Foo - How fast does an injector inject?

How fast does an automotive gasoline injector function? Or I guess the appropriate question, what would the maximum speed be in general? Just looking for a ballpark estimate.
Thanks

Faster than you can say "Jack Robinson". :p :D

Engine rpm at redline / 60 / # of strokes = rough ballpark of duration of one injection in seconds.

How fast does an injector inject?At the injection rate. ya think?

don't get started on the woodchucks !

Really super duper fast.

Like HELLA fast.

****Taken from Wikipedia @ http://en.wikipedia.org/wiki/Fuel_injection



Calculate injector pulsewidth from airflow

First the CPU determines the air mass flow rate from the sensors - lb-air/min. (The various methods to determine airflow are beyond the scope of this topic. See MAF sensor (http://en.wikipedia.org/wiki/Mass_airflow_sensor), or MAP sensor (http://en.wikipedia.org/wiki/MAP_sensor).)

(lb-air/min) × (min/rev) × (rev/4-strokes-per-cycle) = (lb-air/intake-stroke) = (air-charge)- min/rev is the reciprocal of engine speed (RPM) – minutes cancel. - rev/2-revs-per-cycle for an 8 cylinder 4-stroke (http://en.wikipedia.org/wiki/4-stroke)-cycle engine.

(lb-air/intake-stroke) × (fuel/air) = (lb-fuel/intake-stroke)- fuel/air is the desired mixture ratio, usually stoichiometric, but often different depending on operating conditions.

(lb-fuel/intake-stroke) × (1/injector-size) = (pulsewidth/intake-stroke)- injector-size is the flow capacity of the injector, which in this example is 24-lbs/hour if the fuel pressure across the injector is 40 psi. Combining the above three terms . . .

(lbs-air/min) × (min/rev) × (rev/4-strokes) × (fuel/air) × (1/injector-size) = (pulsewidth/intake-stroke)Substituting real variables for the 5.0L engine at idle.

(0.55 lb-air/min) × (min/700 rev) × (rev/4-strokes-per-cycle) × (1/14.64) × (h/24-lb) × (3,600,000 ms/h) = (4.0 ms/intake-stroke)Substituting real variables for the 5.0 L engine at maximum power.

(28 lb-air/min) × (min/5500 rev) × (rev/4-strokes-per-cycle) × (1/11.00) × (h/24-lb) × (3,600,000 ms/h) = (34.6 ms/intake-stroke)

Injector pulsewidth typically ranges from 4 ms/engine-cycle at idle, to 35 ms/engine-cycle at wide-open throttle. The pulsewidth accuracy is approximately 0.01 ms; injectors are very precise devices.

For an accurate, visual representation, pull an injector from your engine, and have a friend rev it up while you look at it. It will spray gasoline all over and give you a first hand idea.

Never really tried to time one but if you use a stethoscope on one you can hear the injector opening and closing. You might be able to time it.

do you mean cyclic speed or flow rate?

showing my stupidity here, but doesn't the flow rate depend on the pressure with which the fuel is being pushed through the nozzle?

showing my stupidity here, but doesn't the flow rate depend on the pressure with which the fuel is being pushed through the nozzle?

Yes, exactly, the wider open the throttle position, the more gasoline will be sprayed into the cylinder.

Wouldn't it also depend on whether it is TBI, Tuned Port, or direct injectors?

TBI is essentially a continuous flow of fuel into a throttle body in top of the intake manifold and Direct is pulsed directly into the cylinder with a separate air entry system ;).....

I never did like TBI. I find it difficult to think of a reason for devolving away from carburetors.

How fast does an injector inject?


Faster than a woodchuck can chuck wood

Here's a bunch of injectors spraying.

http://www.youtube.com/watch?v=kHJSRpE5ok4

For an accurate, visual representation, pull an injector from your engine, and have a friend rev it up while you look at it. It will spray gasoline all over and give you a first hand idea.

Don't forget to hold the spark plug wire in your other hand.

