Larry Widmer's "Soft head" swirl technology

[Kurek, Larry]

FWIW, I just received my August (?) issue of Hot Rod, and it has an
article on the new Mopar Magnum series heads. Funny this thread should
start....because one of the sidebars mentions the work of Larry Widmer
in indy cars. Hor Rod then put a reference in to one if its back issues,
July 1985, to an article titled "Soft Head Technology".  How did this
thread start again????

BTW...Bruce, I'll hopefully scan those ECM pinouts this
week/weekend...was somewhat busy this one.

TTYL!

Larry Kurek

> -----Original Message-----
> From:	Andrew W. Macfadyen [SMTP:am018 at post.almac.co.uk]
> Sent:	Monday, June 29, 1998 2:04 PM
> To:	diy_efi at efi332.eng.ohio-state.edu
> Subject:	Re: Larry Widmer's "Soft head" swirl technology
> 
> Swirl is a general Fluid-Dynamic term used in all sorts of flow
> situations
> it was first used in connection with combustion chamber design way
> back
> around the time of WW1, certainly Sir Harry Ricardo used to describe
> both
> the rotational flow induced by the inlet port design and that induced
> within
> the cylinder by "squish".
> The term "tumble-swirl" has been used to describe the flow in modern
> narrow
> valve included angle engines in several technical publications and is
> quite
> descriptive of the type of flow however I have until now never seen
> term
> tumble used on its own for this type of flow. All that the combustion
> process sees is the degree of mixing it cares not wether it is swirl
> or
> tumble-swirl or squish.
> Just how big a difference it can make was underlined to me about 20
> years
> back while racing 1000 saloon cars and I saw just how much adavance
> (43
> crank deg) the Coventry-Climax inspired  Rootes/Chrysler Imp engine
> required
> compared to the  Cosworth-Ford  MAE engine.
> 
> Dave Williams wrote:
> 
> > -> the first engines to use a narrow valve included angle  to induce
> > -> swirl about a horizontal axis parrallel to the crankshaft.
> Because of
> >
> >  Normally (at least on this side of the pond) "swirl" refers to
> motion
> > parallel to the cylinder axis; "tumble" refers to motion parallel to
> the
> > crankshaft axis.
> >
> >  Narrow-included-angle four valve heads are usually very good at
> tumble
> > and poor at swirl unless something is done with the valve timing or
> > shape of one of the intake ports.  Some engines use valves or
> deflectors
> > of various sorts in one port to induce swirl.
> >
> >
> ==dave.williams at chaos.lrk.ar.us======================================
> > I've got a secret / I've been hiding / under my skin / | Who are
> you?
> > my heart is human / my blood is boiling / my brain IBM |   who, who?
> > ===================================
> http://home1.gte.net/42/index.htm
> 
> 
> 
>