Ferrari V8 smoother than big American V8?

Welcome to Ferrari Chat Grummer - you haven't made a fool of yourself! I am also curious to know this - Ferrari V8 engines do have a smoother sound than American V8 engines.

 

I posted a thread on this a few weeks ago. There is a paragraph that helps explain the smoothness perceived: Ferrari changes its tune | The Economist

It is a good read! Enjoy.

 

I don't know the answer to your specific question but a V8 is not a naturally balanced engine so whether it's a cross or flat plane it's still going to be shaky without counterbalances.

The flat plane has some different balance issues than the cross plane but it's hard to design one larger than 4.5 liters, as a result. I think newer technology made it possible for Ford but now with turbos becoming mainstream they'll downsize again.

 

A couple of points:

A) a flat plane crank has about 3X the vibration energy as a cross plane crank in a 90 degree V8.

B) the vibrations go up as the square of engine capacity
C) the vibrations go up cubically with RPMs.

Thus, a small FP V8 can produce lower actual vibration levels than a big CP V8 running slower.

However, when of equal size and equal capacity, the FP always has more vibrations.

D) Ferrari goes to more trouble balancing the components in their engines than the normal Big V8 guys do.

 

What I'd like to know is why haven't any mainstream manufacturers built engines like Ferrari? Seems it'd be a surefire way to boost sales. I'd much rather own a Corvette/BMW/xxx that sounded like a Ferrari than just the old, big block 'blub, blub, blub'.

 

This question has been raised before ie the new Mustang GT350/R and why it does not sound like a Ferrari, use the search option.

A FP crank has less reciprocating mass thus needs to achieve a higher rpm for max torque unlike the norm crank in those "blub, blub, blub" POS's. Do you prefer max torque from 5-6Krpm or from 1500 to 5000rpm? Ask Sheldon.

 

An "American" V8 can certainly have a lumpy, rough idle when hot rodded with long duration cams. But in ordinary applications, they are definitely smoother. Perceptions can vary depending on how spongy the engine mounts are as well. I'm not sure about 355s, but in 430s, they use harder bushings in the coupe. The motor can definitely be felt in my 430. It is my understanding that flat cranks have better response and are better suited for high rpm operation. Ford is now using flat cranks in one of its hi-po mustang motors.

Dave

 

A balanced and blueprinted 350 chevrolet motor with the right cam is smooth.

 

Untill recently, I owned a Bristol 411 s5.
It has a 402 cu inch Chrysler engine. It ran quite smoothly untouched, but ran like a dream after a complete rebuilt using Edelbrock components together with balancing.

Used to own a modern Jag XJ with a V8. Smooth.

I guess it is more the precision in the design and assembly that results in a smooth running V8 at the end.

 

I laugh when I read stuff like this. They have a different character, for sure, but cross-plane V8's, even the American push-rod variety, have their place and can be very potent and very fun. The current generation of GM push-rod V8's is amazingly size and weight efficient for the power and torque they make. The LS7 that was in the previous gen corvette is one the neatest engines ever IMHO. I drove one back to back against a 997.1 GT3 and F430 last year and thought it compared very well - totally different in character, but to me that was part of its appeal. Ideally you'd have all 3....

 

There is smoothness of the engine but there is also the "smoothness" in the firing order.

The firing order in American V8's is not as orderly and evenly spaced as the firing order of a flat plane engine. That is why the sound of an American V8 is rougher and more a collection of sounds whereas the sound of a Ferrari engine is smoother, more orderly, more precise sounding.

So in conclusion, there is how an engine feels but also how it sounds.

-F

 

This does sound awesome on an idling Donzi.

 

Ford has changed the character of American V8s with its new flat-plane crank V8 that is utilized by the new Mustang Shelby cars.

I don't think it sounds like a Ferrari, but it is certainly different from traditional Ford V8s for sure.

 

As long as you realize I was only repeating what was previously said.

 

and at full chat...a sound to covet!!! we are all car guys and bad azz is simply bad azz

 

The cross plane arrangement gives the potential for balancing both first order and second order forces resulting from the movement of the reciprocating elements around the crankshaft centerline. The flat plane arrangement Ferarri uses is like two 4 cylinder engines joined at the crankshaft (which in turn is a little diferent from what Ford uses on the new GT-350) where only the primary forces can be counterbalanced, leaving behind the secondary forces. In one way this benefits the FP as compared to CP arrangement by allowing smaller and lighter counterweights for primary balance as compared to heavier counterweighting used to achieve balance in the CP. In the CP, the greater rotating mass is traded for improved balance and "smoothness", in principle.

So the FP should, everything else equal, be able to change momentum state more rapidly ( rev more quickly) then the CP. The firing order is also quite different in that a typical CP fires two cylinders on the same bank of the vee back to back twice in the firing order where this does not happen in the FP firing order. I am told this accounts for the CP burble versus the syncopated beat of the FP. I also understand FP engine mount design is different in order to dampen some of the vibration. There is a difference in both vibrational and sonic signature.

All that said, there are lot's of variables in play regarding "smoothness". After many years of both pushrod and overhead cam CP's (all street engines), I suppose I notice a little bit of a different vibration at idle in my 430 by comparison. But nothing of the sort when the engine is on song. Or I'm just distracted by the distinct and in my opinion intoxicating sound around me!

 

Lots of stuff on the internet about crank balance.

https://en.wikipedia.org/wiki/Engine_balance
https://www.physicsforums.com/threads/crankshaft-balance.746803/
Flat Plane Cranks... Why? - The Technical Forum Archive - The AUTOSPORT Forums

(Although most of the cranks around here are a bit unbalanced. )

 

I believe the Ford FP engine has balance shafts?

 

I don't think so

 

It all goes by what you prefer, I just came from the Corvette side. Ferrari is more elegant, a more pleasant sounding hum. The American V8s are more rough and violent sounding