Safety First!

I've used up to 96-lb/hr (1000cc/min) injectors on my car. Problem with such a high flow-rate is that in order to move the required fuel-volume out of a single hole pintle, it comes out pretty much as liquid stream. Not good for atomization, mixing with incoming-air and power-production. Using 6-hole disc-type nozzles really improved spray-pattern and atomization (less latency too), but it still wasn't good enough.

So I moved to dual 55-lb/hr injectors (per cylinder) in a staged configuration. The ECU runs one injector up to 80% duty-cycle. Then it holds that one at 80% and brings on the 2nd injector. By the time they're both running 80%, it'll increase flow from both of them to 100%. Using injectors above 80% duty-cycle is not recommend as it gives it too little time to cool off between squirts.


showing my stupidity here, but doesn't the flow rate depend on the pressure with which the fuel is being pushed through the nozzle?Yes, the flow-volume and flow-velocity an injector generates is also dependent upon the pressure-differential between the injector's inlet and outlet (inlet-outlet). The official "size" of an injector assumes a standardized 3-bar of fuel-pressure at the injector's inlet and 100% duty-cycle. However, that 3-bar of pressure is misleading. Even if you feed an injector 3-bar of fixed-pressure, that's not really the pressure-differential between the inlet and outlet. That's because the outlet end of the injector faces intake-manifold pressure, which changes constantly.

So at idle with 0.3-bar (absolute) in the intake-manifold, the injector is actually seeing 3bar-(-0.7bar vacuum) = 3.7 bar of pressure-differential. And under full-throttle with 0.8-bar in the intake, the actual pressure driving fuel is 3bar-(-0.2 bar vacuum)bar = 3.2 bar. As a result, a 10ms pulse of injector-open time during full-throttle has less pressure pushing fuel than the same 10ms pulse at idle. This makes fuel-volume calculations very difficult if you have to account for manifold-pressure all the time and have to re-adjust pulse-width accordingly.

Imagine an extreme case of turbocharging at say... 3-bar of boost (43.5psi). The 43.5psi of intake-manifold pressure at the injector outlet perfectly pushes back the 4.35psi of fuel-pressure on the injector inlet and you'd get ZERO fuel-flow at all when the injector opens :eek:

There's a clever way around this. That's to use automatic feedback to adjust fuel-pressure. The intake manifold-pressure is actually fed into the 3bar fuel-pressure regulator to automatically adjust its pressure. The reference-pressure is 0-psi (atmospheric) which causes no adjustments to the FPR's pressure-output. Vacuum in the intake will subtract from the FPR's fuel-pressure while boost above atmospheric will add to the FPR's output.

So at idle, the higher vacuum will cause fuel-regulator will put out 3bar+(-0.7bar) = 2.3 bar. The injector sees this pressure combined with vacuum in the manifold 2.3bar-(-0.7bar vacuum) = 3.0bar fuel pressure.

At full-throttle the regulator puts out 3bar+(-0.2bar) = 2.8bar. And the injector gets 2.8bar-(-0.2 bar vacuum) = 3.0bar fuel pressure. The variable-pressure feedback-adjusted fuel-pressure regulator thus automatically cancels out intake-manifold pressure and a 10ms pulse delivers identical fuel-volumes regardless of intake maniold pressure! :)



Seems like all this is putting the cart before the mule. What is it that you're trying to do? Define your objectives and desired-results first in concrete terms, and THEN try to figure out a way to implement it.

How fast does an injector inject?


Faster than a woodchuck can chuck wood

:rolleyes:

See post #4


:D

showing my stupidity here, but doesn't the flow rate depend on the pressure with which the fuel is being pushed through the nozzle?

No. Most FI systems are constant pressure systems. The pressure in the fuel rail remains constant, the longer the injector stays open, the more fuel it injects and vice versa. In Versa's post above, you can see that the pulse lasts from 4 to 35 ms from idle to FT.

