Engine for natural gas generator

[europachris]

Good points!  Furthermore, as long as you run some synthetic oil in it and keep the battery charged, you've got a high chance it's going to start when it's really cold, and not have to worry about it freezing up.

Air cooling abides by the K.I.S.S. principle!

Chris

[mobile_bob]

for backup power, the aircooled is probably ok, simple and not much fuss.
but you overall efficiency is going to suck big time, maybe 15% overall efficiency if you are lucky.

i would expect a small water cooled such as the changfa, would beat that by a factor of 3, if you use the hot water for domestic use.

bob g

[rcavictim]

Bob,

Do you have any experience trying to start a Changfa diesel in winter temperatures?

[mobile_bob]

not yet, but i have started early big cam 400 cummins with their sub 12:1 compression, and also 1693 cats at 20 degrees below 0 F. without glowplugs

i would bet i would not have any problem starting a changfa, at similar low temps with the use of a glow plug.

also if i was to live in a hostile environment,  i would place the engine in a well insulated shed, and use a large tank for cooling the engine, the holdover temp of the tank in a well insulated shed would go along way toward moderating the temperatures in the shed and the engine.

even gas engines, are a bitch to start at negative 20 degree temps

years ago cummins made a unit that in the intake had not only a large glow plug but a primer pump that would spray diesel over the glow plug in the intake as you were cranking the engine, the engine would intake fire and warm up for easier starting.

my bet is a 10 dollar glow plug out of a ford diesel (6.9 or 7.3) would be ample to heat the intake and make for a fairly easy start, especially if one used an electric start.

if you want 15 or 20 kwatt, just go find a thermo king diesel (isuzu) they are made to start in the harshest of climates, with windchill factors of perhaps 100 below!  just think how cold they get being pulled around at 70mph behind a truck in sub zero weather, stop, load and start the thermoking, when they are colder than a witches you know what in the klondike.

i dont mean to rain on your parade in regard to the vw or the corvair, but ..
the corvair is in short supply, and the vw is close behind for good runners
and both are a bitch to start in sub zero weather on gasoline, and the propane regulators freeze up real well when things are down below zero as well.

i used to do alot of service calls starting gas, diesel and propane fuel trucks in sub zero temps, of the three the diesel was the easiest to start if the fuel was not gelled. speaking of course to average condition engines, not new ones. new gas engines did better at starting but not alot better.

bob g

[mobile_bob]

btw,, i am regarded as being the "go to guy" for cold weather starting

things that can be used for cold starting, (below zero)

1. fire, a smudge pot made out of a cut off steel drum, filled with oil soaked rags, slid under the truck and set afire!
been there done that.

2. hot air from a space heater, works well

3. starting ether works well in moderation, if admitted to a cranking engine you won't lock it up and damage stuff

4. gasoline in a windex bottle to atomize the spray, works nearly as well as ether, with much lower chance of damage.

5. propane torch lit and stuck down the intake pipe as you crank the engine, will admit heat to the intake air and speed up starting.

6. glowplugs of course do a very good job, and i would not be afraid of installing two of them in a listeroid or a changfa if need be.

7. shelter for the engine is a big help, get it out of the  wind, and don't place the shed at the lowest part of the property, that is where the coldest air will settle.

8. insulate you shed, and build it of thermal mass if possible this well help to hold over a moderate temp for easy starting.

9. don't mount the engine to an uninsulated slab if you can keep from it, unisulated slabs are like heat magnets

10. a small shed can be kept above freezing with a 100 watt light bulb, as evidenced by many farmers in their water pump houses.

11. when starting a diesel, set the rack to no fuel (if you have the ability to do so) and crank it over several revolutions, this will allow the cylinder to build some heat before the fuel spray is admitted. fuel spray has a refigeration quality about it. then advance the throttle to fuel position. Detroit advised this method and it works for any engine that you have a cable pull engine shutdown.

just a few of my favorite things....

bob g

[Doug]

There used to be an old fellow here in the Nickel City that would start dead frozen iron by cutting into your heater hoses and running coolant into yur car/truck from his. "Hot Start" was on the side of his service truck and he made a good living repairing and starting cars and trucks around here.

One more things where hydro is available common sence with cars in trucks in the northland is a statnard block heater or inline unit. Suzuki used to provide an external heaterthe warn the side of the blocks in the SJ410 and i think my Firefly had one as well.

Before I would put a fire to the base of your Listeroid/Petteroid I'd look into mounting it on a steel frame and leave enough room between the foundation block and enging sump for something a little more refined like a propane heater, small turk burner or clean wood heater like a T-lud stove and be real sure I didn't burn the place down. CO is another issue with flame heat in an out building to consider....

Doug

[europachris]

Bob,

Do you have any experience trying to start a Changfa diesel in winter temperatures?

I cranked up my R185 one morning when it was maybe 50F and full of cold water.  It took a bit.  Lots of belching and farting.  Finally it took off and ran on it's own after several tries.  I'd not want to try starting one below 40F without some sort of preheat.

My backup plan for the winter time (in case power goes out) is to fill it from the hot water heater drain spigot (so I can tap water even if the well tank has no pressure).  Instant warm engine!  I store it dry, so there's no worry about the water in the hopper freezing.  Even just room temp (68F) water in the winter would make a big difference.

Chris

[aqmxv]

I'll agree that total efficiency isn't going to be wonderful with an air cooled engine.  Looks like the as-installed BSFC for Big deal.  It's backup power.  OTOH, if you persist in wanting to get full value out of your corvair generator, I'll point out that they make just fine car heaters...presumably perfectly good house heaters, too.  Back in the day we were all paranoid about the carbon monoxide possibilities.  Now, with battery-op CO meters everywhere, I canreport that a Corvair engine in good repair produces cooling air that is, in fact both odor and CO free.

