Should we consider LP and Nat. Gas CHP systems instead of diesel?

[BioHazard]

On another board I visit there is a guy who cast a custom water cooled block for the Briggs flathead engines for go kart racing. He said he spent over $10,000 in the process. He only ended up making one before deciding it wasn't worth the trouble. He said it would be a lot easier to try and weld on a water jacket.

[wiebe]

Try to get one outbord 4 stroke engine ,there are more around and they are geting old .
One from a sailboat is ok only used to get in and out of the harbor .

Sometime,s its better to get the boat and trailer and motor ,sell the trailer repair the boat ore scrap it .
there is a chance the engine is for nothing then .
The rpm range ok

[BioHazard]

Just some late night math, your prices will vary...

Gas: $1.097/therm
Electricity: $0.11/kilowatt hour

Using fuel consumption from Arrow engines:
1 therm = 12.82hp/hour

Average generator output:
12.82hp = 6.41 Kilowatts per therm (2HP per KW)

2500 watt Cogenerator, 70% heat recovery:
39,000 BTU/hour
2.56 hours/therm
Output = 6.4KW electricity/70,000 BTU per therm
Output = $0.705 electricity/ $0.768 heat per therm
Total = $1.473 per therm (Hey, that's more than I pay!)

Does that look right?

[mobile_bob]

my local rate including all the add on b/s, comes to around $4.75 per mcf, which is just over 1million btu's (natural gas)

when you consider diesel fuel at around 4 bucks a gallon, (somewhat less for offroad) and it having about an 1/8 the btu content
one begins to take a hard look at nat gas

even though a nat gas engine is less efficient than a diesel, (not accounting for cogen heat recovery) the scales still seem to favor
giving nat gas a very very hard look indeed.

when we consider the clean burn (epa likes that, along with neighbors if you have them close) availability if it is already piped in to your house,
reports of having lots of it to burn for a very long time, and its infinite shelf life, well hmmmm

at the price i can get nat gas, i am convinced i can produce electrical power very close to the cost of per kwatt hour from the electric company.

only one way to find out i suppose, that being doing it.

bob g

[Henry W]

I wonder if a manufacture in China would be willing to convert an R175 to run on LP or NG by making a differant head to bolt on.

An ignition pack would not be that hard to put on that engine.
Come up with the desired static compression ratio and go from there.

It would beat designing a complete engine.

Henry

[BioHazard]

I wonder if a manufacture in China would be willing to convert an R175 to run on LP or NG by making a differant head to bolt on.

An ignition pack would not be that hard to put on that engine.
Come up with the desired static compression ratio and go from there.

It would beat designing a complete engine.

Henry

I wonder what the EPA would think of that. That little harbor freight 2 stroke generator is even CARB approved, if we remove the dirty word diesel I wonder what they will let us have?

[mobile_bob]

year ago, cummin rio grande produced nat gas engine's used in irrigation
they used the same heads as their diesel counterparts, the only real difference
was they made a spark plug/adapter to replace the injector, and made a dished piston to lower
the compression a bit, (even though the ntc400 came in at 11.6:1)

i think an adapter could be made easily enough to fit a spark plug into the r175 enabling the use of the diesel head
what would then be needed would be a lower compression piston which shouldn't be a problem for the oem to produce.

it would not be terribly difficult to make an adapter to replace the injector pump to allow linkage externally to the internal governor,  and
provision for a point set cam or plunger to provide for spark ignition, coils are cheap and widely available, just pick a cheap and readily available
point and condenser set such as a small block chevy or ford part?

the oem piston head might be thick enough to cut down enough to get down to around 13:1 comp ratio, which means we don't need the oem to
do anything by provide a stripped down engine, san's injector, injection pump, fuel filter, lines etc.

maybe its time to make a call to the epa? maybe we don't need  to call them?

parts are still legal to import, maybe we import long block 175's?  surely some oem can provide a stripped engine as a part?

bob g

[BioHazard]

parts are still legal to import, maybe we import long block 175's?  surely some oem can provide a stripped engine as a part?