No. Most FI systems are constant pressure systems. The pressure in the fuel rail remains constant, the longer the injector stays open, the more fuel it injects and vice versa. In Versa's post above, you can see that the pulse lasts from 4 to 35 ms from idle to FT.

yes, but the flow rate would still be dependent on the pressure, no?

:rolleyes:

See post #4


:D

:o:)

yes, but the flow rate would still be dependent on the pressure, no?Yes it does. Flow-rate is dependent to the square-root power of pressure-differential between the inlet vs. outlet ports of the injector. So if you increase pressure by 2x, flow increases by sqrt(2)= 1.4x . There's a misconception about FI systems using constant-pressure, they actually are calibrated for constant pressure-differential between the injector inlet & outlet. This function is served by the variable-pressure FPR and that allows the ECU programming to assume a constant pressure-differential. Thus a 30ms pulse-width can always be assumed to deliver X-volume of fuel regardless of manifold-vacuum/boost. Here's some pictures of FPRs on the market:

Stock Bosch 3-bar FPR used on a majority of German cars:
http://www.paragon-products.com/photos/PP0.280.160.287-2.jpg

Aftermarket FPRs:
http://www.jcwhitney.com/wcsstore/jcwhitney/images/imagecache/G_15681G_SW_1.gif
http://www.jcwhitney.com/wcsstore/jcwhitney/images/imagecache/G_15680G_CL_1.jpg

The fuel-pressure regulator works by being a restriction at the exit end of the fuel-rail. The FPR is bolted to the fuel-rail and the inlet on the side of the FPR is hidden between the two bolt-holes. The large threaded outlet at the end goes to the fuel-line back to the tank. The tiny vacuum nipple is hooked up to the intake-manifold to get the adjustment-pressure based upon manifold-vacuum.

These aftermarket FPRs also have adjustable initial-pressure with the threaded bolt with locking nut. These set the desired pressure at with 0 vacuum/boost (engine off or vacuum-nipple vented to atmosphere). Then the vacuum-nipple will typically adjust the actual output pressure anywhere from -10psi to +30psi in order to maintain a constant pressure-differential between the injector's inlet & outlet ports. :)

It's also easy enough to verify that fuel-pressure in the rail changes with throttle-position and manifold-vacuum. Just hook up one of these gauges at the end of teh rail:

http://www.lindseyracing.com/pics/vdofpg1.jpg

At idle, manifold-pressure is typically the lowest (most vacuum) and you'll see lowest-pressure on the gauge. Rev it up some and vacuum decrease (more pressure in manifold) and pressure increases. If you've got a turbo car, add boost on the road and you'll see pressure increases even more. All the while, the pressure-differential across the injector remains constant.

Slightly OT, but a damn good read for anyone who hasn't seen it before:

# One Top Fuel dragster's 500-cubic-inch Hemi engine makes more horsepower than the first four rows at the Daytona 500.

# A stock Dodge Hemi V-8 engine cannot produce enough power to drive the dragster's supercharger.

# With 3000 CFM of air being rammed in by the supercharger on overdrive, the fuel mixture is compressed into a near-solid form before ig-nition. Cylinders run on the verge of hydraulic lock at full throttle.

# At the stoichiometric 1.7:1 air-fuel mixture for nitromethane, the flame front temperature measures about 7000 degrees Fahrenheit.

# Nitromethane burns yellow. The spectacular white flame seen above the stacks at night is raw burning hydrogen, separated from atmospheric water vapor by the searing heat of the exhaust gases.

# Dual magnetos supply 44 amps to each spark plug. This is the output of an arc welder in each cylinder.

# Spark plug electrodes can be totally consumed during a single pass. After half-distance, the engine is dieseling from compression plus the glow of exhaust valves at 1400 degrees Fahrenheit. The engine is shut down by cutting the fuel flow.

# If a spark plug fails early in the run, un-burned nitro can build up in the affected cylinder and explode with sufficient force to blow the cylinder head off in pieces or split the cylinder block in half.

