diy solar

diy solar

Propane fueled Generators

What oil are you running in your generators? On most engines the valve stems are not supposed to be lubricated by the fuel. If your lp to air ratio is to lean you might be overheating the valves a bit. How much load are you putting on the generators? An engine cannot produce as much power on lp as gas so it would be easier to overload. After reading this I would be careful about overloading an air cooled engine that is converted to lp. https://www.acemechanics.com.au/does-lpg-affect-the-life-of-my-engine-orcar/
 
Is there any way to lube the upper end if you don’t run gasoline? Strictly propane. Would like to get long life out of the 9000 watt champion. Thanks
 
Why do you think the top end is not lubricated? The valve stems and guides get oil from the rocker area. The key to a long life for your genset is:
  1. Oil: clean and full! Change it every 50 to 100 hours depending on the manufacturers specification.
  2. Keep the fins on the head free from debris and the space between the head and the cooling tins clear. Mice and rodents like to build nests which cause over heating.
  3. Adjust the valve clearances according to the manufacturers schedule. It's normal for the valve clearances to tighten a little bit once the hours on the unit start adding up. Tight valve clearances lead to burnt valves and overheating.
  4. Make sure the air filter is changed on time and that it seals perfectly at the edges. Ingesting dirt is the fastest way besides overheating or running low on oil to wear out an internal combustion engine. Clean air is more important than frequent oil changes.
 
LP makes no difference and that ace engines article is just weird.

The engine makes less power on propane because the fuel is in a gaseous state as it enters the cylinder and thus takes up more volume than gasoline which in turns means less room for oxygen which causes a decrease in power.

An engine that's producing less power will run cooler than one that is producing more.

I don't know what they are talking about.

The propane makes almost zero soot so you can greatly increase your oil change intervals. Etc....
 
Checkthisout said:
LP makes no difference and that ace engines article is just weird.

The engine makes less power on propane because the fuel is in a gaseous state as it enters the cylinder and thus takes up more volume than gasoline which in turns means less room for oxygen which causes a decrease in power.

An engine that's producing less power will run cooler than one that is producing more.

I don't know what they are talking about.

The propane makes almost zero soot so you can greatly increase your oil change intervals. Etc....
Click to expand...
Air cooled engines are often designed to run at a specific rpm in order to cool properly under full load. I suppose the potential exists to overheat the valves if the generator is being pushed to it’s max at a reduced rpm because it doesn’t have as much power available from lp as it would have from gas. Until definite studies are made available proving otherwise I would be reluctant to use an lp conversion at max capacity continuously. Most people don’t run their generator anywhere near max capacity continuously but for solar backup where batteries are being charged running an inverter generator at nearly max capacity for extended periods of time is quite likely and potentially damaging if the unit is not cooling sufficiently.
 
Bobert said:
Air cooled engines are often designed to run at a specific rpm in order to cool properly under full load. I suppose the potential exists to overheat the valves if the generator is being pushed to it’s max at a reduced rpm because it doesn’t have as much power available from lp as it would have from gas. Until definite studies are made available proving otherwise I would be reluctant to use an lp conversion at max capacity continuously. Most people don’t run their generator anywhere near max capacity continuously but for solar backup where batteries are being charged running an inverter generator at nearly max capacity for extended periods of time is quite likely and potentially damaging if the unit is not cooling sufficiently.
Click to expand...
It's running at a lower speed because it's making less power and thus less heat is generated, which is different than running at a lower RPM because it's being overloaded in which case it's still generating the same amount of heat but at a lower cooling fan speed.

It's so subjective that it's meaningless. Cheap inverter generators like champions and such will suffer failures no matter how they are treated and something else is much more likely to fail before the motor does because it was run on a cleaner burning fuel than gas.

Some cheap generators run dual fuel setups from the factory. Are they beefing up those units to run on propane any difference in valve seat and valve part #s and cooling fan setups vs the single fuel?

I bet not.
 
