2014-2020 Formula One 1.6l V6 turbo engine formula

[wuzak]

They "TPTB" didn't want a spending arms race to make lighter con rods, thinner journals, or making the crank too light. This is why I suggested a very simple but challenging way to shorten the crank is to use fewer main bearing journals on the crank. Each one you omit shortens the block by at least 43.95mm.

The diameter of the main bearing is 43.95mm, not its length.

And you need the support of 4 main bearings under the loads experienced by these engines.


And, as roon says, the length of the crankshaft is, ultimately, dictated by the bore and bore spacing of the cylinders, plus the offset between banks, if there is one.

[roon]

Unless there would be a beneficial function to a flexible crankshaft (beyond what is commonplace). Flexing axially or within the throws. The reason for the new crankshaft regs is probably just to limit development costs for ever lighter & thinner cranks. But I wonder if one of the manufacturers was doing something clever beyond lightweighting.

I was picturing something like a whirling jump rope, with the crankshaft throw(s) warping outwards at speed to alter stroke & compression, or provide shock absorbtion.

Which leads me to wonder how the FIA inspects swept volume. By CAD drawings? Or by physical inspection during homologation?

[Blackout]

What about camless distribution? Yes variable timing is forbidden but they can "atleast" save space and weight and improve efficiency... can't they? Or is that forbidden too? (must the valves be mechanicaly linked to the crankshaft?)

[Ray Okay]

I think they use pneumatic valve springs in current F1 engines, Renault had expiremented with Electromagnetvalves making camshaft obsolete. But i dont think thats legal under current regs?

[godlameroso]

5.1.8 Engines must have two inlet and two exhaust valves per cylinder.
Only reciprocating poppet valves with axial displacement are permitted.
The sealing interface between the moving valve component and the stationary engine component must be circular.

"Reciprocating motion, also called reciprocation, is a repetitive up-and-down or back-and-forth linear motion."
https://en.wikipedia.org/wiki/Reciprocating_motion

The rules state that the valves must open and close in a linear motion, it doesn't say they have to be driven by camshafts. Just that you have standard poppet valves that open and close along the length of their stems, and that the valves and the seats have to be circular. You could in theory use something other than camshafts.

Edit:
5.9.2 Variable valve timing and variable valve lift profile systems are not permitted.

I guess you could still technically not need camshafts as long as your system had fixed valve timing and lift, and not have variable profiles of valve operation.

Such a system could certainly help you experiment with firing orders, as you wouldn't need to cut a new camshaft to try a new firing order, also you could have a fixed profile but you could set any timing lift and duration you wanted within that restriction.

[Brian Coat]

Edit: Posted in wrong thread

[Ray Okay]

I think the real benefit of using electro magnets instead of a camshaft is the ability have variable valve timing and lift controlled by the ECU. With those options banned maybe the conventional camshaft is more efficiënt?

[shady]

I mean, all that mass in the head of an engine could be removed, its beneficial.

[godlameroso]

I think the real benefit of using electro magnets instead of a camshaft is the ability have variable valve timing and lift controlled by the ECU. With those options banned maybe the conventional camshaft is more efficiënt?

Like I said, maybe such a device is good for testing, and then when you find a configuration you like, commit to the two pairs of camshafts. Imagine having to try out hundreds of different grinds to get what you're looking for. Electronically controlled valves at least for engine development would be worth it. Each camshaft takes a while to make, and then test, with an electronic valve system, you could create whatever valve profile you want, whatever lift, duration, firing order your crank can support. So instead of having to make 4 cams and a crank to match, you just use the system, and can spend you effort in making better cranks.

[Ray Okay]

Optimizing in software has great advantages over having to making physical parts, especially during testing maybe even free practice? And removing the camshafts and infrastucture (housing/oil/seals) will improve weight and size. But your replacing them by allot of very powerfull electro hydraulic or magnet valve actuators, i'm sure there still is a weight advantage with the camless solution. Other sollutions are available, i'm just guessing for current engine spec, camshafts are still mandatory or more efficient.

http://scarbsf1.com/valves.html

[gruntguru]

Slightly longer video from Koenigsegg. Claims 50% volume and 30% mass reduction for valve gear.

Note: the Freevalve system does not have full control of the lift "profile". It has full control of the timing of the opening and closing events. The actual opening and closing events happen at a fixed rate (variable to some extent by varying air pressure). Essentially opening and closing events involve extreme accelerations and there is little that can be done to re-shape the profile (whether conventional or camless) without reducing the area under the curve.

[roon]

Thanks, gg. The point about high speed control limits makes sense. Keeping in mind the efficiency formula, one wonders what is left to be optimized in the valvetrain. Do springless, captive cam (desmodromic) systems consume less engine power? On one hand, they have more cam-riding surfaces. I assume a spring loaded valve, while consuming energy to compress the spring, returns some energy to the system upon valve closing. I'd wager an F1 optimized convential cam drive is pretty efficient & lightweight as-is. Maybe roller bearings are employed in the current formula.

These camless systems would surely have been considered if they are as efficient as they claim to be, although durability & development payoff are considerations as well. To the latter: how many HP does it take to spin the camshafts?

[Brian Coat]

For a high speed race engine the total head assembly friction will be in the range 0.3-0.4 Bar FMEP.

Roughly 7 hp on one of these?

The high IMEP of the turbocharged engine, plus the MGU-K POWER make this a smaller proportion of output than for a non-hybrid N/A race engine.

[Edis]

A camless system need more power to be driven at high speed and high lift compared to camshafts. For a roadcar engine this isn't much of a problem, since they are mostly operated at part load and low engine speed. At part load is also where the main benefits are with the system, and under such situations the power consumption of the system can be reduced by lower valve lift or by deactivating one of the two inlet valves or whole cylinders.

[erikejw]

Is it allowed during mid corner to inject fuel into the combustion chamber(to have that behaviour when throttle is below 30%) but not ignite it? It could be useful in qualy.