# In order to exceed 300 mph in 4.5 seconds, dragsters must accelerate at an average of more than 4 g's. In order to reach 200 mph before half-distance, the launch acceleration approaches 8 g's. A Top Fuel dragster reaches more than 300 mph before you have completed reading this sentence.

# With a redline that can be as high as 9500 rpm, Top Fuel engines turn approximately 540 revolutions from light to light. Including the burnout, the engine needs to survive only 900 revolutions under load.

# Assuming that all of the equipment is paid off, the crew works gratis, and nothing breaks, each run costs an estimated $1000 per second.

# The current Top Fuel dragster elapsed time record is 4.441 seconds for the quarter-mile (October 5, 2003, Tony Schumacher). The top-speed record is 333.25 mph as measured over the last 66 feet of the quarter-mile (November 9, 2003, Doug Kalitta).

# Putting all of this into perspective: You are driving the average $140,000 Lingenfelter twin-turbo Corvette Z06. More than a mile up the road, a Top Fuel dragster is staged and ready to launch down a measured quarter-mile as you pass. You have the advantage of a flying start. You run the Vette up through the gears and blast across the starting line and past the dragster at an honest 200 mph. The "tree" goes green for both of you at that moment. The dragster launches and starts after you. You keep your foot down, but you hear a brutal whine that sears your eardrums, and within three seconds, the dragster catches you and beats you to the finish line, a quarter-mile from where you just passed him. From a standing start, the dragster spotted you 200 mph and not only caught you but nearly blasted you off the road when he passed you within a mere 1320 feet.

I would like to know a typical pulse length that an ECU sends to an injector because I am considering building a circuit that can scale this pulse to be longer. This elongated pulse could possibly provide power to a solenoid valve, or even a Ford IAC valve. It'll provide the power to something, I Just need to find out what.

I would like to know a typical pulse length that an ECU sends to an injector because I am considering building a circuit that can scale this pulse to be longer. This elongated pulse could possibly provide power to a solenoid valve, or even a Ford IAC valve. It'll provide the power to something, I Just need to find out what.Dude, you're re-inventing the wheel. Someone's already done this work and have a product on the market. Contrary to what most people think, the "on" pulse of an injector is NOT a square-wave:

http://www.picotech.com/auto/waveforms/graphics/injector_multi.png
http://www.picotech.com/auto/waveforms/graphics/injector_single_1.png
http://www.picotech.com/auto/waveforms/graphics/injector_single_2.png
http://www.picotech.com/auto/waveforms/graphics/injectorfordsinglepoint.gif

And you don't want a longer pulse-width for the stock injectors, you want it shorter due to the lower amount of atmospheric air entering the engine. The incoming H2/O2 mix is already balanced for complete combustion, so you don't have to worry about that.

If you're going to be driving an additional device, you'll need an amplifier. The current demands are typically 4-8 amps for an injector and the stock drivers in most ECU boxes only have enough capacity for the stock injectors. Also at 6000rpm redline, there's only 32ms of injection time between pulses. You need a device that can turn ON quickly in less than 3-5ms like a typical peak&hold injector. Longer time than that means you'll waste a lot of time waiting for the damn thing to open and have very little time left to move stuff through. That's why peak&hold injectors are preferred for high-performance application than the slower-opening saturated injectors.

Well I was just going to have the ECU pulses trigger a transistor, which will enable current to flow from another power supply.

Thanks for that link, that's exactly what I was wanting to know.

By the way, what do you think of a gas carburetor, such as that made by IMPCO? It's designed to mix two gases. I think that propane powered forklifts use this, and that CNG vehicles use these. I could probably get away with the smallest carb they have.

Why a carb? It's for vapourizing a liquid and mixing it with air. Anything you add to the intake of your car will cause restriction and limit total air-flow. Injecting it directly into the intake-manifold like nitrous as you have now is fine.

