[pgfpro]

One of the companies I work for purchased a few Hydrogen generators for their fleet of vehicles. Some were used on Dodge diesel trucks and two others were used on some gasoline trucks. The ones on the diesels showed gains in mpg. The ones on the gasoline trucks showed no gains.

I can use one of the generators for free if I want to but I have know desire to go down this path. I haven't seen any improvements from them and I don't know of one person that has used one that has seen fuel economy gains.

Plus with my engine I feel there isn't much fuel left over to burn running as lean as 25:1

When it comes to burn rates I do agree that the idea is to have the flame speed as fast as possible but for fuel economy I don't see how this would help in a light load throttled condition. I actually tested this with very small amounts of N2O at light load low rpm.

What I found was when the engine is running lower rpm's a fast burn rate likes to kick the piss out of the piston, due to low piston speed. This is with even an optimum max cylinder pressure around 12 to 14 degrees atdc.

I will use Ben Strader's from EFI University analogy.

Think about piston and rod angle like pedaling a bicycle. Your best force on the pedal (or max cylinder pressure) will happen around 12 to 14 degrees atdc. If you start applying force earlier you actually have to much force closer to tdc and you are trying to force the pedal backwards. To late you don't have much force applied before bdc.

But back to a low rpm accelerated flame front. So you retard timing to get the desired 12 to 14 degrees pedal angle. IMHO you have a shorter amount of time and pedal angle to apply force. Its almost like trying to kick start your pedal. The bicycle doest accelerate that fast by this method. Now take the same amount of force and apply it over a longer duration with the same desired 12 to 14 degrees atdc max cylinder pressure or in this case pedal angle (slower flame front) now the bike accelerates faster or maintains its speed.

Now where a fast flame front works great is at a high rpm. Anything over
6500+rpm. At these rates the piston will out accelerate the flame front.

Example; With an convential burn rate you could just increase the ignition timing btdc so you will have your max cylinder pressure back to 12 to 14 degrees but you're increasing the chances of detonation with a longer crank angle power stroke(trying to push the pedal down when its coming up to tdc). Not good.

So to fix this we come up with fast burn technology heads. Now you can start the ignition timing later to avoid detonation and still have your max cylinder pressure at 12 to 14 degrees.

So as a fuel chemist you have to make the fuel work at lower rpm's with a slower flame front and at higher rpm's where a faster flame front is needed.