Last edited:
If your valve clearances keep tightening up then you are suffering from valve recession.Propane is hard on both the valves and valve seats. If the mixture is slightly rich this will make the situation worse as combustion temperatures will increase. On propane powered engines I used to run one of these style kits. https://www.ebay.com/itm/302793198795
We never bothered with their fluid and ran two stroke oil in the reservoir. The other option is to fit hardened valve seats, good quality valves and bronze valve guides. Hope this helps.
 
Checkthisout said:
It's running at a lower speed because it's making less power and thus less heat is generated, which is different than running at a lower RPM because it's being overloaded in which case it's still generating the same amount of heat but at a lower cooling fan speed.
Click to expand...
The problem is that propane burns hotter than gasoline and although the engine as a whole will run cooler the valves will not. The only way to effectively reduce the valve temperatures without modifications is to run the generator well below it’s rated load when using lp instead of gasoline.
 
Bobert said:
The problem is that propane burns hotter than gasoline and although the engine as a whole will run cooler the valves will not. The only way to effectively reduce the valve temperatures without modifications is to run the generator well below it’s rated load when using lp instead of gasoline.
Click to expand...
Propane does not burn hotter than gasoline.

Burnt valves implies high exhaust gas temperature which would be the result of a fuel that is burning slower, not faster or hotter.

During normal operation on gasoline, Honda and Yamaha recommend you remove the cylinder head on a regular interval to decarbonize it. They would only recommended this because they think the soot is building up and will eventually start to creep over to valve seats and begin to hold the valves open causing them to burn and they are concerned the carbon will cause hot spots (if the generator sees a high load) which would lead to detonation. (Pinging)

If we ran propane we wouldn't ever have to perform this maintenance item.
 
Every 300 hours you're supposed to pull the head and clean the carbon off. I wonder if propane is more likely to burn the valves or not performing this service at a regular intervals?

Screenshot_20220718-082336_Drive.jpgScreenshot_20220718-082520_Chrome.jpg
 
My experience with Onan running on propane produces virtually no carbon scoring, deposit, etc.
The oil always looked the same coming out of the drain as it did when we put it in.
 
Checkthisout said:
So a difference of about 100 degrees Fahrenheit?

Propane peaking out 4220 degrees Fahrenheit vs 4120 Degrees for gasoline?

Why would that add more heat to the cylinder, pistons and valves than gasoline but not make more power?
Click to expand...
Part of the picture is that gasoline has to be vaporized when it comes into the cylinder so it’s incoming temperature is substantially lower than that of the propane and when propane is compressed it gets hot like a refrigerant so that the combination of those two factors creates higher burn temperatures.
 
Bobert said:
Part of the picture is that gasoline has to be vaporized when it comes into the cylinder so it’s incoming temperature is substantially lower than that of the propane and when propane is compressed it gets hot like a refrigerant so that the combination of those two factors creates higher burn temperatures.
Click to expand...
I think it's inconsequential.

I think the assertions about valves burning are from the days when fuel had lead in it.

Propane had no lead so valve seats would wear prematurely.
 
In the last year I have bought a Honda 2200i inverter gen set ( I converted it to dual fuel) ,a champion dual fuel 3500 inverter gen set and a 9000 champion dual fuel… installed a 1000 gal propane tank plumbed to feed all three gen sets for long term use , and to help power my RV heat and appliances…I ran and practiced living off all three gen sets about 50 to 100 hrs each on gas , no prob and then switched to propane … and still no problem …now I discover that propane is Gona mess them all up .. first I ever heard of this, but it must be somthing to it or y’all wouldn’t be discussing it…I don’t want to be a small engine mechanic..im done with dirty hands …
the gens were purchased to act as supplemental power and to assist this damn “Demonic“ diy solar system that gets all my attention, money and time trying to finish it….by this fall.

this propane stuff is not good news to hear… I thought it would make things a lot simpler and cleaner. I have had many gas and diesel gen sets in my life on boats and houses . Gas is a messy and dangerous thing to store in any large quantity, or treat ,preserve and count on long term ..I hate gas .. and storing diesel is worse…if you spill some it stinks forever and the local EPA will come take you away..……Is anything easy anymore ?.. Last week I filled up my propane for about 2 bucks a gallon and thought I was set…,now I’m depressed..
 
