What are possible changes to an engine after a non-software upgrade?

[daniellammers]

I know this is a weird question, but I couldn't rephrase it better.

- Are the tolerances changing?
- A change of materials?

A changed bore/stroke is unlikely right?

[NL_Fer]

New injector, redesigned piston crown

[gruntguru]

Bore and stroke are fixed by the rules.

[e36jon]

Apologies for the possibly low-tech reply: Look at all the "bolt-on" go-fast parts you can buy for your car. New intake manifold? 'Cold air intake' (I cringe, but this is the same as the passage from the roll-hoop to the inlet of the turbo on an F1 car...). Headers (You'll see lots of F1 headers for sale and a good % of them were only ever used on the dyno...)? Improved ancillaries like the cooling, fuel and oil pumps? And on and on...

Hope this was close to what you are looking for?

[daniellammers]

Bore and stroke are fixed by the rules.

Wow I see, thought it was just the 1600cc. The bore must be 80mm. Why is that regulated?

[daniellammers]

Apologies for the possibly low-tech reply: Look at all the "bolt-on" go-fast parts you can buy for your car. New intake manifold? 'Cold air intake' (I cringe, but this is the same as the passage from the roll-hoop to the inlet of the turbo on an F1 car...). Headers (You'll see lots of F1 headers for sale and a good % of them were only ever used on the dyno...)? Improved ancillaries like the cooling, fuel and oil pumps? And on and on...

Hope this was close to what you are looking for?

This makes sense. Thanks!

[Craigy]

Bore and stroke are fixed by the rules.

Wow I see, thought it was just the 1600cc. The bore must be 80mm. Why is that regulated?

If that wasn't regulated, the teams would likely go for smaller bores and a longer stroke while keeping piston speeds in a sensible range. Longer stroke = more capability to extract energy, at the cost of lower rev limit etc.

Smaller piston faces leak less heat into the head.

[Big Tea]

Bore and stroke are fixed by the rules.

Wow I see, thought it was just the 1600cc. The bore must be 80mm. Why is that regulated?

If that wasn't regulated, the teams would likely go for smaller bores and a longer stroke while keeping piston speeds in a sensible range. Longer stroke = more capability to extract energy, at the cost of lower rev limit etc.

Smaller piston faces leak less heat into the head.

If they did, as the 'v' angle is set would it not make a 'taller' engine and rise the c.o.g? (longer crank throw etc?)
It would not seem a good trade off?

[Craigy]

Wow I see, thought it was just the 1600cc. The bore must be 80mm. Why is that regulated?

If that wasn't regulated, the teams would likely go for smaller bores and a longer stroke while keeping piston speeds in a sensible range. Longer stroke = more capability to extract energy, at the cost of lower rev limit etc.

Smaller piston faces leak less heat into the head.

If they did, as the 'v' angle is set would it not make a 'taller' engine and rise the c.o.g? (longer crank throw etc?)
It would not seem a good trade off?

The PU CoG is also set in the regs. Section 5.4 of the technical regs at https://www.fia.com/regulation/category/110

[Big Tea]

If that wasn't regulated, the teams would likely go for smaller bores and a longer stroke while keeping piston speeds in a sensible range. Longer stroke = more capability to extract energy, at the cost of lower rev limit etc.

Smaller piston faces leak less heat into the head.

If they did, as the 'v' angle is set would it not make a 'taller' engine and rise the c.o.g? (longer crank throw etc?)
It would not seem a good trade off?

The PU CoG is also set in the regs. Section 5.4 of the technical regs at https://www.fia.com/regulation/category/110

Could they then alter the stroke/throw without affecting this?
I knew the corner and front rear was limited, but did not realise c.o.g of the engine was. How does this affect the positioning of things like turbo and ERS motor? Sounds even more restrictive than I had thought.

[Craigy]

If they did, as the 'v' angle is set would it not make a 'taller' engine and rise the c.o.g? (longer crank throw etc?)
It would not seem a good trade off?

The PU CoG is also set in the regs. Section 5.4 of the technical regs at https://www.fia.com/regulation/category/110

Could they then alter the stroke/throw without affecting this?
I knew the corner and front rear was limited, but did not realise c.o.g of the engine was. How does this affect the positioning of things like turbo and ERS motor? Sounds even more restrictive than I had thought.

