Why did Ferrari revert to 4-valve engines?

I don't believe they eliminated the 5th valve in F1 motors due to cost.

 

I assumed F1 was 4 valve because Bernie said so, but I have never seen a full set of rules, so I could easily be wrong about that.

 

I do not know if the rule ever changed but Ferrari did it on their own for the sake of engine improvement.

 

The key to making hp with smaller displacement is to increase the max RPM of the engine. One of the biggest stumbling blocks to increasing RPM is valvetrain weight and complexity. If you have three valves to open (intake) instead of two you have a 50% increase in complexity and an increase in weight. Its probably easier to get the needed rpms with 4 valves than 5...??? Thats just my guess.

 

In a 4v each valve assy weighs more than the assy for a 5v.

Complexity was not the issue either, they found a way to make more HP with 4.

It really is that simple.

Some ides do not stand the test of time. Nothing wrong with that.


Roller bearing cranks and desmodromic valves are 2 great sounding ideas that went the way of the dinosaur also.

 

The reasons are at least 2 fold, for ferrari switching from a 5 valve to 4 valve. The Enzo motor is a MUCH larger displacment motor. When you run a big bore(not stroke ) motor, as the piston starts to go down, from top dead center(where its closest the valves) it creates a sudden surge and fills the piston quicker. Simp;y opening the valves doesnt draw the air in..its is the pistons action. To compensate for this lack of bore, they would allow more flowing air potiential.
The MOST powerful piston Engines in the world run how many valves????anyone dare to guess?

 

I'd guess 2...the American V8's used in top fuel drag racing.

Gary

 

Ford went to 3 valve variable timed V8's in 04 as well as the new mustang gt. Works very well, flows more than the 4 cam 32 valve head with pent-roof chamber and costs less. The chamber is like a 3 leaf clover, 2 intake, 1 exhaust single cam. Compromised by having one cam control all 3 with the variable timing but better than fixed 4 valve timing.

 

You knew Jim? Ever go to one of his parties? Pretty outrageous.

Art

 

I may be wrong, but Caprossi won how many MotoGP races this year? Bayliss won the last one too, right? Weren't those Ducatis both with desmo valves?

Art

 

I think Ducati has been using Desmodromic valves for a while. I'm not going to venture a guess which is better in either way because I don't know, though I have learned a lot reading the topic. My only thought is that while some configurations are clearly superior, the application probably plays a role as well, depending on what is needed.

 

Bayliss won the riders and manufacturers title in World Superbike. Again.

Ducati has been using desmo valves since 1957. While the technical advantage that existed when the system was designed (valve springs sucked at the time) are more or less gone, there are still advantages to the system today (like no valve float, ever).

Ducati kept the system largely as it has been a very large part of their heritage, and their customers demand it.

I like five valve heads for the same reason I like desmos. They sound better than a four valve yamaha, and in modern iterations of both, the performance differences are fairly marginal.

Can you pull more power out of a four valve head with less complexity and lower cost? Sure. Will it sound like a 355 at 9,000 rpm? No.

I'm sure there are some technical purists who bash five valve systems for the usual reasons, just like most jap bike riders bash Ducati for their "antiquated" valve system. However, they're dead wrong if they think car and bike builders do a given thing solely because it's cheaper or easier to do so.

Ducati, for example, could easily ditch the desmo system and go to a current valve spring design. No doubt, it would make their racing efforts cheaper and easier. However, it would also tick off their extremely loyal customer base, and as Ducati is one of the last smallish Italian motorworks, they listen to their customers quite closely.

 

Ducati still uses the desmodromic system, because is allows them to use camshaft profiles that could not be used with normal valve springs.

 

Are we sure the MotoGP engine uses Desmo...?

 

NHRA Supoercharged motors based closly upon the 1960s Chrysler hemi put down 10,000-12,000bhp. The Gasoline/streetable versions put down 2-2500hp.
It will be interesting to see what happens when the valves are electrically controlled (ie there is no camshaft, or valve springs, and possibly JUST an exhause valve because the fuel AND air will be directly injected into the cylender). There are rumers and pictures of an AMG prepped Next Gen Viper with a camless engine, electronically controlled valves?!?!? Id dare say tho that the viper will be a 2 valve set up if it is cam or camless.

 

The bike is called the Desmosedici, so, yes. 16 valves, Desmo system.

The difference is, it's a V-4 as opposed to a V-twin.

 

10,000 - 12,000 HP???

I dont know where these numbers come from, or who keeps hyping them, but I do not believe it.

Those engines have not grown in displacement, or in any other way in 40 years, thier still 500 inch. They might pack in a bit more psi but I cant see how in the world they could make almost 5 times more power, burning the same fuel they always have, nitromethane mixed with methanol. Yes, 5 times. 4.8 to be exact

When Don Garlits broke 250 mph in the quarter mile, the magazines and everyone back in the day cited top fuel HP at about 2,500 HP. That power level remained at that figure until goodyear finally figured out tire shake was caused by a lack of HP, and the race was back on. Last I had read back in the late 90's, they were making just shy of 4,000 HP. But there have not been any gigantic increases in ET's or trap speeds since that time.

Then its been getting to where every time I hear someone speak about them over the last 5 or 6 years, its growing by leaps and bounds. Using basic formulas for speed and distance, to accelerate to twice as fast over the same distance, with the same weight, would require 4 times the energy. Seeing as 12,000 HP is 4.8 times what they made in the late 1960's, and seeing todays cars are even lighter, why arent these things blasting through the 1/4 mile in excess of 500 mph? 4,000 HP or so would be more than sufficient to push them through at 300 mph, and anyway you compare it, its a remarkable amount of power. When I read web sites, I am seeing numbers all over the place from 5,000 to over 8,000 HP. To much discrepency for me. Someone good with math could easily calculate the HP of one of these things, I bet its still not much over 4,000.

 

It's actually closer to 100,000 to 120,000 hp . . . What the hell . . . . writing is free, isn't it?

 

I want one of those 120,000 HP engines to drive to work.

I have been getting to work later and later, I think 120,000HP will push all those slow cars out of my way

 

I thought I'd bump this thread, as I came along an old picture of a variable valve-timing concept, quoted as a 'fiat studies' - does that block say Ferrari V8 or what?!

I remember reading on the developement of the 355, the 5-valve head was a side-studies tot the 4-valve var. timing, and found to be more cost-effective and better performing, powerwise. Imagine a valve-job on those tumblers ...
Image Unavailable, Please Login

 

Top fuelers at the moment are running around 8000 hp. Infact most of thier performance gains recently have more to do with the electronic clutch systems enabling the car to hook up, rather than pure horsepower.
BTW who does owne the record for normally aspirated street motor. I think it would be the Enzo.


Darrell.

 

Here is a "wikipedia" article:

Performance
Power output of these engines is most likely somewhere between 6000 and 8000 horsepower (approximately 4500-6000 kilowatts). This is calculated from performance as these engines aren't tested on a dynamometer. This would suggest a torque output of 5100-6750 Nm (3760-4980 lb-ft) and also a brake mean effective pressure of 80-100 bar.

from: http://en.wikipedia.org/wiki/Top_Fuel#Top_fuel_engines

 

No, Honda tried very hard to make it work, but finally gave up.
I guess they found out they got more problems than they were able to solve.
A.

 

Absolutely and the desmodromic actuator gives them also an advantage when downshifting, as they hardly blip the throttle, thus getting more engine braking effect without fear of valve floating.
A.

 

Yes, there was a NSR 750 road bike, I thought they ultimately gave up because the FIM closed the loop hole and banned oval pistons to stop people making "mock V8's" like the NR.