Jim H said:
In the last year I have bought a Honda 2200i inverter gen set ( I converted it to dual fuel) ,a champion dual fuel 3500 inverter gen set and a 9000 champion dual fuel… installed a 1000 gal propane tank plumbed to feed all three gen sets for long term use , and to help power my RV heat and appliances…I ran and practiced living off all three gen sets about 50 to 100 hrs each on gas , no prob and then switched to propane … and still no problem …now I discover that propane is Gona mess them all up .. first I ever heard of this, but it must be somthing to it or y’all wouldn’t be discussing it…I don’t want to be a small engine mechanic..im done with dirty hands …
the gens were purchased to act as supplemental power and to assist this damn “Demonic“ diy solar system that gets all my attention, money and time trying to finish it….by this fall.

this propane stuff is not good news to hear… I thought it would make things a lot simpler and cleaner. I have had many gas and diesel gen sets in my life on boats and houses . Gas is a messy and dangerous thing to store in any large quantity, or treat ,preserve and count on long term ..I hate gas .. and storing diesel is worse…if you spill some it stinks forever and the local EPA will come take you away..……Is anything easy anymore ?.. Last week I filled up my propane for about 2 bucks a gallon and thought I was set…,now I’m depressed..
Click to expand...
Running your trio of gens on propane is the best thing you can do for them.

They'll make less power but I can't imagine you bought inverter generators just to load them to 100% output.

Their oil will stay cleaner. Their emissions wont give you headaches and stink up your little piece of paradise.

You're a good generator dad.
 
  • Like
Reactions: JRH
I have an Onan 6300 propane which recently started running bad (sounds like it drops to one cylinder), only once it gets fully hot (runs perfect on cold start and for 20-30 minutes). I have a sneaking suspicion that it has a tight valve (lash is closing up and valve not seating when it gets hot only).

I have a friend who sells Amsoil and he is saying I need to put Amsoil in it (as if I should try that first). I do have Amsoil in my big box truck and it seems like it's a good synthetic, but I still think I have a tight valve (which even awesome oil won't fix).

I've replaced all the other tuneup parts but once it gets hot it bogs down and sounds like it's only hitting on one cylinder, so I think I will adjust the valves next. I don't know how many hours is on it...
 
Last edited:
Samsonite801 said:
I have an Onan 6300 propane which recently started running bad (sounds like it drops to one cylinder), only once it gets fully hot (runs perfect on cold start and for 20-30 minutes). I have a sneaking suspicion that it has a tight valve.

I have a friend who sells Amsoil and he is saying I need to put Amsoil in it. I do have Amsoil in my big box truck and it seems like it's a good synthetic, but I still think I have a tight valve.

I've replaced all the other tuneup parts but once it gets hot it bogs down and sounds like it's only hitting on one cylinder, so I think I will do that next. I don't know how many hours is on it...
Click to expand...

Amsoil to fix a misfire.

Amsoil to improve your sex life.

Amsoil to win your crush back.

When you're a hammer everything's a nail.

Compression test it when it's hot and see what you come up with. It's probably a waste spark Ignition but still worth checking spark when it gets hot.
 
Take head off to remove carbon?

After one tank of bad gas on a trip into Mexico, my '64 Superhawk would detonate badly under low-RPM high-torque operation. Severely boosting octane would stop that.
I finally sprayed water from a squirt bottle into the intakes while revving it. Soot came out the tailpipe. Detonation problem solved.
 
You must log in or register to reply here.

Similar threads

jimf909
AGS - Auto Generator Start Information Thread
2
Replies
24
Views
2K
jimf909
jimf909
A
Generator Selection for Off-Grid Setup
2
Replies
20
Views
3K
Crowz
Crowz
Back
Top