In a message dated 09/07/2004 3:49:31 PM Pacific Standard Time,
rick@stoolhead.com writes:
> the
> original Lamborghini Countach (the LP400; before they put scoops and
> wings all over it -- just a simple wedge shape; as radical a design
> statement as Figoni Falaschi were half a century earlier),
Yes. Rode in one last spring. I have to exclaim, and I have been in MANY
exotic cars, that the LP400 sounds better than ANY other car I have ever
experienced. There is just something special about a flat (boxer) twelve
with SIX 48DCOEs! The exhaust is great. The roar of the Webers is beyond
awesome.
____________________
Well actually it is not a flat engine - it is a 60 deg. V-12.
And the carbs are 45 DCOE, although they used 40 DCOE on earlier engines
with no loss - remember that we are talking about a 3929 cc engine, so each
cylinder is only 327 cc, in other words it would be the size of a Mini if it
were
a 4 cylinder, or a GT-6 if it were a 6 cylinder. Thus 40 DCOE is the right
spec for it. Oddly enough, they go into the intake ports which are located
between the cams on each bank - because it is a narrow angle V there is no room
in the centre between the intake cams as some of the Ferraris do.
It is essentially 2 straight 6 cylinder engines on a common crank. Each bank
(on my car) has a completely separate ignition system, with a 6 cylinder
distributor running each side. You can end up with one bank advanced over the
other, if you don't set it up right.
The effort to pull 12 throttles open is significant - it was a lot of fun to
hold at 1000 rpm for its smog test as to raise it a bit, you press until you
overcome friction and then it blips up too far, so you let off and it drops
too far, and.......
Although each cylinder is only 3/4 the size of one MGB cylinder, the pistons
are bigger at 82 mm, and the stroke is very short at 62 mm (vs. 89 on the
MG), which is what allows it to rev to 8000.
I haven't had the jam to run it over 7000, but that's enough to get the
right sound.
BTW - the somewhat agricultural MGB engine (I'm talking about the early 60s
best version, not the rather pathetic later editions) has a torque peak at
3500 RPM and a power peak at 5400 RPM.
In comparison, the Lamborghini has a torque peak at 5500 RPM, and a power
peak at 7700 RPM. That, and the flexibility to floor it in 5th gear at 1000 RPM
(idle) and have it pick up smoothly all the way to theoretical redline at
around 165 mph makes this uniquely flexible, at least in my experience.
The MGA Twincam had a torque peak at 4500 and a power peak at 6700 RPM,
pretty damned respectable for such a long stroker, and even my Twincam race car
only peaks about 500 RPM above that.
Bill
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