5.3 Power unit dimensions :
5.3.1 Cylinder bore diameter must be 80mm (+/- 0.1mm).
5.3.2 The crankshaft centre line must lie on the car centre plane and 90mm (+/-0.5mm) above the
reference plane. The power unit may only transmit torque to the gearbox by means of a single
output shaft that must be co-axial with the crankshaft. The output shaft must rotate clockwise
when viewed from the front of the car.
5.3.3 Valve stem diameter must not be less than 4.95mm.
5.3.4 The crankshaft main bearing journal diameter (measured on the crankshaft) must not be less
than 43.95 mm.
5.3.5 The crankshaft crank pin bearing journal diameter (measured on the crankshaft) must not be
less than 37.95mm.
5.3.6 No cylinder of the engine may have a geometric compression ratio higher than 18.0.
5.3.7 All elements of the power unit specified in the relevant column of the table in Appendix 2 of
these regulations must be installed in the union of the volumes that exist between two vertical
planes parallel to C-C separated by 700mm and in a box 150mm long, 250mm wide and
800mm high which lies symmetrically about the car centre plane immediately ahead of the
front vertical plane.
5.3.8 Power unit mountings may only comprise six M12 studs for connection to the survival cell and
six M12 studs for connection to the transmission. All studs must be used and may be fitted on
the survival cell, power unit or transmission. The installed end of the studs must be M12 and
the free end may be a different diameter.
The mounting faces of the studs for connection to the survival cell must lie on the forward of
the two planes described in Article 5.3.7 and be located at Y215/Z15(2), Y340/Z260(2) and
Y175/Z420(2).
The mounting faces of the studs for connection to the transmission must lie on one vertical
plane parallel to C-C and be located at Y100/Z15(2), Y150/Z140(2) and Y255/Z345(2).
A tolerance of +/- 0.2mm will be permitted on all of the above dimensions, all dimensions refer
to the centre of the studs.
The distance between the two planes is fixed at 480mm (+/-0.2mm).
Any part which provides an additional load path from the survival cell to the gearbox, with a
connection to the power unit, may only do so if this is incidental to its principal purpose.

5.4 Weight and centre of gravity :
5.4.1 The overall weight of the power unit must be a minimum of 145kg.
5.4.2 The centre of gravity of the power unit may not lie less than 200mm above the reference
plane.
5.4.3 The total weight of the part of the ES that stores energy, i.e. the cells (including any clamping
plates) and electrical connections between cells, must be no less than 20kg and must not
exceed 25kg.
5.4.4 The weight of a piston (with piston-pin, piston-pin retainers and piston rings) may not be less
than 300g.
5.4.5 The weight of a connecting rod (with fasteners, small and big end bearings) may not be less
than 300g.
5.4.6 The weight of the complete crankshaft assembly between the mid positions of the front and
rear main bearing journals (including balance masses, bolts, bungs, O-rings between the
boundaries), may not be less than 5300g. See drawing 8.
5.4.7 When establishing conformity with Articles 5.4.1, 5.4.2 and Appendix 4 of the F1 Sporting
Regulations, the homologated power unit perimeter will be defined in accordance with the
table shown in Appendix 2 of these regulations.

Basically, these are the current 2019 regs for PU weight and relevant sizes.

With regard to changing rod/throw ratios for efficiency, I'm not an expert on that. I think it makes a difference to how "lumpy" the PU torque delivery can be, but ultimately it's not particularly impactful on efficiency/power; I think it affects packaging more, so I suppose all four of the manufacturers will have gone for compact solutions.

Bear in mind article 5.3.2 and there's a sensible upper limit to the size of a throw built into it.

[Big Tea]

The PU CoG is also set in the regs. Section 5.4 of the technical regs at https://www.fia.com/regulation/category/110

Could they then alter the stroke/throw without affecting this?
I knew the corner and front rear was limited, but did not realise c.o.g of the engine was. How does this affect the positioning of things like turbo and ERS motor? Sounds even more restrictive than I had thought.

5.3 Power unit dimensions :
5.3.1 Cylinder bore diameter must be 80mm (+/- 0.1mm).
5.3.2 The crankshaft centre line must lie on the car centre plane and 90mm (+/-0.5mm) above the
reference plane. The power unit may only transmit torque to the gearbox by means of a single
output shaft that must be co-axial with the crankshaft. The output shaft must rotate clockwise
when viewed from the front of the car.
5.3.3 Valve stem diameter must not be less than 4.95mm.
5.3.4 The crankshaft main bearing journal diameter (measured on the crankshaft) must not be less
than 43.95 mm.
5.3.5 The crankshaft crank pin bearing journal diameter (measured on the crankshaft) must not be
less than 37.95mm.
5.3.6 No cylinder of the engine may have a geometric compression ratio higher than 18.0.
5.3.7 All elements of the power unit specified in the relevant column of the table in Appendix 2 of
these regulations must be installed in the union of the volumes that exist between two vertical
planes parallel to C-C separated by 700mm and in a box 150mm long, 250mm wide and
800mm high which lies symmetrically about the car centre plane immediately ahead of the
front vertical plane.
5.3.8 Power unit mountings may only comprise six M12 studs for connection to the survival cell and
six M12 studs for connection to the transmission. All studs must be used and may be fitted on
the survival cell, power unit or transmission. The installed end of the studs must be M12 and
the free end may be a different diameter.
The mounting faces of the studs for connection to the survival cell must lie on the forward of
the two planes described in Article 5.3.7 and be located at Y215/Z15(2), Y340/Z260(2) and
Y175/Z420(2).
The mounting faces of the studs for connection to the transmission must lie on one vertical
plane parallel to C-C and be located at Y100/Z15(2), Y150/Z140(2) and Y255/Z345(2).
A tolerance of +/- 0.2mm will be permitted on all of the above dimensions, all dimensions refer
to the centre of the studs.
The distance between the two planes is fixed at 480mm (+/-0.2mm).
Any part which provides an additional load path from the survival cell to the gearbox, with a
connection to the power unit, may only do so if this is incidental to its principal purpose.