Another upside to using something air cooled as backup power: (particulary if you keep the stock thermostat on a VW or Corvair) - fast warmup and stabilization.  Making 20-30 HP, a stationary vair will go from 30 F ambient to regulated head and oil temps in less than 10 minutes.  Try that with your tank-cooled changfa.

The coldest temp I've ever started a vair at was about -18 F.  It started fine, but was a bit dodgy for about 10 seconds until the heads warmed enough to deglaze the chambers.  This would probably not be an issue on methane.  Neither would oil dilution.  Things like Corvairs and VWs have a pretty easy time with cold starting because the engines are small, have low cranking effort, and the batteries (group 24 in a late vair) are generally sized for starting SB chevies and windsor fords.  I got eight years out of a diesel rabbit battery (type 41) in a daily-driver '69 beetle with stock charging system in PA.  I think the lowest cranking temp we saw was around -10 F.  It started immediately, in spite of that silly intake manifold VWs use.

Looking at the test report, best BSFC at 1800 RPM is going to be about .49  lb/hp-hr at about 35 HP.  Believe it or not, the minimum full-throttle BSFC for the 110 HP corvair (very similar to the 102 I'm recommending) is .522 lb/hp-hr @ 2000 RPM (pulse enrichment in the carburetor gives the higher number at full power)...  You're quite close to the sweet spot with an 1800 RPM generator.

Is it wonderful?  No.  But it is: 1) cheap, 2) runs on methane (stated requirement) 3) will direct-drive a 20KW ST 1800 RPM head without fuss, 4) simple 5) not fussy 6) copes with cold starts and short run cycles well.  You could even wire it to pushbutton start from the house, if you wanted, and then throw the transfer switch.

[mobile_bob]

points well taken

what does a good corvair engine or vw engine go for in dollars?
what i mean by a good one is one that is ready to use, and not something that needs work.

i would be surprised if a good runner corvair would go for less than 1500 bucks these days, but could be wrong
wouldnt a vw bring a grand?

a good running c201 TK can be had for about 500-750 bucks, and they have the remote panel to take into the house already. and are dual rpm engines, high and low speed settings switchable from the control panel

as far as methane or propane is concerned the c201 will handle that easily in dual fuel mode, i would think.

just curious

bob g

[Procrustes]

I agree a Corvair or VW engine might be better.  They seem pricier though.

I'm seeing complete or nearly complete Ford 200, 250, and 300 i-6's and Chrysler slant sixes for a couple hundred dollars, purportedly good runners.  Ring kits are $150, complete rebuild kits $450, in very round figures.

Does anyone have any advice on an engine controller?  I believe all I have to have is an rpm sensor and throttle actuator.  Most of the kits I can find are hundreds of dollars.  Some features I've seen are over/under voltage cutouts, engine over/under speed cutouts, overheat, low oil, grid tie, you name it.  These guys look helpful: http://www.governors-america.com/.  I'll get on the phone with them on Monday.

I don't worry any more about carbon monoxide.  I have a grill on my deck, and if I leave a window open and the breeze blows right, all my fire alarms go off, even the ones upstairs.

[rcavictim]

Does anyone have any advice on an engine controller?  I believe all I have to have is an rpm sensor and throttle actuator. 

Try http://www.thepiercecompany.com/html/pulley_driven.html

These folks have a nice universal pulley driven governor that will take control of your engine`s throttle foir a good price.  I found a similar unit off an old Hobart welder for my own VW diesel genset project.

[fuddyduddy]

There are many aftermarket auto cruise controls that use a magnetic driveline sensor.

If you are going to retain the electric starter for your engine, and alternator, battery, etc,  you will have the DC power necessary to operate the cruise control.

Cheap, simple, and effective.

[Procrustes]

a good running c201 TK can be had for about 500-750 bucks, and they have the remote panel to take into the house already. and are dual rpm engines, high and low speed settings switchable from the control panel

as far as methane or propane is concerned the c201 will handle that easily in dual fuel mode, i would think.

That is a good idea.  I might well end up saving money and grief since it comes with a governor.  What do you mean by a dual fuel mode for the c201?  Is it set up to support a carburetor?

[Procrustes]

Try http://www.thepiercecompany.com/html/pulley_driven.html

That looks perfect.  Thanks for the link.

Did you have much trouble fabricating an armature for your VW?

[Doug]

a good running c201 TK can be had for about 500-750 bucks, and they have the remote panel to take into the house already. and are dual rpm engines, high and low speed settings switchable from the control panel

as far as methane or propane is concerned the c201 will handle that easily in dual fuel mode, i would think.

That is a good idea.  I might well end up saving money and grief since it comes with a governor.  What do you mean by a dual fuel mode for the c201?  Is it set up to support a carburetor?

What Bob means by dual fuel mode is using the fuel injector to squirt a small amount of Pilot fuel to ignite the natural gas rather than a spark plug. I'm no expert in this area and have never seen exactly how it done. There is some evidience that engines running this way give a longer service life. Some aplication need an air oiler for the top end of the liner and rings. Some aplications need an injector change because at low fuel flow levels the injectors or the tips may coke and or overheat, the injector bleed off line may need to be rerouted back to tank instead to ensure enough cool fuel is cerculating to cool the pump and injector ect ect ect.

I only know what I read and never have seen this done.

And yes a carburator may be needed or the gas fuel might be injected depending on the aplication

Doug