Propane Powered Engines Featuring a 7.3 Ford and 6.7 Cummins

a spark ignition engine designed for propane operation is capable of high power output and efficiency, since propane like alcohol has a higher octane rating one can run much higher compression and much more spark advance.

Course it will use more gallons of fuel than gasoline due to the lower energy content, but it gains in thermal efficiency to partially offset.

Dual fuel engines another story, spark advance can be adjusted but not easy to adjust compression ratio.

agesilaus wrote:

I bet the valves will love it

I doubt it, diesel engine valves get lubrication from the fuel. That is an issue with low sulfur fuel, it provides reduced lube.

in a diesel fuel is injected into the cylinder after the valves are closed, not sure how it provides any lubrication.

Back in mid 70s friend had most of his inherited farm leased out, but kept old WD 45 around for chores. Had converted it and a old VW bug to run on propane. I talked to him when noticed he was driving the car on days he would normally ride his 750 Honda. He just fueled car and tractor from tank installed to heat the house, was less fun, but cost less to drive the car

I bet the valves will love it

I doubt it, diesel engine valves get lubrication from the fuel. That is an issue with low sulfur fuel, it provides reduced lube.

Turtle n Peeps wrote:
Propane:

The good:
#1. Clean burning fuel.
#2. Engine oil pretty much last forever.
#3. Fuel lasts forever over time if not used. (think genset that is only used very seldom.)
#4. Octane value.

The Bad:
#1. Energy density; gas=100% propane=66%. (mileage)
#2. Power output. (Waaaay down on power)
#3. Poor starting in cold weather. (If not impossible)
#4. High cost/energy density.
#5. Heavy tank needed.
#6. Large tank needed.
#7. Hard to find compared to gasoline.
#8. Hard on valves.
#9. Takes a long time to fuel up.
#10. Vehicle cost a lot more if duel fuel.

Pretty easy to see who wins.

A few rebuttals:

I question the power too, but this guy claims they can meet the same power output now.

Also in a DI engine I bet the valves will love it. Seen forklifts run on propane with no valve issues

Doesn't take as long as charging that F150 Lightning.

Propane:

The good:
#1. Clean burning fuel.
#2. Engine oil pretty much last forever.
#3. Fuel lasts forever over time if not used. (think genset that is only used very seldom.)
#4. Octane value.

The Bad:
#1. Energy density; gas=100% propane=66%. (mileage)
#2. Power output. (Waaaay down on power)
#3. Poor starting in cold weather. (If not impossible)
#4. High cost/energy density.
#5. Heavy tank needed.
#6. Large tank needed.
#7. Hard to find compared to gasoline.
#8. Hard on valves.
#9. Takes a long time to fuel up.
#10. Vehicle cost a lot more if duel fuel.

Pretty easy to see who wins.

agesilaus wrote:

Yes... But I think I would rather have this than a EV truck that maybe able to pull your camper ~100 miles at best. Plus these guys claim they're able to maintain factory power.

Dream on if you think the ----- types will let you have one of these. They are busy attacking gas stoves right now after all.

They're a bunch of azz clowns.

at one time around here after comparing energy density and cost and fuel economy propane was noticeably cheaper even after conversion costs for gas engines if you put 10K miles or more/year on the vehicle. Some of my co workers who had 50+ mile round trips each day did the conversion and were happy with it. You still had to pay fuel tax on the propane. But then propane got more expensive so the advantage disappeared,

For a while folks with diesel trucks were doing a conversion where propane was injected into the manifold and diesel injected into the cylinders again, for cost advantage along with longer range (but with a propane tank in the back)

Propane can tolerate a much higher compression ratio than gas before detonation, so like alcohol, you can gain power IF the engine is designed for the higher compression and can take advantage of ignition timing. That gains power and economy.

Lots of stationary power generators and big backup generators run on propane, no worry about fuel going bad and the burn so clean oil life is much longer and they are easier to start.

Then there are dual or tri fuel portable generators. My honda 2200 is modified to run on gas, propane or NG. Propane or NG does have less power, but if I need it at home if the power goes out, running on NG give an infinite run time, no worry about how much gasoline I have. Run it on gas when camping.

Yes... But I think I would rather have this than a EV truck that maybe able to pull your camper ~100 miles at best. Plus these guys claim they're able to maintain factory power.

Dream on if you think the ----- types will let you have one of these. They are busy attacking gas stoves right now after all.

Schwan's Food Delivery trucks had OEM propane engines. All the drivers we had (GA, NC, SC & TN) all said the same thing. The trucks had little power. I don't know if it was due to gearing or the fuel or the engines. As for refueling, all our drivers were running routes that were far from the main depot. So they had a delivery truck that would drive out from the main depot and park until they stopped by to empty the delivery truck. They refueled at propane distributors or the satellite fill stations.