All this is irrelevant if you can't even generate significant amounts of H2. Let's say that you're on the high-side of the range of the device that claims 50-70L/hr. How about 72L/hr?

- 72L/hr = 1.2 L/min

Your 1.6L engine sucks up 1.6L every 2 revolutions of the engine. So at 1200rpm idle, you're consuming:

- 1200rpm/2 = 600 intake-strokes/min * 1.6L = 960 L/min

At maximum capacity, your hydrogen-generator can contribute at most 1.2/960 = 0.125% to the overall mixture at idle or about 0.0313% at 4000rpms. I doubt you'd need to do much tinkering with programmable injection devices. Just keep it plumbed in full-time like it is now and work on a way to increase H2-production by at least 100x before you'd have to worry about 3D-programmable injection and adjusting the timing map. ;)

But I am not trying to run my car on pure hydrogen, only trying to supply a small but consistent amount. I'll screw in my pressure gauge and find out how much gas I am generating sometime soon.

Yeah, I would think that you'd want at least 10% supplementation. Any less than 10% and any measurable and usable data will disappear into the fuzzy atmospheric variables like air-temp, air-density, relative humidity, elevation, etc. But to run at 10% hydrogen just at idle, you'll need 80x more than you have now. And to keep that 10% supplementation constant up to redline, you'll need to generate 640 Liters per MINUTE.

This is starting to sound a lot like the electric supercharger idea... ;)


To measure gas-generated, you really have to do the same kind of test as the EPA for certifying non-US cars. Gas-bag the exhaust. So hook up a giant deflated balloon to your apparatus and measure the volume and weight of gas produced in say... 10-minutes. Then you can figure out production-capacity for the thing.

BUt that 10% supplementation is just your guess. That company which markets these generators claims timing can be advanced 2-4 degrees just on that 50-70L figure. I need to find out when electrolysis becomes a net loss due to alternator load.

BUt that 10% supplementation is just your guess. That company which markets these generators claims timing can be advanced 2-4 degrees just on that 50-70L figure. I need to find out when electrolysis becomes a net loss due to alternator load.Well, SAE-standard atmospheric corrections for dynos can vary as much as 10% from day to day. Without these corrections for air-density, temps, elevations, etc. the same car can exhibit -/+ 5% variations in power-output from day to day. Many ricer guys will cheat and look around for a dyno with manual corrections and find a good cold day to run and prompt for no-corrections when the dyno-chart is printed. That's why I'd say you need to make a difference of 10% or more when doing mods for the gains to be statistically significant.

It is always a loss when using the alternator to drive electrolysis. The alternator itself is about 80% efficient. Then take that power and figure out exactly how much hydrogen you're producing. Then measure exactly how much more power or gas-mileage you got. And you'll see that it's always a loss.

Only way to extract more energy out of it is if you used external energy outside of the car. Like generate the hydrogen and store in a tank on the side of the house by stealing your neighbor's electricity. You're trying to make your sailboat go faster by blowing on it as you're sitting in the boat... ;)

TO measure gas production,
could I not just connect the pressure gauge to the NPT threaded port on my electrolysis chamber, run the unit for a minute, record the pressure, and then do the math? I know the volume of my tank.

Only way to extract more energy out of it is if you used external energy outside of the car. Like generate the hydrogen and store in a tank on the side of the house by stealing your neighbor's electricity. You're trying to make your sailboat go faster by blowing on it as you're sitting in the boat... ;)


That's actually not true. Even though it's a loss in that electrolysis is a net loss, the fact the GAIN from having hydrogen mixed into the fuel mixture makes it a NET gain. There is a point at which the alternator load overcomes the benefit from the hydrogen content.
By your logic, hybrid vehicles which use an electric motor would not make them more fuel efficient.
Remember:
I am not trying to extract more energy, I am trying to use the energy that I have more efficiently.

