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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