Time to fire up my old Hydrogen generators

[TheEnemy]

But that is adding an outside source of energy, and will skew your results.

[BLSTIC]

Yes, but it will provide information on whether or not the small amount of hydrogen that can be made with a cars electrical system makes a difference. If I cannot make a difference with a separate power source, I certainly cannot when the car is being loaded by the alternator. And tbh, an external power source is easier and safer for an idle test than risking overloading the alternator (the current draw of one of my designs is limited by the feed wires and nothing else. Granted a lot of it is steam and not H2/O2 though...).

If it shows promise while idling, I'll set the electrolyte concentration (and so current) low enough for the alternator to reliably handle and see if it has any effect with the system properly installed and driving. It's not the test to end all tests, it's just a backyard hack job to test for ANY effect. I'll leave the detailed, lean burn cruise, programmable management stuff for later.

[gone-ot]

8.345 lb/gal @ 60ºF = water
6.073 lb/gal @ 60ºF = gasoline

...does HHO offset the 37.4% weight-penalty of water vs. gasoline?

[BLSTIC]

Well lets see. The project car weighs about 1100kg (incredibly light by modern standards). The hyrogen system weighs 10kg all up, absolute max (this is bubbler and electrolyser, both full of water. No automatic filling system. Wiring weight is negligible). This is around 1% of the mass of the car. Assuming zero energy recovery (through longer coast distances) it would take 1% more energy to accelerate the car, and nothing to keep in moving (1% change in mass would be undectible when it comes to rolling resistance). Under a worst case scenario (such as continous accelleration, or uphilll) the system will use 1% more fuel through mass alone.

If it makes 1% difference in economy. Even if I carried around an extra 20L of water (standard jerry can size) the MAXIMUM weight induced penalty would be 3%.

I would say that if the system changes combustion at all it will be worth the weight penalty.

That said, you all have to wait (until after I have converted my prelude loom from OBD1 to OBD2b plugs so I can use the (not so) plug in link that's in the shed) for results

[ChazInMT]

Lets not lose sight of 3 basic principles here. 1) We aren't making that much gas really. 2) It takes a lot of energy to make the extra fuel. 3) It defies the laws of physics if it were to even be a break-even system, much less one that improves mileage.

Once again I remind all of us here that the amount of actual fuel produced here is very small, it takes hours to make a quart of water into its gas constituent parts of hydrogen & oxygen, and since gasoline is primarily hydrogen fuel, and a gallon of gasoline makes a gallon of water, you'd be lucky to add 2% of fuel to the engines fuel demand. And the hydrogen created isn't some sorta miracle fuel, it's just hydrogen.

Drawing even 35 amps to make hydrogen requires 1/2 horse power to create, and with a 25% efficient engine, and 80% efficient alternator, you’re talking needing 2.5 horsepower to make the 1/2. Rough numbers, but you get the idea. 2.5 HP or 10% of the engine power to make 2% more fuel.

It just adds up to not gonna help. There is no "maybe it will help a little", cause if it even broke even, it would be the definition of a perpetual motion machine. I think we're all a little too smart to believe in perpetual motion aren't we? Maybe just tiny bit too smart? That’s all it takes.

Just Say No! to perpetual motion notions.

[BLSTIC]

The side of the fence I currently sit on (until after my tests anyway) is that if the engine is 25% efficient (if not less in most cruise situations), 75% of the engergy must be wasted.

We know that energy is at least partially recoverable, because raising the geometric compression ratio (really the expansion ratio is the important bit) results in more full load power, and economy in cruise situations, without a similar (percentage-wise) increase in air and fuel flow. We also know that unless the timing is at MBT, we can extract more power from a given charge simply altering ignition timing (knock limited of course, but water injection can soon solve that, without adding any extra fuel). Again, we also know that improving vaporisation (on systems like carbies that don't do such a good job of it) can improve economy, power, and emissions with zero change in airflow.

I'm just trying to release that energy chemically rather than mechancally.

That said, I completely agree with points 1 & 2. And it has become time for me to put my theories to the test, and gain some insight (and credibility) by accurately reporting on my test for #3, whatever the outcome may be.

Personally I have my hopes, doubts, and theories about it all, and I have nothing riding on whether it works or not. It's a scientific curiousity in me that says 'you have the parts, the knowledge, the time, and the inclination to try this, why not do it?'.

There's also a great many people with theories as to why/whether it will or will not work, a few people scamming, and very few people who are willing to go through their tests objectively.

If it works at all I'll eventually be putting this on a modern car, on a dyno with all relevant information recorded (air-fuel ratio, ignition timing, injector duty cycle, 4-gas analyser if they have one) for a test and tune session. Whether I get to that point is doubtful, but I have to try.