Ferrari engine note

How = Because they have "alternate bank firing" (L-R-L-R-L-R...), which makes the time between exhaust pulse arrivals in each exhaust manifold the same and produces a very "clean" single primary tone -- and a lot of cylinders

Why = best peak torque -- and it sounds great

 

Do you have any more information on this? a webpage regarding the topic? I'm very interested in learning more about this.

 

Ferrari also uses flat-plane crankshafts in its V-8 models. This results in a unique sound.

 

And if I may sneak in two related questions: how much of the Ferrari sound is due to the design and layout of the exhaust system; and in carburetted cars, do the carbs contribute to the overall note as well?

 

For what it is worth, and IMHO...

Yes on both (i.e. - quite a lot of the V12 sound is the exhaust, and the carbs have that vacuum sound...). Did you ever listen to one of those V12 Jaguar, Mercedes, or BMW sedans? Nothing at all like a Ferrari - although the Aston Martin kind of has a little of it.

The carbs, yes, but a thing of the past now except for the millionaires. The deal, I think, was the multiple small throats versus say a big 3/4-throat Holley. At least until the Holley gets that secondary open, and then it has something all it's own.

I have never warmed up to the flat-plane V8s, though. Too much "buzz" to suit me when driving - but they sound good from the curbside.

IMHO, this is one of the fundamental things that makes a sports car great - that is, it's own unique sound due to primary engineering features. I bought both the TR and the ZR1 a lot on the sound feature. It is rumored that Porsche went to a lot of trouble to replicate some the the "air-cooled" sound with their water cooled boxer generation.

I don't think they were entirely successful, though.

James

 

Wasn't the 360 the first v-8 with the flat-plane crank?

 

Thank you. I have yet to hear a carbed Ferrari!

 

Nope, that's a feature from the 3.0 V8 forward

 

A flat crankshaft in a 90 deg V8 block is just one physical configuration that gives alternate bank firing -- the vintage F V12 and F flat12 also have alternate bank firing, but they don't use flat crankshafts.

It's not really "carbs" that make the inlet noise sound sweet -- it's the number of inlets and amount of attenuation from the air filtration system. I.e., best inlet sound = V12 with one throttle plate per cylinder and short open velocity stacks. BBi and TR don't sound as good because they only have one throttle plate for 6 cylinders and a real air filter .

Is 360 first 90 deg V8 with a flat crank? = no way. My guess would be something in the 1920s or 1930s (like 4 valves per cylinder), but maybe 308 would qualify as the first mass-produced sports car to have one.

 

++ on the air filters, a big part of the equation. Most manufacturers try to dampen out this sound, while older Ferraris seemed to glorify it.

I read somewhere that Ferrari did the "alternate bank" thing as much for structural engineering tradition as for power or sound...it said that the Ferrari designers like to use rods mounted in pairs on the crankshaft rather than individual throws for each cylinder. Maybe this also had to do with engine length, crankshaft strength, main bearing position, etc.

OK, found part of it- the guy says the first Ferrari v8 was a 1964 formula one car, type 158, driven by John Surtees. Even the so-called "Boxer" 12 cyl cars apparantly all had this "paired rod" design - so they were not really boxers after all, like a Porsche.

James

 

May be a silly question, but how much of it is because of the muffler used?


Can the sound be partially replicated using a high-tech muffler, say, on a non-Ferrari?

 

Depends on the "non-Ferrari" in question. If its engine is somewhat similar to a Ferrari engine, yes. If it's a 1.4 litre Honda: No way. The muffler can only alter the sound coming from its "input", it can not reproduce another one. A small engine always stays a small engine, something the ricer kiddies (...and, here in our beautiful Bavaria, the VW Golf and Opel Corsa guys) will never understand.

 

A lot has to do with the flat crank. If you listen, the V8 sounds more like a sport bike (except a fuller sound). It's not just the small displacement or the high rpms. My RS4 will spool up to 8k and sounds awesome, but nothing like a 355. Unfortunately, there is no substitute!

BTW, the 355 and 348 definitely have the flat plane crank. Not sure about the 308/328.

 

I agree with Tillman, all of the V8s all the way back to the 308GT4 had the so-called "flat" crank. They are not really "flat" in the truest geometric sense, it means they only have the two planes due to the rods being paired on single crank throws rather than an individual throw per cylinder.

