Honda Gen and propane

[Ken in Anaheim]

I'd rather not keep raw gas in the van. Anyone have any experience with the Honda generators (or others) converted to propane ?
KinA

 

[SoulRaven]

I did not convert mine (Honda), I was told it would void the warranty.Doing my research on converting found most folks on the RV.net tech site weren't too keen on it. The following is an excerpt from one of many threads on the subject.

RE: Generators - Gas, Diesel or Propane, Best makes models?

About propane... I hope to never ever need a generator at all, didn't need it so far, South of the border my solar generates more energy than I can consume. But you know what they say - never say "never". So I did some digging on propane gennies in terms of noise, fumes, and portability. Here is what I found: Propane generators (meaning propane-only) have several times shorter life than diesel or gasoline gennnies. Same goes for natural gas generators - short life. Propane generators are hardly portable - in any event this isn't something that you can lift or carry. Loading and unloading it would be a pain. For running it more than few days non-stop (or more than 12 hours a day) you would need a stationary tank. Fumes - no contest here, propane is cleaner than gasoline or diesel genny. Cleaner exhaust and less smell around the tank. Noise - marginally quieter than gasoline. Which means - too loud for me to use it regularly. As an emergency-only, maybe yes. To be fair to propane gennies, all so-called "quiet" gasoline gennies like Honda EU2000 are understating their noise, quoting 55-59 db while in reality it's 70-75 dB at 10ft distance.

 

[AltTransBikes]

Yamaha has a 2000 watt tri-fuel genset.

Modern generators in a sound box can be very quiet. Youtube Honda 2000i quiet.

 

[ccbreder]

Propane internal combustion engines last as long if not longer than gasoline fueled engines. Fact.

 

[Optimistic Paranoid]

Question:

The ic engines on forklifts run on LIQUID propane, not propane vapor.

Does anyone know which the converted generators use?

If they also run on the liquid propane, you won't be able to run them off the same tank you use for your stove and heater, if that was your plan.

Regards
John

 

[BamaDuke]

The liquid propane is allowed to expand as a gas before it is delivered to the engine. Propane "boils" at a few degrees below freezing, depending on the exact mix. The propane cylinder you have for the rig or your grill has boiled off enough gas to pressurize so that you will get gas flow when you open the valve.

Propane never goes bad, unlike gasoline or diesel. For a generator to be used once in a blue moon, I would seriously consider a propane fueled unit. I would want one, though, that would ONLY run on propane. This way the differences in compression ratio, engine ignition timing, and oil requirements for propane versus gasoline would be taken into account by the manufacturer.

There are also natural gas generators sold for backup in homes where there is natural gas service. This would be the only instance I can think of where the fuel was not stored in a liquid state.

I have used propane in forklifts and in pickup trucks. I am not sure where the idea that propane fueled units have shorter lives than gasoline fueled units. I have never even read that anywhere. Propane is delivered to the combustion cylinder as a gas, not as a liquid. Unburned Liquid gasoline dilutes engine oil, and leaves a great deal of carbon in the cylinder. These cause much wear in an engine. Propane does not have these effects. If someone keeps a propane generator for emergencies, and forgets to change the oil, then perhaps the engine will fail quickly. But the same would hold for any fuel.

If I wanted to replaced the generator I removed from my Class C, I would keep an eye on Craigslist. The first usable generator that came up would likely be my pick, regardless of fuel type. If money were no object, a big, bad, propane fired Generac would be my first choice. But the Scotsman in me would scream....

Bama

 

[Optimistic Paranoid]

The liquid propane is allowed to expand as a gas before it is delivered to the engine. Propane "boils" at a few degrees below freezing, depending on the exact mix. The propane cylinder you have for the rig or your grill has boiled off enough gas to pressurize so that you will get gas flow when you open the valve.

Lets see if we're not talking at cross purposes here. AFAIK, all propane tanks are considered filled at 80% That is, the bottom 4/5 of the tanks are full of liquid propane, and the top 1/5 is full of propane vapor.

Bbq tanks take their feed from the top and feed propane vapor to stoves, heaters, etc.

Forklift tanks take their feed from the bottom and feed liquid propane to the engine, where some doohickey ( technical term ) converts it to a vapor and feeds it to the cylinders, just as carburetors convert liquid gasoline to gasoline vapor.

The main point is, you can't run a forklift from a bbq tank, and you can't run your bbq from a forklift tank.

Which brings us back to my original question: do these propane generator conversions need a liquid or a vapor feed?

Regards
John

 

[Oberneldon]

Vapor

 

[flailer]

Please correct me if I am wrong here ~

The "idea" that NG or LP engines do not last as long as Gasoline is based upon the FACT that Gasoline has more units of energy (per volume) than LP, and that LP has more units of energy than NG.
CLICK-LINK

The "idea" is based upon the thought that LP engines, and NG engines in particular, must "work harder" to produce the same horsepower as a Gasoline engine.

