In my history as a valet driver, I have parked several high-end automobiles, including those with V12 engines: Mercedes Benz, Jaguar, Ferrari, Lamborghini.
Now, I’ve started straight fours and sixes, V6, V8 and even the V10 in the Dodge Viper, and they all sound similar before ignition catches in the cylinder:
RR-RR-RR-RR-RR
But a V12 (60 degrees?) has a smooth zzZZZZIP! when starting.
What is it about the firing pattern that the starter motor likes so much?
Maybe becuase the starter has less work to do before the engine catches. ie, less to turn the flywheel before the first cylinder fires (on average anyways), assuming it dosen’t turn over on the first cylinder, less distance until the next and so on. But that’s just my WAG.
It’s partly the number of cylinders (more = smoother), and partly the balance of 6/12 cylinder engines.
In-line 6’s have an inherent balance and smoothness that is lacking in 4’s, 5’s, L-8’s, V-8’s, and V-10’s. V-12’s are essentially two L-6’s blended together so as to stagger their power pulses, which makes the running smoother yet.
Sheesh, I’m just too jealous to give an answer, even if I had one.
Mayybe its a combination of a high-torque starter and lower gear ratio (starter to flywheel)…
If you watch a funny car start up you’ll notice a high pitched ::zzzzipp::RUMBLE:::
Lower gear=higher pitch no?
My WAG
Wat FranticMad said 
Oops, that was supposed to be a “What…”!
How do you go about getting a job as a valet driver? It sounds like a pretty good deal. Do the hotels have to advertise for them or what? I want in on this action.
Have you started V-12s from different manufactures?
Ferrari…Jaguar…BMW, etc?
Just curious. Some European cars have a different start up than American cars because of the type of starter used.
V-12s get ignition faster, and many v-12 are not much larger than Detroit V-8s. Like a 5.0 liter V-12 will be silky versus a 5.8 liter
v-8.
A 2.5 litre four will rumble, because 2.5 liters is quite big for just four cylinders…each piston is quite large.
Usually, many cylinders and small engine size = pure butter and quick response.
Oh- most v-10s from Detroit are monsters in terms of displacement. Much bigger than v-12s. Not uncommon to come across a 7 litre v-10, and makes for a longer rougher start.
To get a job as a valet driver, you have to put in job applications at the casinos…keep your eyes open for the want ads in The Press, the major newspaper in the South Jersey area.
You have to be at least 18, drive a stick-shift, and have a clean driving record.
I have to agree with Gary T’s assesment of inline sixes. I had a BMW with a 2.5l six that was the smoothest I’ve seen through the whole RPM range, at least until the rev limiter cut in. I also had a '64 Dodge pickup with a 225 slant six but… it was somewhat less smmooth.
Ok, I’ll ask.
Is a “valet driver” one of those folks who park cars? And why would anyone want to do that?
Peace,
mangeorge