[Gasification] Producer Gas Engine Paper

[Rolf Uhle]

For a stepped compression change you just add copper washers under the change 
over plug.If you leave the spark plug in the injector' s hole, that action 
does not change so much this geometry factor.
If your spark plug is to be in the cast iron plug, than it receeds a bit with 
every washer, but i don' t think it makes much difference.
A bigger difference could come from a more central position inside the 
combustion chamber of a DI version. This divides the flame front lenght and 
eliminates the "shoot" out of the prechamber.
Some car manufacturers even top this by installing 2 sparkplugs opposite of 
each other in one cylhead.
Short flame front length can give you later timing and perhaps a more 
homogenious "explosion"
Swirl type cylheads and inlet pipes are helpful, too.

Wish you  nice and interesting summer holidays!

Rolf




Am Freitag, 1. Juli 2011 14:19:31 schrieb Ken Boak:
> Hi Rolf,
> 
> The Listeroid at APL is a JKSon Indian copy which is an Indirect Injection
> with the original Lister type pre-chamber head and a flat topped piston.
> 
> I have not tinkered with the pre-chamber form, other than adding a
> spark-plug into the cast iron plug, where the compression change-over valve
> would have fitted.
> 
> I was thinking of having some sort of arrangement like in a model
> compression ignition aero-engine, where the compression ratio could be
> varied with some sort of a movable "contra-piston" - but my machining
>  skills are not up to producing such a component.
> 
> I hope to make significant advances with woodgas trials on my Lister this
> summer.
> 
> 
> 
> Ken
> 
> On 1 July 2011 13:05, Rolf Uhle <energiesnaturals at gmx.de> wrote:
> > Hello Ken,
> >
> > it all relates to many factors, piston speed, head cavern design,piston
> > surface temp,timing of course,all versus flame propagation speed.
> > A small "normal" 1500/1800 or even 3000/3600 engine can very well have
> > slower
> > piston speeds than a big oldfashioned longstroke engine.
> >
> > By the way, have you ever tinkered with the prechamber form in your
> > Lister?
> >
> > Is Jim' s Listeroid DI ? Can' t ask him myself 'cause he doesn' t answer
> > me any more.
> >
> > salut
> >
> > Rolf
> >
> > Am Freitag, 1. Juli 2011 13:29:21 schrieb Ken Boak:
> > > This is an interesting discussion, which tends to make me believe that
> >
> > the
> >
> > > future of woodgas, will be ignited with the use of conventional diesel
> > > engines, modified for spark ignition, rather than the initially more
> > >  obvious choice of a gasoline engine.
> > >
> > > If, as suggested that woodgas can be used without knock problems in a
> >
> > stock
> >
> > > diesel engine at a compression ratio of 17:1, then this better than
> > > compensates for the loss of efficiency when used in a gasoline engine.
> > >
> > > As an enthusiastic user of the slow speed Lister type diesel engines, I
> > >  hope to be commencing some power tests on woodgas later this year.  It
> > >  will be interesting to see how  woodgas performs at the much slower
> > > 600 rpm of the Lister, compared to the more normal 1500/1800rpm of a
> > > direct drive diesel generator.  The Lister being an old design with a
> >
> > relatively
> >
> > >  long stroke of 5.5"  has a  mean piston speed of about 10 feet per
> >
> > second
> >
> > >  - how this relates to a modern, "squarer"  higher rpm engine I would
> >
> > need
> >
> > >  to
> > > investigate.
> > >
> > >
> > >
> > > Ken
> >
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