 

Close but not quite. Most (all?) V4/6/8/10/12/16 engines pair opposite cylinder rods on a common crank pin. The V8 flat plane crank has 2 crank pins each at 0* and 180*, thus a single line will bisect both throws and the mains, thus all on one plane. The American cross plane V8 crank has one pin each at 0*, 90*, 180* and 270*. A single line would not intersect all the throws.

http://en.wikipedia.org/wiki/V8_engine

 

With the Dino's, of which I have one, I think the 246's have a very low frequency blat sound something like the older Porches. I have a 206 with a small diameter four pipe exhaust that IMHO has a wonderful, higher frequency, sound, along with all the neat mechanical noises. It's a lot different from the 246's. Not just my opinion as other folks have mentioned it as well. Essentially the same engine, just a bit smaller. Only thing I can think of is the exhaust muffler, don't know about the in's and out's of firing times, just my opinion of course.

 

The Jaguar V12 quad Stromberg is a totally different animal. It is completely subdued for idle quality and smoothness. It's an air restricted undersquare design to maximize low end torque. With some minor modifications and custom exhaust fitted from a 90's Jag, you FEEL it, not hear it. It revs nice and smooth up to 7,500rpm like a turbine, not a performance engine. It requires constant tweaking and tuning that the FI V12 made far simpler.

 

An american V8 with a cross-plane crank doesn't fire alternate banks consistently. The firing order means that you sometimes get successive exhaust pulses into the same manifold. In a dual exhaust, this means inconsistent pressure pulses in the two sides.

Look up "beat frequency". When you have two frequencies that are almost -- but not quite -- the same, the difference causes a low frequency pulsation (beat frequency) that gives the american muscle car its distinctive low frequency rumble.

The same thing happens in twin engine aircraft when you don't "synchronize" your props -- the rpm difference between the two props makes for a low frequency throb you can feel as an intermittant vibration.

With pure alternate bank firing, the Ferrari engines have identical pressure pulse rates into both exhaust manifolds, so the exhausts are "synchronized". After that, it's just a matter of tuning the exhaust paths.

So, no, a Ferrari type exhaust on a cross-crank engine will not replicate the Ferrari exhaust note.

Some newer GM V8 engines have cross-connections between the exhaust sides to reduce the exhaust "rumble". But many modern cars combine the exhausts before the catalytic converter(s), anyway, so the era of the pure "dual exhaust" is pretty much gone.

 

There are two types of V8s which differ by crankshaft. The V-angle is always 90°. The two types are called cross-plane (crank pins at a 90° angle) and flat-plane (crank pins at 180°). V8 engines have the advantage of not being in need of split crank pins in order to avoid vibrations between cylinder banks.
With a cross-plane V8, however, the last cylinder is not in the same position as the first, so there is end-to-end vibration again. That can be solved by adding counterweights to the crankshaft which cancel the forced created by the pistons. That is possible only in a V-engine with a V-angle of 90° and without splitted crank pins. These counterweights, fitted to an inline engine, would move to the side when the piston moves up or down and therefore generate additional vibration. But in a 90° V-engine there are pistons on the same crank pin which move exactly into the opposite directions of the counterweights (because of the bank angle) and their forces can be cancelled. Cross-plane V8s are therefore running quite smooth but because of the heavier crankshaft they are not as revvy.

Flat-plane V8 engines do not have those problems. They are also more responsive because of less rotational inertia. That increases maximum rpm and top-end power. In addition the crank case can be smaller which lowers the center of gravity.
But why are the flat-plane engines used in sports cars only if there are so many advantages? That's because of the crankshaft itself, the disadvantage of the flat-plane type. As you can see, the arrangement of crank pins is identical to a four cylinder engine which means there are also vibrations, only stronger, as basically two inline-four engines are running simultaneously. In sports cars those vibrations are reduced by using very lightweight pistons and connecting rods. That is of course expensive and because ride quality isn't too important either, the rough characteristics (compared to a cross-plane) are tolerated. Because of the crankshaft, the sound of such an engine is the one of two four cylinder engines. A (typical american) cross-plane burbling cannot be achieved.
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for comparison, a V-12...

The V12 is said to be the most sophisticated engine design, being free of vibrations and running smoothly. But so does an inline six. Now what is the difference between those two concepts concerning smoothness, as even the crankshafts look alike?
Let us return to the one-cylinder. It was said there, that an engine's power delivery occurs in 'jerks', every time a combustion takes place. And that is the secret of a V12: the smoothness is increased by more combustions per crankshaft revolution.
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