Propane question re dual fuel gens

[dobarker]

Txaz is on it. In NG or propane operation, the carburetor only acts as a vacuum producer to pull the already gaseous fuel through the regulator and into the cylinder.

Yes it goes through the carb.
The carburetor is used to mix the LP or NG with air, and the Venturi in the carb helps mix that gaseous fuel and air into a more consistent mixture.

I bought a 10kw generator dual fuel (Gasoline / LP), and converted it to handle trI-fuel options (Gas, LP abd Natural Gas). I bought a kit Took the carb inlet apart to add NG and you can see different ports for LP and NG.
The trick is to make sure you’re only using one gas spot a time. Not a problem with generato with a selector switch.

More power demand = more vacuum = more fuel delivered. Simple way to think of it if you’re mechanically inclined is like the old vacuum advance distributor. Higher demand leads to more vacuum leads to more of fuel/air mix leads to advanced timing.
Just a word of warning, it’s a rabbit hole of “what if” and experimentation if you convert to natural gas or tri-fuel.
I’ve now messed with 8 different generators converted from gasoline or dual fuel to natural gas. Then figured “why not” and drilled out the orifaces in my propane grill to convert it to NG as well.

 

[jmohme]

The forklift guy i used to know told me that propane fueled engines never get slugged up. They run a lot longer than gas engines due to not carboning up. The propane does not foul plugs, and oil is honey colored when changed, not black like gas.

Correct.
I maintained a fleet of propane delivery trucks and yes they ran very clean. Spark plugs always looked new, but the electrodes would wear away badly, so they still would need replaced eventually. And yes, oil was always looked clean, but the additives would still deplete so it had to be changed. I alway felt bad dumping it in the waste oil tank, but oil analysis does not lie.

The biggest problems we had were the converter that converted the liquid propane to gas. They would get gummed up with what looked like tar that was a real PITA to clean out. The converters would also freeze up in cold weather. Once thawed out they were good for the day since the converters were kept warm with engine coolant.

The other thing that was kind of suprising was that they went through spark plug wires a lot quicker than their gasoline powered versions.

I don't know about now. This was back in the 80s, so I would imagine things have changed a lot.

 

[Lead Belly]

Liquefied Petroleum Gas (LPG)​

LPG is a mixture of propane and butane. These hydrocarbons are byproducts of the natural gas and petroleum refining processes. LPG is stored and transported as a liquid under pressure. The most common applications for LPG include cooking, heating, and as an alternative fuel for vehicles. Generally, propane and liquefied petroleum gas (LPG) mean the same thing, However, the latter can contain butane and isobutane.


The propane cylinder has liquid propane in it, that liquid sits on the bottom, but it doesn't want to be liquid- it wants to go back to gas (unless chilled) but is constrained by the strong metal tank. Think of a warm soda bottle- the carbon dioxide is under pressure so it is liquid (in suspension). If you open it, it escapes. Open a warm 2 liter bottle of soda... and the unregulated escaping gas carries the liquid out with it. No bueno. Propane gas (at the top of the cylinder) is under great pressure, so the pressure regulator reduces the escaping gas pressure to a consistent metered level.

Boyle's law, a gas law that states that the pressure and volume of a gas are inversely proportional at constant temperature and quantity.


Dual-fuel Carburetor

The dual-fuel carburetor handles liquid gasoline like any carb- liquid gas sits in the float bowl where the venturi (moving air) carries the vapor into the engine. The amount of gas is limited by the float that rises when the bowl is full and pushes a needle valve into a seat, preventing more liquid gasoline from entering the bowl. The gold butterfly controls the air entering the carb.

The propane component of the carb already has propane vapor coming into the carb in gaseous state, so it bypasses the floatbowl. It does have an electronic valve to control the gas supply as the float needle would do in the liquid gasoline example.

Photo below shows gold gasoline nozzle on bottom using the black spring-wrapped hose. The secondary regulator on right side with priming button in center (to release trapped air in line). Black lever at very bottom is control to switch between fuel types. The black wires on far right go to the electric control valve for the propane side.






Converting to natural gas:

If you want to use natural gas instead of propane, you will need a different secondary regulator with a larger diaphragm- the larger the diaphragm disc, the more precise it can be. You would bypass both of the natural gas regulators- high pressure one by tank and the secondary metering regulator as in photo. Tri-fuel generators have a 3-way selector valve built-in.

Pictured is correct larger Garretson KN secondary natl gas regulator- the primary regulator is over by your gas meter- it takes the higher pressure transfer gas down to the proper pressure for your appliances- measured not in PSI, but inches per water column. These secondary regulators as in photo are sized by engine flow demand and specifications are marked.

Garretson KN natural gas regulator


Always hire a pro for install if you are unsure.

 

[Eli]

It's not a regular carb. Gas goes the usual bowl/float/needle valve route, propane is metered directly into the firing chamber thru a different path in the carb body. There's a switch/lever to choose between the two. The propane setting will still work if ethanol plugs up the gasoline side.

Yeah, any spark-ignition needs a throttle body to regulate air intake - Diesels don't.
These tri-fuel generators really intrigue me!

Eli

 

[Eli]

Yeah, any spark-ignition needs a throttle body to regulate air intake - Diesels don't.
These tri-fuel generators really intrigue me!

Eli

Specifically, this one:

Sportsman Generator Combo

This summer special Sportsman Generator Combo will save you money! It includes one tri-fuel generator powerhouse, plus a gas fuel portable generator.

www.buffalocorpstore.com

Eli

 

[1911'S 4 Me]

Specifically, this one:

Sportsman Generator Combo

This summer special Sportsman Generator Combo will save you money! It includes one tri-fuel generator powerhouse, plus a gas fuel portable generator.

www.buffalocorpstore.com

Eli

I have a Sportsman dual fuel. It ran perfect during Beryl on propane.

 

[User1776]

Are they quieter on propane or fuel?


Sent from my iPhone using Tapatalk

 

[jmohme]

Are they quieter on propane or fuel?


Sent from my iPhone using Tapatalk

no

 

[MountainGirl]

no

LOL He was just on a post run.

 

[User1776]

LOL He was just on a post run.

Actually I was genuinely wondering. I own a dual fuel. May try minding your own business.


Sent from my iPhone using Tapatalk

 

[Tnhawk]

Actually I was genuinely wondering. I own a dual fuel. May try minding your own business.


Sent from my iPhone using Tapatalk

Congrats. First ignore of the week!

 

[MountainGirl]

Actually I was genuinely wondering. I own a dual fuel. May try minding your own business.


Sent from my iPhone using Tapatalk

Oh dont be a shit.
Your intro said you were interested in buying/selling guns
Maybe you have something I'd like.
Or maybe not.

 

[no2gates]

Congrats. First ignore of the week!

Slow week? That's my third.

 

[Lonesome Dove]

I'm on an ignore roll as well, added.

 

[User1776]

Oh dont be a shit.
Your intro said you were interested in buying/selling guns
Maybe you have something I'd like.
Or maybe not.

What did your intro say? “Here to troll other peoples posts and act like an ass“.


Sent from my iPhone using Tapatalk

 

[Vaquero]

Chill

 

[MountainGirl]

What did your intro say? “Here to troll other peoples posts and act like an ass“.


Sent from my iPhone using Tapatalk

Only on a slow day.

Good luck with your sales!

 

[no2gates]

What did your intro say? “Here to troll other peoples posts and act like an ass“.


Sent from my iPhone using Tapatalk

 

[Tnhawk]

It ain't over till the hammer drops!

 

[Hoji]

Nah. The right folks are aware.