2.4 L v8 90' degree V angle

[West]

Just hope the rules bring more competition, regardless of the "dumbing down" of the sport. Besides, creating a V8 will be a new challenge anyway

[dron]

To win Shumacher modern F1 doesn't need any schemes of engines or etc. It's just need rain & Ayrton Senna. And nothing else metter!

[Guest]

why would it cause more friction, a v8 revs a couple thousand less then a ten, and also creates more torque. besides the car manufacturers may be better of with a v8 as it is a much more widely used configuration than a v10, thus benefiting more to the auto industry. also the v8 sound is quite spectacular.

the sound is dependent on the crank configuation, the 90 degree crank throw being the best, like nascar. the 180 degree crank throw,makes sound like a 4 cylinder fast and furious, punky mobile.

[DaveKillens]

Engineers, when given a clean sheet of paper for an engine design, will go through thousands of hours of preliminary design work. They examine one, two, three, four, etc cylinder designs for the rules they have to meet.
Each cylinder generates friction. Each cylinder has cam lobes, valves, a piston, and other related moving parts. And each moving part has friction. So logically, a two cylinder engine has more friction than a single cylinder, and so on and so on. But the smaller the combustion chamber, theoretically, you can achieve more power.
So having more cylinders is a good thing, but each cylinder adds a certain amount of friction. At a certain point, the engineers see a set of crossed lines on a graph, and it tells them that for a certain application, ten cylinders is better than twelve. Or something like that.
But in the argument of 8 vs 10 vs 12, things like vibration have to be taken into consideration. I'm not going to explain the causes of primary, secondary, and additional vibration. But trust me, having something like a 72 degree V- 10 (like Renault had) is a vibration nightmare. In fact, they abandonded this successfulll design becuase of reliability issues... from the vibration that would result in a V- 10 with 72 degree bank angle. So when you start talking V 8 or V 10 and mention certain bank angles.. you may be describing a vibration nightmare.
As far as beautiful engine sounds... an older Ferrari V-12 ( eg, a P4) is a very sweet bit of music.

[riff_raff]

Dave,

It's my understanding that back in the late 80's/early '90s, when there was a switch from turbo to NA engines in F1, Renault did extensive parametric studies on the optimum 3.5L race engine configuration: V8, V10 or V12. They determined that a 350cc/cyl V10 offered the best compromise with regards to packaging, weight and efficiency. They must have guessed right because their V10 dominated the V8 of Cosworth and the V12s of Honda and Ferrari.

However, as a general rule of thumb in engine design, for a given power output, a large displacement engine with a minimum number of cylinders running at slow speed, will be more efficient than a small displacement engine with a large number of cylinders running at high speed. This is because FMEP losses (mechanical friction, pumping losses, etc.) increase exponentially with engine speed. Of course, this ignores engine power density (HP per lb.) and package size.

Like everything else in this world, engine design is always an exercise in compromise. That is why all F1 engines eventually became V10s. By trial and error, that was the configuration that proved best. Of course, after everyone migrated to that design, the FIA then made it the de-facto standard per rules.

[dumrick]

Let's also not forget that FIA made the V10's mandatory. Otherwise, with the capacity reduction to 3 liters, I bet that some research would begin to be made again on V8's.

[Reca]

So logically, a two cylinder engine has more friction than a single cylinder, and so on and so on.

To make a meaningful comparison, you have to define the hypothesis of the comparison, hence, a fixed total displacement, a given rpm, a given bore/stroke, same materials and generally the same technological level (to compare an excellent single with a crappy twin is pointless).
Then, given the hypothesis, you can isolate the number of cylinders as the main variable, and the result is : more cylinders = less friction.

But the smaller the combustion chamber, theoretically, you can achieve more power.

It’s not the volume of the combustion chamber the variable making an engine with more cylinder to theoretically achieve more power, it’s the piston area.
Consider a single cylinder of given displacement and fixed combustion chamber volume (hence fixed compression ratio), the power theoretically achievable growths increasing the bore/stroke ratio, hence increasing the piston area. The same applies while comparing engines with different number of cylinders, the more cylinders the larger the piston area can be, everything else being equal, and this will allow to achieve more power.

As far as beautiful engine sounds... an older Ferrari V-12 ( eg, a P4) is a very sweet bit of music.

Well, in the end there’s something we agree about.

However, as a general rule of thumb in engine design, for a given power output, a large displacement engine with a minimum number of cylinders running at slow speed, will be more efficient than a small displacement engine with a large number of cylinders running at high speed. This is because FMEP losses (mechanical friction, pumping losses, etc.) increase exponentially with engine speed.

