materials, the piston material is defined:

15.8.1 Pistons must be produced from one of the following iron-based alloys: AMS 6487, 15cdv6,
42CrMo4, X38CrMoV5-3

I presume you do not really know what a metamaterial is then.
It is the same allowed material, but it is usually printed in 3D, to have some mechanical structure that deforms in a pre determined way, that is beneficial. Like wings which does not bend till a certain (FIA measurement) strength, but at higher forces suddenly start to bend more.

[sucof]

There are mechanical and thermal metamaterials that make use of homogeneous materials. Whether micro or nano printed lattice steels can supply such effects at several hundred bar and several hundred degC, would be the question. All told, the geo compression ratio is prescribed. If an unusual material choice (steel block, heads, and cam covers) or unusual construction (metamaterials) were chosen then you'd need fake or coincident reasons to give to the FIA for your choices, because they and other teams will assume you're trying to circumvent 16:1 in an undetectable way. Why else pursue those arrangements.

That's part of why I think alteration of compression ratio isn't the trick at play, regardless of how, including thermal expansion. The end result is too blatantly in violation. The "can't confirm nor deny" defense only goes so far, and you will have sunk untold cost into something too easily banned. I'll hold to supporting that the trickery has nothing to do with altering GCR via TE or other means.

I see possibilities here for such arguments, like cooling or durability...

But in general, as I wrote earlier, I agree with your second statement that this might be also smoke and mirrors from Toto or Mercedes in general, to make other teams and FIA to spend time and energy to look at the wrong places.
You know: SQUIRREL!!!!!

[Tommy Cookers]

so a steel or other iron-based engine block is possible ie 6 ppm/deg F expansion
for the rods established iron-based alloys (and mandated iron-based piston alloy) will give 9 ppm
these will do the '16-18 trick' (as I said a week ago)
the crank & rods & piston are hotter and more expansive than the block

(BY MISTAKE EDITED MY POST 29th AS ABOVE )

established iron-based alloys for rods etc are 6 or 7 ppm/deg F
a 'cobalted Invar' engine block would have 0.3 ppm expansion and enough strength (Super Invar UTS c. 32 tons/sq in)
this combination would do the '16-18' easily ....

but we can also do the '16-18' with a block made from ArcelorMittal's 'Hardened Invar' ....
it's hard and strong (UTS 65-75 tons/sq in) by heat treatment or cold working - and it's only 1.5 ppm expansion ....
the properties are readily manufacturer-customised eg expansion matched to design temperature

and consider ...
some big diesels are made by welding steel parts together
and iirc the Crosley engine was originally a 'copper-brazed' all-steel engine made from welded sheet and pressings
air cooled ? - later water cooled (ok now replacement blocks are conventional cast iron)
WDCs & F1 races were won by eg turbocharged BMW and Renault cast iron blocks (with alloy heads of course)
Berger's Benetton-BMW has held the record (218 mph) since 1985

[chrisc90]

Thinking outside the box…

Anything that limiting the head gasket or head bolts?

[FW17]

I still think it is worth to think about meta materials.

Think about them all you wish but, from 15.8 Materials, the piston material is defined:

15.8.1 Pistons must be produced from one of the following iron-based alloys: AMS 6487, 15cdv6,
42CrMo4, X38CrMoV5-3

I presume you do not really know what a metamaterial is then.
It is the same allowed material, but it is usually printed in 3D, to have some mechanical structure that deforms in a pre determined way, that is beneficial. Like wings which does not bend till a certain (FIA measurement) strength, but at higher forces suddenly start to bend more.

Printing it may not be structurally great. They could take the piston crown and add a whole lot of thin cnc machined lines like 0.1mm wide and a couple of mm deep that all close up when engine gets to temperature.

Function is 2 fold

1. Help the entire piston crown to not expand towards the cylinder wall expanding inward.
2. Improve the compression ratio from 16:1 to higher

[Hoffman900]

Racing engine builders from amatuer to oem pro builders have been running a net zero piston to head clearance forever. This always makes the most power. Drag racers, NASCAR, F1 builders, etc run the P-H so they just sliggghtly kiss. This is due to thermal expansion and rod stretching. Anything less is just for a safety margin, at the expense of some power.

F1 builders run very small, compact combustion chambers. Any growth here will effect valve sealing, which is very critical.

Temperarures across the piston, bore, wrist pins, valves, valve seats, chamber walls are not the same. So controlled growth here is very hard to manage. Also materials and dimensions are highly regulated. Managing piston blowby and and valve sealing / reliability matters immensly here and there is big power to give up in letting them slip.

To me, it seems it’s just a rules snafu where teams are actually probably seeing a change from 16:1 to 16.1ish:1 geometric compression in a running engine, which is not what the rules allow.