From what I have heard, people using these engines for highway use agree: there is less horsepower available.

So, engine designers compensate, as much as they can, and larger displacement goes a long way towards solving this "power gap"

BUT: Just who in the heck can say that a 5.4L V8 engine doesnt live as long (wears worse) than a 4.7L V8 engine ???? I can't. But who am i?

Now, add to this mix the new CNG (compressed natural gas) engines, and you have a REAL spreadsheet of data to work with.. (Horsepower, Price of fuel, Cost of conversions, Mileage, Cost/mile, range, Engine temp, time between rebuilds, std maintenance practices, where can you buy fuel , flex fuel design work with? , , )

CNG LINK#1
CNG LINK #2


I know of no independent studies. I only offer this as food for thought, and hope to learn something from you guys.

 

[johnny b]

Please correct me if I am wrong here ~

The "idea" that NG or LP engines do not last as long as Gasoline is based upon the FACT that Gasoline has more units of energy (per volume) than LP, and that LP has more units of energy than NG.
CLICK-LINK

The "idea" is based upon the thought that LP engines, and NG engines in particular, must "work harder" to produce the same horsepower as a Gasoline engine.

I know of no independent studies. I only offer this as food for thought, and hope to learn something from you guys.

OK, here it is in a nutshell.
If propane has 75% of the BTU content of gasoline, then increasing the volume of fuel by 25% brings it up to equal power output.

In todays modern flex fuel vehicles, the ECU compensates by adjusting the fuel injection and ignition timing to run E85.

In race cars that use carburetors, you have to install larger jets to run methanol (50% of BTU's of gas).

You were half way to your answer in your first sentence "...per volume".

Vehicles and/or equipment using fuels other than gas do not use the same volume, therefore do not 'work harder' nor wear out quicker.

---

Almost forgot...a quick google came up with these sites for conversion kits:

https://www.propanecarbs.com/
http://www.motorsnorkel.com/
http://www.centuryfuelproducts.com/

 

[ccbreder]

On these small generators, the conversion uses the propane gas not the liquid.

 

[flailer]

In todays modern flex fuel vehicles, the ECU compensates by adjusting the fuel injection and ignition timing to run E85.

Thanks - I got that. I have a buddy that has his own business-shop for race cars. They run (& tune) for E85 , and gets better performance (than on E10, for example)

BUT, as they have money to burn, it is not uncommon for them to rebuild the engines mid-season (yeah, they are not professions, they "only" cater to Fat-Cat business owners in the Silicon Valley, so they don't rebuild every race)

.... so, the question still remains on maintenance and service cycles on LP NG & CNG engines.

p.s. I'm really sorry if I am dragging this thread in a direction it shouldnt be going .... :-/

 

[ccbreder]

As propane doesn't burn as dirty as gasoline, and doesn't wash down the cylinder walls, you could get longer service cycles on the oil. But an oil change on these small engines is not such a big deal why not change it on the manufacturer's scheduled? And it is always good to keep a good air filter.

---

I did some quick reading about propane powered forklifts and tractors. Much less maintenance costs and two to three times the engine life. Some tractors have more power on propane because of higher octane of propane.

 

[johnny b]

Thanks - I got that. I have a buddy that has his own business-shop for race cars. They run (& tune) for E85 , and gets better performance (than on E10, for example)

BUT, as they have money to burn, it is not uncommon for them to rebuild the engines mid-season (yeah, they are not professions, they "only" cater to Fat-Cat business owners in the Silicon Valley, so they don't rebuild every race)

.... so, the question still remains on maintenance and service cycles on LP NG & CNG engines.

p.s. I'm really sorry if I am dragging this thread in a direction it shouldnt be going .... :-/

you're comparing apples to oranges....

when building a high performance engine there are many more variables than just fuel volume...too many to discuss here.

So....2 generators of the same make and model rated at 5 horsepower on gasoline. install a kit for propane and adjust fuel flow to run at the same 5 horsepower on one of them. the one running propane will run cleaner and last longer ALL OTHER THINGS BEING EQUAL.

with propane there's no 'cylinder wash down' during a rich cold start...i.e. choke on.
there's also less carbon 'blow by' of unburned gasoline past the piston rings...which is the main cause of 'dirty oil'.

gasoline does not turn 'gaseous' as it enters the combustion chamber...it is atomized either by the carburetor or fuel injector and mixed with air forming an 'aerosol' of fine liquid particles.

gasoline as a liquid therefore still has some of its 'solvent' properties which is part of the 'wear and tear' factors involved in the life of an internal combustion engine.

propane and natural gas are utilized in a gaseous state and therefore have less 'solvent' properties resulting in cleaner running and less maintenance.

