Heated Fuel

[Christ]

No input on whether it would help or not, but a pretty easy way to make sure your fuel is at least reaching coolant temps:

Use a radiator from an automatic, clean the transmission fluid line input/output by flushing, then route your fuel lines through that area.

This will ensure that your fuel reaches something close to the temps of the coolant, at least, which is a huge increase from the ambient temp that it is when it's being pushed through the lines.

Heating the fuel rail may not be good enough, since the fuel is only actually there for a very short time... it may not be long enough for heat transfer to actually occur, whereas in a larger apparatus, such as a transmission cooler, heatsoak will be more likely to occur.

[blueflame]

My carby Citroen AX has 2 coolant hose's that heat the base of carby. I had a 1600 crossflow ford that used to heat the intake manifold with coolant from the head.

My engine has just starting to predetonate a little when going up hills with the warmer weather here in NZ. Timing is well advanced for economy.....

I will need to lower my air intake temp a little for longer trips on hot days or avoid hills, shorter journeys are okay.

We have a lot of Taxis and cop cars running on liquid petroleum gas, lpg or propane. It does save money in fuel costs, though requires different ignition and tuning to run as good as petrol.

CNG or compressed natural gas is really cheap and low in emissions, but down in power. Service stations providing CNG were pressurized to quit supplying CNG around 10 years ago. Shame, we have tons of it here.

[dremd]

Someone made a point that propane would show the same gains as heated fuel.
Before using that as a data point we should compare the btu/gallon for propane against gasoline.

[Christ]

Originally Posted by EIA Energy Kids Page

BTU Content of Common Energy Units
1 barrel(42 gallons) of crude oil = 5,800,000 Btu

1 gallon of gasoline = 124,000 Btu

1 gallon of diesel fuel = 139,000 Btu

1 gallon of heating oil = 139,000 Btu

1 barrel of residual fuel oil = 6,287,000 Btu

1 cubic foot of natural gas = 1,031 Btu

1 gallon of propane = 91,000 Btu

1 short ton of coal = 20,754,000 Btu

1 kilowatthour of electricity = 3,412 Btu

Note that an engine optimized for propane could see gains, but running a gas engine on propane will most certainly see losses.

[Christ]

Originally Posted by blueflame

My carby Citroen AX has 2 coolant hose's that heat the base of carby. I had a 1600 crossflow ford that used to heat the intake manifold with coolant from the head.

This is true of most modern cars.. a large number of them have coolant running in or near the throttle body, carb base, intake manifold, etc.

FWIW, it's not there to help with emissions or power, it's there to stop the throttle plate from sticking in cold weather, at least when OEM equipped that way.

[dremd]

Originally Posted by Christ

Note that an engine optimized for propane could see gains, but running a gas engine on propane will most certainly see losses.

But for our purposes here what we need to know is what losses are seen in the real world. If losses are less than the btu differance; then there might be gains to be had with fuel vaporization.

Does everyone follow me?

[dremd]

Originally Posted by Christ

No input on whether it would help or not, but a pretty easy way to make sure your fuel is at least reaching coolant temps:

Use a radiator from an automatic, clean the transmission fluid line input/output by flushing, then route your fuel lines through that area.

This will ensure that your fuel reaches something close to the temps of the coolant, at least, which is a huge increase from the ambient temp that it is when it's being pushed through the lines.

Heating the fuel rail may not be good enough, since the fuel is only actually there for a very short time... it may not be long enough for heat transfer to actually occur, whereas in a larger apparatus, such as a transmission cooler, heatsoak will be more likely to occur.

Don't forget to take in to account if the fuel system has a return or not ( most fi cars do) in which case you are flowing much much more fuel than the engine is using.

[Christ]

Originally Posted by dremd

But for our purposes here what we need to know is what losses are seen in the real world. If losses are less than the btu differance; then there might be gains to be had with fuel vaporization.

Does everyone follow me?

I understand what you're saying, but I don't think you're grasping that you can't compare gasoline to propane in this way...

Gasoline and Propane have two differing BTU/volume levels, they have two different densities, and you're attempting to compare apples to oranges here.

The actual comparison will have more weight in research terms if you're using the same fuel in two forms, since all else remains unchanged.

Liquid gasoline vs vaporized gasoline, in the same engine,

Not liquid gasoline in a gasoline engine vs. vaporous propane in a gasoline engine.

[Christ]

Originally Posted by dremd

Don't forget to take in to account if the fuel system has a return or not ( most fi cars do) in which case you are flowing much much more fuel than the engine is using.

I accounted for that in my head... the return system is such that the fuel will have cooled by the time it reaches the tank, and even if it hasn't, a tank full of 80* fuel being squirted with a jet of fuel at less than 200* isn't going to change an appreciable amount.

The best that would happen is a few degree's change, and it will only help the case where the radiator is heating the fuel to the same temps as the coolant.

[dremd]

Originally Posted by Christ

I understand what you're saying, but I don't think you're grasping that you can't compare gasoline to propane in this way...

Gasoline and Propane have two differing BTU/volume levels, they have two different densities, and you're attempting to compare apples to oranges here.

The actual comparison will have more weight in research terms if you're using the same fuel in two forms, since all else remains unchanged.

Liquid gasoline vs vaporized gasoline, in the same engine,

Not liquid gasoline in a gasoline engine vs. vaporous propane in a gasoline engine.

I *believe* that I am grasping it.

I'm trying to compare efficiencies of a system, so I'm taking energy in and comparing it to energy out.

Agreed that the experiment is crude, and ignores other variables like octane and flame speed, but it is a data set which should be easy to obtain and should be easy.

If someone was to convert say a generator from RUG to LPG they would only modify the Carb. inlets.

So if their fuel economy is X on RUG and Y on LPG then
Compare X/Y TO 124,000 btu/91,000 btu.


Reason I used generator is because a buddy of mine has a dual Fuel (LPG/RUG) generator and I'm sure he keeps records on fuel consumption.

NOTE: I have no stake in this argument, I just saw a comment and tried to add *some* science/ data to the point.
Personally I'm of the opinion that everything should either be electric, or compression ignition.