American race cars (formerly - OT: new car advice)

[Siri Amrit Kaur]

On Tuesday 22 November 2005 09:24 pm Mike Garfias kindly wrote:
> Robert N. Eaton spoke forth with the blessed manuscript:
> > At any rate, two valves of half the valve surface area weigh
> > about half of what one valve would weigh and would need lighter
> > valve springs. Less reciprocating weight equals higher rpm
> > without valve float, and that equals more power from a given
> > displacement engine.
>
> Two small valves weigh more than one single one.  A lot of the
> valve weight comes from the stem, not the face.  More power, less
> torque.  Torque actually moves things, HP is just a way to espress
> torque with reference to RPM.
>
> > Probably the most elegant answer to this problem was the one
> > devised by Ferrari a couple of years ago, when they set for
> > themselves the task of wringing 900 horsepower from a
> > V-10 twin cam multi-valved unblown three liter engine. They
> > figured that if they could get 300 hp out of a three liter engine
> > at 6000 rpm then they would have to spool up the engine to 18
> > grand to get 900 hp.  No known valve spring would survive that,
> > so they used 150 lbs of air pressure to close the valves. Air has
> > no natural frequency, so the valves could operate at this rate.
> > The only thing limiting the rpm was the reciprocating weight of
> > the pistons and connecting rods. These they had to fabricate from
> > titanium, at a cost that probably made even Ferrari blink. I
> > never found out whether they ever raced that engine, but what a
> > marvelous tour de force!
>
> Titanium is denser than Aluminum.  Thats why we use aluminum for
> pistons.  Ti is fine in the conrods, but doesn't make sense for the
> pistons. ---------------------------------------------------

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I have no clue about what you just said, but this is fascinating the 
hell out of me.

Siri Amrit
www.tigerflag.com