Clear as mud, right?

ps--i do not know how forklifts that deliver liquid propane to the engine actually process the fuel. since it 'boils' into its gaseous state at -45 F unless under pressure. i will look into it, though because i'm the curious type. :huh:

 

[johnny b]

I did some quick reading about propane powered forklifts and tractors. Much less maintenance costs and two to three times the engine life. Some tractors have more power on propane because of higher octane of propane.

Hate to be a pain, but octane does not produce power.
Octane is a rating of a fuel's ability to stop 'pre-detonation' or 'knocking' which can ruin an engine.
An engine can be built to produce more power and require a higher octane to run without damage...but it is not the high octane of the fuel 'making' more power.
If you fill your generator with 'high octane' gasoline (say 93) when the manual says to run it on regular 87, all you're getting out of it is less money in your wallet. Which is also why the 100-110 'octane' of propane doesn't improve the power of a generator conversion and the fuel flow is adjusted. All about the energy content of the fuel (btu) as discussed earlier.
Same with your vehicle...run it on the least octane you can that doesn't 'knock'...i.e. the cheapest.

OK now I'm rambling, time for another beer.

 

[ccbreder]

Yes. You rambled right off the page. I hope it is Good beer.
I just reported something farmers have discovered with some of the tractors and am sorry if I caused any confusion over fuel ratings. Not. Don't give up the beer.
I am not sure with modern gasoline. My experiences were in the 50's. Most automobiles of that era, got better gas mileage using "super" grades of a given brand of gasoline. Mostly enough to cover the extra cost.
Most.

 

[flailer]

you're comparing apples to oranges....

.....

ps--i do not know how forklifts that deliver liquid propane to the engine actually process the fuel. since it 'boils' into its gaseous state at -45 F unless under pressure. i will look into it, though because i'm the curious type. :huh:

Thanks. which is why i clarified, and asked again. Thanks: We have proofs? (proof that cleaner burning means longer engine life) ??

In my opinion (opinion) the by-product of combustion (carbon, i.e. "carbon black") are of such a small size, sub-micron in fact, that they do not contribute to engine wear. Do they make the oil black? YES. But do they cause wear??? I don't think so. If they did filtration (or separation of some kind) would be added, and would become standard equipment on internal combustion engines.

Sub-micron filtration is standard in many industries because it give benefits.

I would guess (guess) that they simply use a pressure regulator on these liquid propane rigs. And thereby get the "phase change" in the fuel at the regulator, at the engine, rather than at the tank. shrugs.

but who am i? don't take my word on these points

 

[ccbreder]

The proof of longer service life is by 100's of thousands of forklift experiences. On a forklift the fuel is vaporized in what would be called the carburetor. Different than liquid gasoline which is atomized.

 

[BamaDuke]

I am not sure we are all looking in the same direction...

Octane is indeed a measure of a fuel's resistance to detonation. A fuel with more resistance can be used in an engine with a higher compression ratio. Higher compression ratios allow an engine to produce more power than lower compression ratios in that engine. As I stated earlier, I would look for a generator with an engine designed by the manufacturer to burn the fuel I wish to use. That way, the engine has been optimized for that fuel, by changing compression ratio, ignition timing, etc.

The unburned carbon in a gasoline engine is the major source of wear. The SAE has plenty of papers explaining the concept. These very tiny particles foul the oil and greases, much like very fine sand. In my younger days, I acquired knowledge regarding sand in lubricants at the beach with my girlfriend

Bernoulli explained the Law of Partial Pressures, among other things. When a gaseous fuel is mixed with air, as in all propane fueled engines (it doesn't matter if the regulator is at the tank or at the engine, the fuel is still mixed as a gas), the fuel is evenly distributed in the charge delivered to the cylinder. Liquid fuels use atomizers, just like a perfume dispenser. There are small and not-so-small droplets. This results in a not quite perfect charge delivered to the cylinder. Fuel injection is much superior to the old carbs, but it is not perfect either.

But all this is just minutia. I like the idea of a propane, especially for an engine that will not be used on a regular basis. But I'm not sure how much extra I would be willing to pay for it.

Bama

 

[bcbullet]

I am going to just say one thing....I have a factory propane Dodge van and it is great on the wallet and strong on the highway. Actually make that two things: I also have a 1000 watt honda generator that has had the float bowl bowl pulled off so many times to clean out the main jet from stale ethanol blended gas that I can do it in my sleep. So back to the propane generator question, I would trade 200 watts of output to run the gennie on less energy dense propane in a heartbeat. 
(And I agree that the propane runs cleaner in the van...3 things! :blush