Larry Widmer's "Soft head" swirl technology

[Andrew W. Macfadyen]

Air swirl is more than a theory  modern 4 valve per cylinder  DOHC
engines such as the Rover K series are built on the model of the
Cosworth FVA/DFV/BDA which was along with the old F1 Weslake V12 one of
the first engines to use a narrow valve included angle  to induce swirl
about a horizontal axis parrallel to the crankshaft. Because of the head
layout a very high energy swirl can be created which remains ordered.
Earlier head designs mainly on pushrod engines tried to create swirl
about a vertical axis were not really successful as not only did the
means used to create the swirl (usually offsetting the ports center line
from the valves) introduce restrictions on the gas flow but the swirl
induced quickly became chaotic and disperessed long before combustion
started.
The change in valve included angle was the main factor which makes 4
valve head viable prior to that good 2 valve dohc race engine  would
only be about 2 percent down on horsepower when compared to a  4 valve
engine, for proof look at the power figures for the last few years of
the old 1.5 litre Grand Prix cars back in the 60s in particular the 2
and 4 valve per cylinder version of the Coventry Climax V8.
The only way of getting a big speed up combustion in 2 valve engine is
to use squish (and reverse squish) using a May combustion chamber such
as used in the HE version of the Jag V12 and the ancient  Cosworth MAE
1000 cc engine.

Frank/G.speed wrote:

> Has anybody tried the techniques and theories of high swirl air
> into combustion champer (by the way of porting techniques and
> piston chamber design?  Larry is suppose to have achived BSFC's
> below .400, exhaust temps 1000F and even lower while maintaining
> power output because these motors are much more efficient.
>
> I know lot of very knowledgable people are on the list.  If you
> guys know who Larry is...  email is fine.
>
> How many of you weld up combustion chambers/ports to reshape them?
>
> --
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