5.4 Weight and centre of gravity :
5.4.1 The overall weight of the power unit must be a minimum of 145kg.
5.4.2 The centre of gravity of the power unit may not lie less than 200mm above the reference
plane.
5.4.3 The total weight of the part of the ES that stores energy, i.e. the cells (including any clamping
plates) and electrical connections between cells, must be no less than 20kg and must not
exceed 25kg.
5.4.4 The weight of a piston (with piston-pin, piston-pin retainers and piston rings) may not be less
than 300g.
5.4.5 The weight of a connecting rod (with fasteners, small and big end bearings) may not be less
than 300g.
5.4.6 The weight of the complete crankshaft assembly between the mid positions of the front and
rear main bearing journals (including balance masses, bolts, bungs, O-rings between the
boundaries), may not be less than 5300g. See drawing 8.
5.4.7 When establishing conformity with Articles 5.4.1, 5.4.2 and Appendix 4 of the F1 Sporting
Regulations, the homologated power unit perimeter will be defined in accordance with the
table shown in Appendix 2 of these regulations.

Basically, these are the current 2019 regs for PU weight and relevant sizes.

With regard to changing rod/throw ratios for efficiency, I'm not an expert on that. I think it makes a difference to how "lumpy" the PU torque delivery can be, but ultimately it's not particularly impactful on efficiency/power; I think it affects packaging more, so I suppose all four of the manufacturers will have gone for compact solutions.

Bear in mind article 5.3.2 and there's a sensible upper limit to the size of a throw built into it.

In the case we are disguising, would not ' 5.4.2 The centre of gravity of the power unit may not lie less than 200mm above the reference plane.' depend on the position of the crank? I know '2 up 2 down' is the same, but all in a line at half stroke would be lower as the 'average' weight is lower? (closer to the mains centre?)

PS, don't go too deep into this, just chatting on on rather than diving. I do not know enough to go too deep.

Edit.
Forget that, just realised 2 pistons lower also lowers the 'average'. Sorry

[Tzk]

The fixed bore diameter + spacing and bank angle jus keeps the cost down. Imagine the engine manufacturers would try tens of different concepts to choose the right one. Now they only need to refine an already chosen concept. This is still very expensive though.

Regarding the bore/stroke and cog, i believe that the weight of the piston and conrod is rather small in comparison to the total engine weight. I‘d assume that pistons and conrods weight about 6kg in total while the engine weights about 100kg.

[Big Tea]

The fixed bore diameter + spacing and bank angle jus keeps the cost down. Imagine the engine manufacturers would try tens of different concepts to choose the right one. Now they only need to refine an already chosen concept. This is still very expensive though.

Regarding the bore/stroke and cog, i believe that the weight of the piston and conrod is rather small in comparison to the total engine weight. I‘d assume that pistons and conrods weight about 6kg in total while the engine weights about 100kg.

My thinking was that if the crank had a longer throw then the distance below the crank centreline would have to be more to allow it to clear the sump, and above the throw to the base of the cylinders, thus rising the whole unit, rather than just the pistons and part of the rods being higher. I am assuming that at the moment the engine is set as low as possible so dropping (extending down) the sump would not be possible.

[saviour stivala]

Bore and stroke are fixed by the rules.

Wow I see, thought it was just the 1600cc. The bore must be 80mm. Why is that regulated?

If that wasn't regulated, the teams would likely go for smaller bores and a longer stroke while keeping piston speeds in a sensible range. Longer stroke = more capability to extract energy, at the cost of lower rev limit etc.

Smaller piston faces leak less heat into the head.

Agree, if the rules didn’t lump the maximum fuel flow rate per hour to the maximum RPM of 10500, these engines would have had a much lower max power speed.