Hi Craig
On (11 Aug 97) Craig Healy wrote to Alec Cameron...
 CH> Re: Low RPM, high torgue engine for cogeneration.
I baulk at the cogeneration bit. The interesting rig you describe is liable 
o
be unprofitable to you, a good citizen helping the utility Co.
 CH> The key is shaft HP.  No idea how the manufacturers rate these.
The elec output [kW] of the alternator is a good guide. Elec machines can be
fairly precisely calculated and measured re their losses- windage, friction,
copper loss, iron loss. Polytechnic and uni students often have to do this in
lab. as a curriculum requirement. I did!!
Many engine labs USE a "calibrated" generator as the method to determine
shaft HP. Others use a dynamometer.
 And
 CH> what the efficiency is, who knows?
Well the effy is vital so you don't go broke selling your kwHr too cheaply.
-> CH> I have often considered using a V-8 automotive engine with much
-> CH> altered cam and ignition timing running at 540 RPM (PTO speed)
-> CH> to run a generator.  By careful selection of components, it
-> CH> would probably be made to be quite efficient at that speed.
-> CH> Maybe even run it off piped-in natural gas for co-generation.
Do you think you have the necessary skill and other resources to make much
alteration to cam [?profiles] and ig timing? Wouldn't the auto advance be a
dodgy problem since at constant rpm the centrifugal feature would be
inoperable. If you fiddle with say three different cam changes and three
alternative ign settings then there are 3x2 ie six set ups that might be
tested in order to pick an OK one. Cancel your vacation away!!
 CH> not proposing that .  I was thinking about a standard synchronous
 CH> AC generator, sized appropriately.
Hey! Is there such a thing? I fear that you will have a very limited access 
o
any "standard" synch generator. To any enquiry you might find just a dozen,
all weird!!
 CH> turned.  To see if the project is practical.  So far, there has been
 CH> some opinions offered by folks with some good experience in the
 CH> field.  But I don't believe anyone has actually tried this.
They sure have tried it with induction generators. But you need the utility 
o
be agreeable because at many locations, this simple system depresses the
supply voltage while spinning the meters backwards.
 CH> I have been working with high-performance engines for 30+ years.
 CH> There is a tremendous body of work in improving efficiency in the
 CH> field.
If that all means state- of- the- art then I guess you would accept the need
to give close attention to mothering the setup. Most folk would rather leave 

basic commonplace cheap engine just run itself into oblivion then replace it.
A fun hobby doesn't have to be cheap!    Cheers..ALEC
... ........The best carpenters make the least chips
--- PPoint 1.92
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