This is in reference to the EGR build that T Vago was presenting.

[RustyLugNut]

. . . when you can wake up and ogle pretty machines while sipping my coffee! Thanks pgfpro and iveyjh.

Good assessment report.

Originally Posted by pgfpro

So IMHO I can see where HHO could possibly help with combustion efficiency? If you can increase flames speed you can increase engine efficiency. Whats even more cool is with an increase in flame speed you could increase the compression of the engine (North Star Cad engine).
Also if you increase flame speed it would help a ton with lean burn.

So I don't have any testing with HHO but I can see where it could help. Now the big $$$ question is how much HHO and would it be cost effective???
I don't have a clue?

We should wait on the HHO as I am not sure how it would react in yours and iveyjh's build since you are both boosting. My experience with it is only in the unboosted balanced burn and lean burn regimes. In stoichiometric (balanced burn of lambda = 1) it caused detonation in an iron headed Dodge 5.9 l gas engine at a volume mix of 1:700 HHO/air. Again, I do not think it is all the hydrogen's doing. The oxygen produced during electrolysis often has O3 as a byproduct and the effect of that is much like you found in your N2O2 "experiment". I was in touch with an electrical engineering student in India who was doing graduate work on ozone production. He used a small Hoffman Apparatus (electrolyzer) to produce an oxygen stream to introduce into his ozone device. A test of the oxygen purity revealed that it already contained a small portion of O3. He further surmised the amount of ozone could be due to small amounts of impurities in his electrolyte. I am still unable to find the link to a paper by a government lab on ozone in combustion. The summary was that ozone in quantities as small as 40 parts per million could measurably accelerate the combustion rate of a hydrocarbon fuel. Again, that is parts per million.

[RustyLugNut]

Originally Posted by Daox

I don't think I would call a 7.7% gain very limited. As mentioned, there aren't a lot of mods that will bring you that kind of gain for a single modification. In smaller engines, which run at a higher load for a given speed, you should be able to see even higher gains I would imagine due to being able to run more EGR.

You are right in reference to what we can expect to find from the typical mod. I am speaking in reference to the overall picture of thermal efficiency (TE). An engine with 30% TE will reach a limit of 32-33% TE at increasing EGR at which point the combustion becomes unstable and torque falls off drastically. The SwRI paper makes it clear the 30% savings were at heavy loads where the cooled EGR was used to replace the overfueling needed to avoid detonation.

The thrust of my investigation lies in the lean burn regime. Instead of adding noncombustible EGR, I add more air that can still be part of the reaction. Now I add enthalpy. The addition of heat, pressure, turbulence and chemical seeding can allow us to run lean but strengthen the combustion to produce greater torque. Roughly a decade ago, College of the Dessert published a report on their use of bottled hydrogen in a ford V8 engine and used the wide flammability limit of hydrogen to run without a throttle. Tel Aviv University published a paper in the 1980 issue of Power Magazine and outlined the ability to sustain combustion in a methane/hydrogen mix with the addition of heat and turbulence to an air/fuel ratio of 100:1. All the Legos are there to build the Smokey Hot Vapor engine. With the aforementioned HCCI engine as a target, I think we can push past the 40% TE and approach the 50% TE with a gasoline engine. We may exceed that. We won't know until we try.

[Daox]

I have read a bit about how hydrogen effects combustion. I am aware that it increases flame speed, and is thus a great candidate to pair with lean burn to speed things back up and extend lean burn to even higher air/fuel ratios. I have yet to see someone actually put these two together in a car and run it though. There is also the issue with producing hydrogen onboard efficiently which I haven't seen addressed... ever. I'd like to see someone give it a shot though. If paired with variable compression, you'd have an amazing combo.

[RustyLugNut]

Originally Posted by Daox

I have read a bit about how hydrogen effects combustion. I am aware that it increases flame speed, and is thus a great candidate to pair with lean burn to speed things back up and extend lean burn to even higher air/fuel ratios. I have yet to see someone actually put these two together in a car and run it though. There is also the issue with producing hydrogen onboard efficiently which I haven't seen addressed... ever. I'd like to see someone give it a shot though. If paired with variable compression, you'd have an amazing combo.

. . . to affect combustion in the classical way. You are absolutely correct that we will not be able to efficiently produce it via on board electrolysis. But, as a seeding ingredient to affect the chemical kinetics, it can be effective. Studies on HCCI often use mixtures of hydrocarbons and hydrogen so that the chemical kinetics can be varied via fuel mix. Those studies use AFRs so lean, neither of the fuels should be able to burn when viewed in the classic sense, either individually or together. Both fall below the combustibility limits. But, when heat, pressure and turbulence are included into the equation, they detonate.

I include HHO in the discussion only because I would like to have an investigated answer for folks who drop in and ask. However, I surmise that it won't be needed in the end. Heat, turbulence, vaporization (added enthalpy) and pressure will be enough. And the turbo charger acts like a variable compression device. Oil Pan had a good discussion of that a long while back.

https://www.academia.edu/8209167/Basics_of_HCCI_engine

Here is a link that I hope allows a direct view of the presentation slides for HCCI. There isn't much discussion but the graphs give copious information. Especially telling is the pressure rise and ignition delay. If we could build an engine with "near HCCI" conditions, I propose the start of ignition via a spark would soon (micro seconds) incite ignition in the rest of the combustion chamber leading to rapid pressure rise. That is development further down the road, but I think iveyjh and pgfpro are closer than I am to answering the question.

[RedDevil]

I like the suggestion of combining (increased?) EGR with water injection.
I saw heat was a limiting factor on EGR flow.

I am confused though as why it has to be a true vapor.
I feel the coarseness of the spray can be an issue, of benefit or otherwise. Deliberately using tiny droplets instead of fine spray could help as they would evaporate more slowly, like after combustion instead of during, not hindring the combustion process too much but still add to the volume of the exhaust gas. But it is just an idea and I realize how much that depends on the other parameters (like revs, pressure, fuel mixture, temperature) to work or be detrimental.

I overstep my knowledge on this, but pray the corral will be mild to me.

[Xist]

Originally Posted by Daox

I have read a bit about how hydrogen effects combustion. I am aware that it increases flame speed, and is thus a great candidate to pair with lean burn to speed things back up and extend lean burn to even higher air/fuel ratios. I have yet to see someone actually put these two together in a car and run it though. There is also the issue with producing hydrogen onboard efficiently which I haven't seen addressed... ever. I'd like to see someone give it a shot though. If paired with variable compression, you'd have an amazing combo.

Could you imagine the science fair exhibit HydroJim could make with that?

Of course, he already made a lean-burn Jeep!

[oil pan 4]

Originally Posted by pgfpro

Some times you learn things from mistakes or in this case a nitrous solenoid leak

Have you tried running 2 nitrous solenoids in series?

[oil pan 4]

Originally Posted by RedDevil

I saw heat was a limiting factor on EGR flow.

http://ecomodder.com/forum/showthrea...ler-29085.html
I figure they could be used as EGR coolers, exhaust powered coolant warmers, intake air heaters, aftercoolers and so on.

[pgfpro]

Originally Posted by oil pan 4

Have you tried running 2 nitrous solenoids in series?

Nope.

This solenoid has been giving me problems since day one. I finally tossed it and replaced it with a newer one and no more issues.

[oil pan 4]

Problem nitrous solenoids are scary. I always figured people tossed them or rebuilt them at the first sign of trouble.