The fallacy of this mythical argument, claimed over and over (alongside the senseless “longer stroke = more torque”) is that the “engine speed” you have to consider isn’t the engine rpm, it’s the piston average velocity; FMEP (only mechanical friction, to include also the pumping losses is a wrong, although sometimes adopted, approach) is proportional to a power between 2 and 3 of piston average velocity. The point in increase the number of cylinders is exactly the reduction of the stroke, hence of the piston average velocity for the same rpm, resulting in lower power losses at the same rpm; the same power losses will occur at the same piston average velocity hence at higher rpm, but there the engine with more cylinders will also give more power.

Let's also not forget that FIA made the V10's mandatory. Otherwise, with the capacity reduction to 3 liters, I bet that some research would begin to be made again on V8's.

I think you would lose your money then, at the time the V10 was made mandatory because Toyota was planning to enter with a V12, not with a V8.

[riff_raff]

Just as a side note to this conversation, back in 1995, I was given a tour of the Cosworth facility in So. Calif. In the engine assembly area, I saw the 3.5L V8 F1 engine that Michael Schumacher (driving for Benetton) had just won the German GP with, being torn down. I recall picking up the crankshaft and marvelling at how small and light it was. It could not have weighed more than about 10 or 12 lbs, and it was capable of transmitting more than 600 HP.

That was 10 years ago, so I'm sure the internal components of current F1 engines are even more impressive!

[Reca]

Still talking about weight of parts, in 2001 at my Uni we had a series of meetings with Ducati engineers. They showed us several comparisons between parts from the official SBK race bike and the corresponding part on the original bike, the 996R IIRC. The definition “derived from production” takes a new meaning when you see that most of race parts are between 40 and 70% lighter than the originals, especially considering that a production Ducati is already a pretty good piece of machinery.

[riff_raff]

Back when high-rpm race engines had metal valve springs, the fatigue life of the highly stressed valve springs was usually the limiting factor with regards to race engine life. Now, F1 engines use pneumatic valve return springs, so the life of the race engines is usually determined by the fatigue limit of the next most-highly-stressed component: the crankshaft.

Stresses on the crankshaft can be reduced by several methods: adding counterweights, increasing rod/main journal diameter and overlap, decreasing crankshaft length and increasing stiffness/frequency, and minimizing torsional excursions by adding dampeners or flywheel mass. Of course, all of these options (except minimizing length) add weight and decrease throttle response, which is not desireable in a race engine.

Several years ago, I was an engine designer for a factory IMSA GTP race team. We determined through analysis and testing that our race engine cranks would last about 16 hours at race power levels. Sure enough, like clockwork, the cranks would fail at about 16 hours. Fortunately, all of our races were 12 hours or less, with the exception of Daytona.

Finally, here's an interesting news bit from Cosworth: http://www.grandprix.com/ns/ns14635.html
Their new 2.4L V8 F1 engine is running reliably at 20K rpm. Why? Primarily because the torsional vibration issues with a short, 4-pin V8 crank are easier to deal with than the longer 5-pin V10 crank.

[Scuderia_Russ]

Do you think that Red Bull Racing were a little short sighted going to Ferrari engines in this case? Will they be doomed to underachieving like Sauber has continued to do this year? Cosworth have a long history of v8's and this years v10 is certainly up there. What would you have gone with?

[bcsolutions]

Cosworth have a long history of v8's

Ferrari also have a long history of V8's. I have to admit i was surprised that Red Bull decided to go with Ferrari engines under the current F1 climate. Probably a very political maneuver. On the basis of their performance last year i think the Ferrari engine is probably a safe bet for the top three engines next year though!

[Stuart30]

I believe that as time goes on the v-8s will be at 900hp+ as well. The current 3.0L v-10's did not start out making the same power they make now. As for the sound being like a four cylinder. I've listened to IRL v-8's and they sound pretty sucky, but I've also listened to 4 cyl jap motorcycles at 15,000 rpm and they sound pretty damn good. The v-8's being in that higher rpm band should have them sounding good as well.

[bcsolutions]

An F1 spec, 20,000rpm, v8, how could anyone think this engine will sound anything like any other engine built today, it won't.

[riff_raff]

Whether it's a 5-into-1 header on a V10 or a 4-into-1 header on a V8, as long as it's an even firing interval (72 deg or 90 deg) it will sound pleasant to the discriminating ear. It's the oddball-firing-order engine exhausts, like a 45 deg V2 Harley, that sound obnoxious.

Regards,
Terry