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Re: Bore/Stroke Ratio

To: ardunbill@webtv.net, List Land Speed <land-speed@autox.team.net>
Subject: Re: Bore/Stroke Ratio
From: "Bryan A. Savage Jr" <basavage@earthlink.net>
Date: Fri, 20 Oct 2000 08:36:41 -0700
Apparently there is a point of diminishing returns. 
Yamaha's latest 1000 cc, the R1, has decreased the bore several 
millimeters to improve combustion chamber efficiency by reducing
flame front travel. 
According to Rick Gold, detonation is not a problem in F-1
17,000 RPM motors, getting the gas to burn fast enough so that the 
piston doesn't out run the flame front is a problem. The stuff
they call gasoline would test around 85-90 octane. 
This is never never land stuff to me, but interesting....

Bryan Savage


ardunbill@webtv.net wrote:
> 
> In the motorcycle racing world, there is a continuing trend to
> ever-shorter strokes nowadays, since the shorter the stroke, the lower
> the piston speed, and the higher the revs without excessive piston
> speed, the higher the horsepower.  Big bores also allow bigger valves,
> but on the other hand, the bigger the bore, the greater the tendency to
> detonation.  According to the authorities I read.  Always a lot of ifs,
> ands and buts about it.
> 
> Cheers from ArdunBill in the Great Dismal Swamp, Chesapeake, VA

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