I am not trying to extract more energy, I am trying to use the energy that I have more efficiently.Then you're looking at all the wrong places. Look at all the areas where the heat-energy of combustion is loss before the wheels are driven. About 40-60% of the heat is sucked into the colder metal and coolant jacket of the engine. Only the remaining is used to drive the piston down. And then there's huge frictional loses in the rings. Honda's 8-valve oval-piston engine was extremely innovative in this regard as it had lower ring-friction versus flow & power-output than an equivalent round-piston engine.

Look into the frictional losses at the crank and con-rods. Now you've got less than 40% of the combustion-energy even making it out of the engine. And the gearbox itself loses about 12-25% and automatics take up another 10% on top of that. A hybrid with 80% efficient motor directly attached to the drive-wheels will still be better than a gasoline engine at less than 30%.

What you're missing is that the extra drag on the alternator will not be offset by the additional power you get from the hydrogen combustion. If it takes an extra 1 hp to drive the alternator, you will certainly get less than 1 hp of additional power out of the engine.


Another part you're missing is that you're completing a full-cycle with the hydrogen. You will end up with a net loss. Whereas the energy extracted from fossil-fuels is not a full-cycle and not a net-loss. That's because the major energy-intensive part of putting energy into creating the hydrocarbon bonds comes from million of years of sunlight and then billions of pounds of pressure from the plates of the earth. Us humans didn't have to put any of this energy into creating oil. Even the energy required to extract the oil, refine it, ship it to gas-stations is miniscule compared to the amounts of free-energy that's been bound into those molecules.

You need to quantify your experiment. There's no way you can see that it's a net loss without hard concrete numbers. That's like saying, "increasing the numbers of dancing angels on the head of a pin by 25% will increase the productivity of my sweatshop workers". Without any way of actually measuring the numbers of angels, you can't possibly make that kind of a statement.

BTW, pressure in a vessel has nothing to do with it's flow-rate or volume. My argon-tank is sitting here with 1000psi in it and nothing's flowing. Even when I'm using it for welding, the pressure in teh tank is still 1000psi. Pressure in a tube is even more troublesome because of the Bernouli effects. Higher flow-rates and velocities will result in lower-pressures. But it's not linear. And the same pressure in a 1" tube vs. a 1/4" tube represents completely different flow-rates as well. You can get gas-flow gauges, but they're typically only accurate for high flow-rates and high-volumes to seal the displacement chambers.

Also if you have a fixed-volume chamber, you have to account for the original condition and break it down by partial vapour-pressures of the existing gases. Waver-vapour will be a significant contributor based upon temperature. Pressure changes with electrolysis above will change the solubility of gases in the liquid itself. You'll have to somehow figure out how much of the generated gases are remaining dissolved inside the liquid based upon pressure. That's why it's easier to maintain as many control constants as possible such as temperature and pressure. The only thing that should change is volume. Just capture that volume and measure it.

Could you run the electrolysis off of something other than the alternator? Say, maybe affixing a solar panel to your car and then running it off of that?

Could you run the electrolysis off of something other than the alternator? Say, maybe affixing a solar panel to your car and then running it off of that?Comes down to watts-per-sq.ft. of solar panels on a car. He's already consuming 240-watts of power and needs to create at least 100x more. If his entire car's surface was plated with solar-cells, I doubt he'd be able to create the existing 240-watts he's consuming.

But the hydrogen is not meant to replace the gasoline. It's merely a fuel additive that I produce on demand which has the ability to allow the existing fuel to be used more efficiently. Your statement about the power gained from hydrogen combustion not offsetting the power taken to drive the alternator is true; if I was to try and run just on hydrogen.

Just as with a conventional hybrid, the ICE charges the battery which supplies power for the vastly more efficient electric motor. It's not creating energy, it's using it more efficiently.

If I wanted to run my car solely on electrolysis generated on demand, well, it would not run of course. That's because electrolysis is something like 30% efficient in itself. But there's a cut off point.
If one was to plot a graph with the following:

Fuel economy gains by injecting some hydrogen generated via electrolysis vs alternator drag losses.

