2014-2020 Formula One 1.6l V6 turbo engine formula

[tuj]

RBR runs today on the RAAF runways after their 'filming' is over. I wonder if they have solved enough of the Renault/heat problems to make it all the way through the GP this weekend?

[321apex]

The Mercedes video depicting cranktrain of an alledged '14 F1 engine is highly unrealistic.
Why? Con rods don't share the crankpin, but are riding on a split journal a'la typical practice for even firing V6.

Although it may not be excluded that MB follows some unconventional path to crankshaft configuration, the kinematic requirement of shared crankpin demands their scatter to be equaly spaced around 360 deg circle, ie 120 deg spans.

It is true that under such crank arrangement there are several possibilities for cylinder firing sequence, which may manifest itself thru an odd sounding exhaust note.

[twoshots]

The Mercedes video depicting cranktrain of an alledged '14 F1 engine is highly unrealistic.
Why? Con rods don't share the crankpin, but are riding on a split journal a'la typical practice for even firing V6.

Except that the 2014 F1 results specifically require shared pins...

[Tommy Cookers]

the 1st generation Laverda 3 cyl inline motorcycle engine had a flat 0deg-180deg-0/360deg crankshaft
this type of flat crankshaft layout would (by counterweighting) allow our 90 deg V6 to cancel all primary frequency imbalance
though there would be some secondary imbalance (vibration), in principle as with the 2013 etc V8s
3 shared crankpin axes
(also of course the same could result from a single crankpin axist 0 deg-0 deg-0 deg crankshaft)
a bit like bolting together 3 Ducati V twins in various ways

the 3 axes arrangement seems the better
firing at 0/(720)deg,90deg,270deg,360deg,450deg,540deg, or 0/(720) deg,90deg,180,360,450,630deg
(although more-simultaneous firings are also conceivable)
sorry if an earlier poster had this in mind

btw at the reduced rpm of 2014 onwards it seems advantageous to use articulated conrods (master-and-slave)
this would make the engine shorter and reduce the friction related to the lateral component of piston thrust
the rules do not prevent this ?
EDIT after following Wuzak post
fork-and-blade articulated conrods give no side thrust/friction benefit

[ppj13]

The Mercedes video depicting cranktrain of an alledged '14 F1 engine is highly unrealistic.
Why? Con rods don't share the crankpin, but are riding on a split journal a'la typical practice for even firing V6.

Except that the 2014 F1 results specifically require shared pins...

Rules say you must have only three conrod bearing journals in the crankshaft.

You can attach one conrod to the only journal and the other conrod to the first conrod. I've seen it in air compressors.



Besides, it's not so clear to me that a split bearing journal is not still ONE bearing journal. I believe that the rule is to prevent 6 throws (7 crankcase bearings)

Finally, it's mandatory that the banks form 90º, but not that the axis of the cylinders intersect the crackshaft center. You can achieve different phase between banks if the crackshaft centerline is not in the apex of the vee, but slightly above or below.

The renault engine really sounds like equal firing intervals at full throttle. Mercedes one sounds as if half of the ingition coils are toasted

[wuzak]

Master and Slave rod systems woudl not be desireable, since one bank would have a different effective stroke to the other and the rod is so short that the master rod would end up with some funky angles.

Fork and blade would work better, but getting the cap bolts into the fork rod may be a bit of a squeeze.

In any case, the length of the engine (front mounting face to rear/gearbox mounting face) is defined by the rules and is longer than the V6 could be. So the only benefit of the fork and blade system would be a reduction in the side thrust force on the pistons, and I am doubting that this difference would be of any signifigance.

[langwadt]

Master and Slave rod systems woudl not be desireable, since one bank would have a different effective stroke to the other and the rod is so short that the master rod would end up with some funky angles.

Fork and blade would work better, but getting the cap bolts into the fork rod may be a bit of a squeeze.

In any case, the length of the engine (front mounting face to rear/gearbox mounting face) is defined by the rules and is longer than the V6 could be. So the only benefit of the fork and blade system would be a reduction in the side thrust force on the pistons, and I am doubting that this difference would be of any significance.

why would fork and blade reduce side trust?