That's the hard part, I've already tried looking for long block chinese diesels to import, but haven't been able to find any unlike the listeroids. Changfa I guess has better things to do. Maybe one of the smaller MFGs if we could put together a large enough order.

[wiebe]

http://www.hobbyking.com/hobbycity/store/__236__55__Gas_Glow_Engines_parts-Gas_Engine_Parts.html
nice and tiny spark makers.

[Thob]

Would something like this engine work:

http://www.smallenginewarehouse.com/product.asp?PN=FD731V-BS07&desc=Kawasaki%20%20%2026HP%20Vertical%201-1/8%22x4-5/16%22%20Shaft,%20Oil%20Filter,%20Electric%20Start,%20Fuel%20Pump,%20Water%20Cooled

Kawasaki 26HP @ 3600 RPM; 2 cylinder, vertical shaft, water cooled, cast iron cylinder sleeves, oil filter.
Low idle is 1550 RPM.
Cost is $999, shipping isn't too terrible.

Can ST generators be run with the shaft vertical?  I seem to think I saw somewhere that they could.

This might me a candidate for running direct drive at 1800 RPM or belt drive at something higher, like 2200 - 2600 RPM.  I wouldn't recommend running at 3600 RPM.  I looked for specs (HP/Torque curve) but didn't find any.

Could this be fitted with an IMPCO carburetor to run on natural gas or propane?

[BioHazard]

Something like that would make a good cogen system, probably slightly less efficient 2 cylinder vs 1 cylinder. I would like to see a power curve for that engine. Surely it could be converted to natural gas/propane.

Here's another horizontal option:
http://www.ebay.com/itm/31hp-Kohler-Engine-ES-Aegis-Liquid-Cooled-EFI-Tomcar-/200766537042?pt=LH_DefaultDomain_0&hash=item2ebe9e3d52

I wonder if the EFI engine would be harder to convert to nat. gas?

[artificer]

Couldn't sleep last night, so I was thinking about the conversion of a diesel engine to NG or LP.  What does it take?  You need spark, fuel, and compression.  Compression is fine, whatever it is.  LP will not autodetonate even at diesel compression ratios, so that makes it easy.  Is NG the same?  Spark is not terribly difficult if you re-use the injector hole.  The listeroids could have the sparkplug in the compression changeover plug.  Use a small engine coil or one of the after-market electronic ignition units.  That only leaves controlling the fuel.  You can get an IMPCO propane carb/throttle body for under $200.  Make a linkage to the governor, or get/make one of the electronic ones.

I have no clue if the engine will run at all well, but I don't see why not.  The thing I'm trying to decide is if it makes more sense to get a small honda civic engine, add a large flywheel, and run it slow at 900rpm.

What causes an engine to wear out?  The number of engine strokes?  Un-oiled starting?  Run the engine slow and adding a pre-run oil pump should make it last longer.  The question is:  just how long?  I've heard of a Honda engine running for 13k hours when it wasn't started all that often.  How long would a cheap used Honda Civic engine last?  I see them on ebay or Craigslist for under $500.

Just musing on the many possibilities.

Michael

[deeiche]

seems like Kawasaki makes a variety of gas powered water cooled v-twins

Kawasaki FD501 16hp brand new

[Derb]

Hi Michael. No need to run a "pre-run" oil pump - there is a product out there called a "bearing saver". It is basically a cylinder which resembles a grease gun. This is fitted up to the oil gallery usually via a tee off the oil pressure switch. Has a spring in it which rests on a piston with neoprene type seals. When you run the engine, the oil pressure of the engine fills the cylinder and compresses the spring. When the engine is turned off a solenoid shuts off flow which leaves the cylinder full of oil under pressure. When you turn on the ignition, the solenoid opens and the oil in the cylinder (under pressure of the spring) pressurises the oil galleries. You can time it down or hook up a start relay off the oil pressure lamp switch. Cheers, Derb.

[Henry W]

seems like Kawasaki makes a variety of gas powered water cooled v-twins

Kawasaki FD501 16hp brand new

That is a good price. One important thing, I would have a couple spare starters. They are not heavy duty. A matter of fact, Kawasaki, Kohler, Briggs starters are not built for continuous start-ups. But all three make good commercial engines.

Henry