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

[BioHazard]

What makes the Marathon engine so special?  I've heard of Honda engines running for 10,000+ hours.  If you doubled the size you need, and run it half speed, could you get similar life out of the Honda?  Running it on propane or natural gas will help last a long time, and increase the maintenance interval.  I'm just wondering if there's any breakthroughs in technology, or is it just how the set them up?

I think their main advantage is water cooling. Not only does that make it easier to use the waste heat but I think the engine will last longer in the long run with better thermal stability. Also has a pressure lube and filter system. Other than that I think it's mostly a Briggs and Stratton on steroids.

I like the idea of using "commodity engines" as you say, just pop the engine out and replace it with another $200 unit every few years. Too bad there aren't any water cooled engines like this. Briggs makes a 6.5hp OHV lawnmower engine with pressure lube and filter that can be had on ebay quite cheaply. I suspect it's very similar inside to the Marathon engine. I've long been thinking of trying to water cool an engine like that.....

[deeiche]

SNIP

I like the idea of using "commodity engines" as you say, just pop the engine out and replace it with another $200 unit every few years. Too bad there aren't any water cooled engines like this.
SNIP

Take a look at this scooter engine 110cc water cooled motorcycle engine kick start.  Perhaps a group buy?

[BioHazard]

I've seen chinese water cooled bike/ATV engines on ebay before, can't seem to find one right now. They're usually designed for high speed use though. Kind of hard to take one seriously as a "work" engine.

We've talked about this before, but this would be an ideal setup:
http://www.arrowengine.com/Products/Single_Cylinder/K_Series.php
Obviously arrow is importing indian engines and adding spark ignition. You can still order an "air compressor" listeroid, probably easier to convert to spark than diesel. I wonder what Arrow is using for a governor?

It always just boils down to cash, how much do you wanna spend?

[Derb]

Hi Fellas. Cant see the motorcycle engine being much cop for stationary work. Cylinder head is still air cooled design - where much of the heat is generated. Cheers, Derb.

[deeiche]

I've seen chinese water cooled bike/ATV engines on ebay before, can't seem to find one right now. They're usually designed for high speed use though. Kind of hard to take one seriously as a "work" engine.

SNIP

I brought it up because you've referenced cheap 2-stroke generators before, so I figured this couldn't be any worse.   

[Lloyd]

You guys are missing an opportunity.

4 cycle marine outboards  are water cooled electric start, with a linear throttle, the come in hp ranges from 5 hp all the way to 300 hp, they have good low end torque. The power head would be an easy adaption to mount.



Check this company's new product out... www.goleher.com its a propane powered 2.5 hp and a 5 hp outboard engine. Guess what it uses the Mercury Outboard, with propane conversion. Yamaha Outboard is a re-baged  Mecrury.

Lloyd

[Henry W]

Hi Lloyd,

I was looking at those about 2 months ago. If they use a Mercury power head than it is manufactured by Tohatsu. They make very good engines.

Henry

[LowGear]

How come such smart ideas are so obvious once you see them.  Fire up the Barbee and the boat with the same fuel bottle.

This same idea might get gasoline powered golf cars back on some courses where they're banned.

Unfortunately propane is $5 a gallon here in Paradise.

Casey

[Lloyd]

Henry, you're probably right, with the Global Economy, some much consolidation, it's by acquisition, or it's by contract manufacturing, re-badging.

I posted awhile back about this little 3KW Westerbeke gas gen set, with the remark that it would be an easy conversion to LP/nat gas. Funny thing is they took an outboard motor powerhead adapted it to a frame and belt driven AC genny, and are running it at 2200 rpm. http://www.westerbeke.com/Products/ProductDetailLanding.aspx?ID=1284


LowGear, There is not much new under the sun, just a different way of using an existing technology, and off the shelf parts.

Lloyd

[Henry W]

I remember that unit. Sure is a pretty thing.

Henry

[Henry W]

Ouch!!! Check the price out.

http://www.norwall.com/categories/Marine-Generators/Gasoline/

[BioHazard]

Here's some more info on the Marathon engine, wish they had more details.
http://www.marathonengine.com/about_the_marathon_engine.html
If you click on the picture of the engine the animation looks very very similar to the inside of the Briggs Intek engines. It just so happens the Intek was designed/introduced right after they sold the "Marathon" division.

It is of course, cast iron water cooled as opposed to aluminum air cooled. Damn I wish I could buy one of them things! It really makes me wonder what kind of engine life you could get out of a standard cheap intek, if run continuously at low speeds on nat. gas.

[mobile_bob]

i wonder how hard it might be to mock up a pattern for a crankcase, to accept Briggs and Stratton, honda or other internal parts, and make it
a wet sleeve water cooled engine?

using existing internal parts, such as crank, rod piston, valve train, and overhead valve head, along with all the other stuff, might make it doable.

maybe the crankcase could be aluminum alloy with a replaceable iron wet sleeve.

maybe start with an aircooled crankcase, cut the cylinder off the top, fab up a wet cylinder and glue it one with epoxy, feather it in with bondo
and send it to china or india for casting and basic machining?  that way all the bottom end spacing would be established, things like main brg bore, cam centerlines etc would be taken care of.

a good pattern would allow for an interesting option in my opinion.

bob g

[mobile_bob]

alternatively, maybe there is a single cylinder aircooled engine that could have its fins machined off, and a water cooled jacket made
and fitted to it?

we need an engine that is water cooled, widely available, and affordable

maybe we can only have any 2 but not all 3?

bob g

[artificer]

I had been thinking of two of the ideas that have been brought up:  outboard and cutting the fins off of one of the cheap honda clones.  I don't know anything about outboards, so I don't know how long they would last.  I was thinking that light, high speed, high power/weight ratios  wouldn't make a decent long running engine.  Do they have cast iron bores/inserts?  If they do, then its a matter of getting a larger one and  running it slower with a flywheel.

For the Honda clone, I was looking up the GX200 parts diagrams.  The cylinder/crankase isn't that simple of a part to cast.  I was thinking that machining off the fins and having a bolt-on/clamp-on water jacket would make the most sense.  I like the idea that anyone with a bit of mechanical ability could use a sawzal and grinder to convert a commonly available engine.

For the water cooled motorcycle engine...  the same procedure could be used for the head.  You could then have a totally liquid cooled engine.  Then again, maybe its the selection of engine.  I'm pretty sure that goldwing engines are totally water cooled.  Others probably are as well.  Downside is cost, of course.

Michael


GX200 cylinder casting