[wuzak]

Master and Slave rod systems woudl not be desireable, since one bank would have a different effective stroke to the other and the rod is so short that the master rod would end up with some funky angles.

Fork and blade would work better, but getting the cap bolts into the fork rod may be a bit of a squeeze.

In any case, the length of the engine (front mounting face to rear/gearbox mounting face) is defined by the rules and is longer than the V6 could be. So the only benefit of the fork and blade system would be a reduction in the side thrust force on the pistons, and I am doubting that this difference would be of any significance.

why would fork and blade reduce side trust?

They wouldn't. It was something that was mentioned by another poster, which has been corrected now.

[ringo]

How do you lubricate that bearing with the slave con rod?
Maybe that's why it's used in a compressor and not an engine.

[Tommy Cookers]

just about every aircraft piston engine had master-and-slave rods
typically 6 or 8 slaves per master rod (in radial engines)
also all those WW2 V12s and the 3 bank 'broad arrow'/W engines (like the Napier-Railton and the recent Napier-Bentley cars)

the slave rods operate at a more favourable angle (reducing sidethrust and friction)
to minimise engine size the aircraft engine rod ratio would be lower than eg in a car engine, so the above was important
also the slave 'big end' bearings have a low rubbing velocity oscillation (non-rotational), making further savings in frictional losses
the mechanical efficiency of these engines could exceed 90%
there were also benefits of reduced engine length, weight etc

[ppj13]

Master and Slave rod systems woudl not be desireable, since one bank would have a different effective stroke to the other and the rod is so short that the master rod would end up with some funky angles.

No, this is not true. There are many positions in which stroke does not change (for example, the one in the pic for 60º Vees)

How do you lubricate that bearing with the slave con rod?

Same way you lubricate an engine with a crankshaft. You make oil pass from crankshaft to conrod.

I'm not saying funny conrods or V angle positions are being used. But I'm pretty sure the renault engine does not fire at 90 and 150 angles. They did something to even out the firing sequence around a flywheel.

When a team makes an official question to the FIA regarding rules, is it public? Is it possible to read them? Is there a place in which all clarifications are stored?

[Holm86]

[youtube]http://www.youtube.com/watch?feature=pl ... kwpEPJVqTc[/youtube]

[Abarth]

[[...]But I'm pretty sure the renault engine does not fire at 90 and 150 angles.[...]

Why are you pretty sure? Sound of engine?

[...] They did something to even out the firing sequence around a flywheel. [...]

I do not understand "around a flywheel". Can you explain?

Thank you!

[ppj13]

To abarth: yes, sound. Now that you mention, "pretty sure" is too much. I'd better say "suspect".

I have a kind of a trained ear, and these things sing aloud. If you miss a fire in 8, it may go unnoticed. But if you fire unevenly all the time (bang-bang, bang-bang, bang-bang...) the music changes. And the renault, turbo hiss apart, is very much like the old V8 screamer.

As you know the only change in sound from a crossplane V8 to a screamer V8 is (with 8 in 2 pipes) that explosions exit the pipes doing a paradiddle (lrllrlrrlrllrlrr). They both fire every 90 deg. And yet you can tell from miles away which kind of crank each has.

Uneven firing changes the sound even more, it has its music. The 4 cilinder version is motoGP; 6, W05. Hard to miss.

Renault hasn't any.

And "around the flywheel" is just a stupid (and superfluous) choice of words. Just ignore it.

[321apex]

To abarth: yes, sound. Now that you mention, "pretty sure" is too much. I'd better say "suspect".

I have a kind of a trained ear, and these things sing aloud. If you miss a fire in 8, it may go unnoticed. But if you fire unevenly all the time (bang-bang, bang-bang, bang-bang...) the music changes. And the renault, turbo hiss apart, is very much like the old V8 screamer.

Sound by itself can be misleading.
Subaru "boxer" passenger car engines are even firing 4 cylinders while they do sound quite different than an in-line 4. What would your "trained ear" likely suspect ?