They would find that there's that point at which the combustion efficiency gains from hydrogen are offset by alternator load. That point is NOT at the 15 amp mark though.

Quoted from http://www.thermo1.com:

On demand hydrogen boost system DO WORK and they DO NOT violate any laws of physics! Hydrogen boost systems work for one simple reason . . .

Adding a hydrogen-oxygen mix to the fuel system in an internal combustion engine increases the combustion of the gasoline (or diesel) due to the high volatility/BTU of hydrogen-oxygen mix. This can be compared to putting a super high grade of gasoline in your engine. You get better overall performance, increased horsepower and gas mileage. Yes, the devices do use electrical power from the engine that is ultimately created by the fossil fuel, but the gain in efficiency of the engine exceeds the energy loss from generating the hydrogen-oxygen mix. The increase in horsepower and gas mileage comes from better combustion of the gasoline, which the hydrogen-oxygen mix helps to achieve. Only about 15% of the available energy in gasoline is converted to mechanical energy in an internal combustion engine. Better combustion means more of the available energy in the gasoline is converted to mechanical energy and that has nothing to do with creating energy or violating any laws of thermodynamics!


I will have concrete #'s through my own experimentation soon enough. I think that the biggest mistake people make when they hear about this, is that they assume the individual is trying to run a hydrogen on demand system in which the hydrogen is intended to REPLACE the gasoline.

google "hydrogen booster".
Also, hceck youtube. There's videos where the owner will explain their setup.

Oh, if you're interested in some pretty unusual reading, check this out:
www.aero2012.com/en/documents/Stan_Meyer_Full_Data.pdf

BUt that 10% supplementation is just your guess. That company which markets these generators claims timing can be advanced 2-4 degrees just on that 50-70L figure. I need to find out when electrolysis becomes a net loss due to alternator load.

You won't want to advance the spark with hydrogen, unless you're ******** from MBT and think you'll have a higher effective octane with hydrogen addition. Under most operating conditions you'll want to take away spark with hydrogen supplementation.

The alternator itself is about 80% efficient.

Optimistic. FYI, I think he wants better results due to the better combustion properties of hydrogen.

This can be compared to putting a super high grade of gasoline in your engine.

Incorrect.


You get better overall performance, increased horsepower and gas mileage.

Possible.

Only about 15% of the available energy in gasoline is converted to mechanical energy in an internal combustion engine.

Quite pessimistic, and irrelevant.



Better combustion means more of the available energy in the gasoline is converted to mechanical energy and that has nothing to do with creating energy or violating any laws of thermodynamics!

True.

Why wouldn't I want to advance the timing? If a hydrogen containing mixture can ignite faster, it won't need that extra time available by 15 degrees before TDC.

...Thus you want to ****** timing. If you speed up combustion, you bring the spark closer to TDC (later spark), which, somewhat non-intuitively, is actually the opposite of 'advancing' the spark.

damn, I always get it mixed up. I'll never remember it.
That's why I always say "Bring closer to TDC". I thought I'd play it risky and use the proper terminology :p

Wow Danno, you're really into this. I was all set to come in and list injector open times I was familiar with, but it looks like you've got it thoroughly covered.

A decent bit of learning in this thread.

Optimistic. FYI, I think he wants better results due to the better combustion properties of hydrogen.yeah, let's say that burning 2-million oxygen molecules with hydrogen yields more heat than 2-million oxygen with gasoline. The absolute most amount of energy he can extract from that combustion will be EXACTLY the energy it took to break apart 4-million water-molecules. Problem is, it will still end up giving him less than that energy by the time that power gets to the ground. And certainly than that energy will make it to the front crank-pulley to re-drive the alternator to generate electricity. Certainly not enough energy to generate break another 4-million waters apart. It's a net-loss in any of the paths that energy can travel after combustion. This is why hydrogen fuel-cells are seen as a more efficient way to extract energy out of hydrogen oxidation.