[Vwdiesel] Heads up (fwd)

[pmdolan at sasktel.net]

Adiabatic engines have been around a long time - in lab form only.  I am not aware of ANY commercial production that has ever taken place (please, someone provide a source and correct me if I am wrong).  I think Cummins are closer than anyone else to having a practical, all-ceramic surface (no lube), adiabatic (no coolant) engine, but it is a lab curiosity, not yet economically possible for production.

Anything powered by Briggs and Scrap Iron would not tempt me to buy a piece of equipment that has to have a long life cycle.  I suppose it is vaguely POSSIBLE that they could make a decent engine, I have never seen anything that is even remotely close to Chinese quality, never mind Euro or Japanese.  If they were to have used ceramics, I am certain it was limited to very few surfaces, since I don't remember it ever being news in either the materials science or engineering literature of the day.

Big, Diesel cycle gensets and big compressors normally run for  decades without major maintenance.  Even the tiny 25kW portables normally see 15,000++ hours between overhauls (modern aircraft piston engines are very lucky to get past 2,500). The secret of great themal efficiency is to use a relatively low speed engine, exploit the constant pressure possible on the long, slow power stroke, and allow some extra time after the end of injection event for the cylinder to more completely expand the gasses (i.e. keep EGT very low).  Stationary engines (and to some extent marine engines) are well suited to doing this kind of thing.  Diesels are just plain amazingly good technology for prime movers, and I agree that going to ceramic bores and pistons may well take them the next step further.  It's just that that step is not likely going to happen for a few years yet (cost issues).

----- Original Message -----
From: Val Christian <val at mongobird.com>
Date: Tuesday, December 26, 2006 7:24 am
Subject: Re: [Vwdiesel] Heads up (fwd)

> About 10 or 15 years ago, York, the PA based HVAC company, had a 
> residential heatpump offering that was an air source heatpump,
> with the compressor powered by an Otto cycle one banger. The 
> engine was advertised as being a ceramic, although I don't know 
> how much ceramic.  
> 
> The idea was that it ran the compressor, which accounts for the 
> majority of energy consumed by a heat pump.  Running on natural 
> gas caused it to have a lower unit energy price.  Additionally, 
> in the wintertime, waste heat from the engine was used to augment
> the heat source.  I believe it also had some kind of NG powered
> heat capability for extreme cold.
> 
> At the time, I looked into one of these, although my existing 
> air source HP was not old enough to justify replcement.  I recall
> that the engine was manufactured by Briggs and Stratton.  The 
> maintenance schedule was a 1qt oil change every year.  As I recall,
> under heavy usage the spark plugs sometimes needed replacement 
> before the oil.
> 
> About 5 years after offering this unit, it was discontinued.  Probably
> a good thing I never got one, as maintaining an orphaned unit
> can be frustrating and expensive.  I asked the local distributor
> when it was discontinued if there were problems.  By their accounting,
> it had few problems, except that sales never really took off.
> As I recall, we were also into the cycle of "cheap" energy.
> 
> I wonder if Briggs makes this engine for other applications.
> 
> BTW, relative to heating, when I bought my first Diesel Rabbit (1976),
> one of the mechanics at work was telling me about his experience
> with the diesel generator on the family hotel in Alaska.  Apparently
> they had a big one-banger diesel generator, with a huge flywheel.
> They used it for over 20 years.  The couple of times they had to 
> shut it down, required a unique starting process.  They would take
> a dumptruck, and position a rear wheel to have friction contact
> with the flywheel.  With jacks and blocking on the other wheels, the
> dumptruck would start the flywheel spinning, and then someone 
> would turn on the fuel.  The wheels would be unblocked, and the 
> truck (aka starter) would drive away.  The diesel heated their
> water at the hotel, and supplied electricity.
> 
> Val
> 
> 
> 
> 
> Forwarded message:
> > 
> > Gm did the same testing in 1979 thru 1981, the results were very 
> good, 
> > very cool running, used no oil for lubricant, no rings for the 
> pistons. 
> > Cost was the reason GM scrapped the program, or so my dad told 
> me, he 
> > had worked on the project.
> > On Dec 25, 2006, at 2:40 PM, Andrew Buc wrote:
> > 
> > > On Dec 24, 2006, at 11:10 PM, James Hansen wrote:
> > >
> > >> Ideally, a ceramic head, if you could seal it, would
> > >> kick butt because you could let it glow red, and it would be 
> no big
> > >> deal.
> > >>
> > >
> > >
> > > Some years ago a Japanese company (possibly Mitsubishi, but I 
> could> > be wrong) built some experimental all-ceramic engines. 
> Great thermal
> > > efficiency, no need for a cooling system.
> 
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