Most of this is a silly season distraction, people who don’t know race engine building / design, and generative AI / fantasy slop.

[FW17]

Racing engine builders from amatuer to oem pro builders have been running a net zero piston to head clearance forever. This always makes the most power. Drag racers, NASCAR, F1 builders, etc run the P-H so they just sliggghtly kiss. This is due to thermal expansion and rod stretching. Anything less is just for a safety margin, at the expense of some power.

F1 builders run very small, compact combustion chambers. Any growth here will effect valve sealing, which is very critical.

Temperarures across the piston, bore, wrist pins, valves, valve seats, chamber walls are not the same. So controlled growth here is very hard to manage. Also materials and dimensions are highly regulated. Managing piston blowby and and valve sealing / reliability matters immensly here and there is big power to give up in letting them slip.

To me, it seems it’s just a rules snafu where teams are actually probably seeing a change from 16:1 to 16.1ish:1 geometric compression in a running engine, which is not what the rules allow.

Most of this is a silly season distraction, people who don’t know race engine building / design, and generative AI / fantasy slop.

Geee, thanks for reminding what we learnt in kindergarten

[atanatizante]

This topic is a load of bollocks! And I'm not the one who is telling this thing but rather real enginners with lots of expertize in this area: (use CC to translate)

The guy didn't say it is bollocks. He said they could use a layered cylinder head to create bulging into the combustion chamber at operating temperature. What did you take from it?

Ok, maybe you're right about this topic coz is above my level of knowledge ...
Then how about the fuel topic? I don't have any feedback to a particular thread that discuss this matter... btw, do you have an opinion about this fuel subject?

[Tommy Cookers]

Then how about the fuel topic? I don't have any feedback to a particular thread that discuss this matter... btw, do you have an opinion about this fuel subject?

well I read the post 2 pages ago
yes perhaps the FIA are too busy (still adjusting the other rules) to justify to the public the fuel rules

I think that anyone can start a thread on this topic ?
maybe in this section or in the section 'Engine, transmission & controls'

there may be a danger of such a thread being seen as too 'political'

[hollus]

Anyone can start a thread, yes. It can always be moved afterwards if necessary.

[WardenOfTheNorth]

Racing engine builders from amatuer to oem pro builders have been running a net zero piston to head clearance forever. This always makes the most power. Drag racers, NASCAR, F1 builders, etc run the P-H so they just sliggghtly kiss. This is due to thermal expansion and rod stretching. Anything less is just for a safety margin, at the expense of some power.

F1 builders run very small, compact combustion chambers. Any growth here will effect valve sealing, which is very critical.

Temperarures across the piston, bore, wrist pins, valves, valve seats, chamber walls are not the same. So controlled growth here is very hard to manage. Also materials and dimensions are highly regulated. Managing piston blowby and and valve sealing / reliability matters immensly here and there is big power to give up in letting them slip.

To me, it seems it’s just a rules snafu where teams are actually probably seeing a change from 16:1 to 16.1ish:1 geometric compression in a running engine, which is not what the rules allow.

Most of this is a silly season distraction, people who don’t know race engine building / design, and generative AI / fantasy slop.

Geee, thanks for reminding what we learnt in kindergarten

Which kindergarten did you go to??

[piast9]

I have a question. Where did 18:1 effective compression ratio figure came from? Who did report it? I only saw some media speculation about that value.

18:1 was in the old regulation set.
And if you are a newspaper looking for drama, it makes a nice villain and sounds optimal and hence dooms-day-y. IMHO.
The real target may also be 16.3, and the real gain might be 2-3 hp, if any.
Or not, of course.
AFAICT there is zero solid sources for restoring 18:1.

This is my thinking too. I suspect that Merc and Red Bull just asked for clarification because they've realised that if they use the materials they intended then if they start with 16:1 at room temperature the compression ratio may increase a bit when engine gets hot.

I don't remember exactly the number but I did some calculations when this drama started and a jump to 16.3:1 may be the result by conrod expanding linearly by few tens of microns more than the crankshaft - head distance, which is nothing unexpected from normal materials thermal expansion ratios.

[saviour stivala]

A formula 1 ''off-season - winter break'' needs some sort of 'drama'/'gossip' as otherwise there will not be much to talk about. What made this one this time looks real was the FIA sort of acknowledge what was pushed out, but what nobody is realizing is that the FIA needs such off season/winter break drama as much if not more than the F1 media to keep the spirt going. This sort of so called 'compression gain by thermal expansion' of engine parts was always there and under control by design, it is now being called a loophole because compression was this time mandated as being reduced from 18:1 to 16:1. I personally believe that because material are regulated, the situation will be the same for a five ICE manufacturers.