Re: Hydrogen-Boosted Internal Combustion Engines -- Scam Or Not ???

jim wrote:

Steve wrote:
Matt wrote:
jim wrote:

Hydrogen enrichment can also help overcome the problem that hydrocarbons
burned in spark ignited engines don't burn completely if there is more
air
than stoichiometric.
You're saying that with a leaner mixture the fuel burns less completely
than with a richer one? I can hardly believe that.
Yes and no. When running lean, there is a much higher probability of
mis-fire. If the mixture does indeed light off, it will burn very hot
and clean (apart from high nitrogen oxides). But the high probability of
misfire tends to kinda offset the gains.

I would say usually there are no gains any way. Any perception that running lean
burns cleaner is because the catalytic converter has more oxygen to do its job.
Without the cat CO and HC start to go up as soon as the engine goes lean.


ITs all a matter of degree. Going just a few percent lean of stoich lowers HC and CO even without a cat. Going further does what you say.


Being a Chrysler guy and having lived through the "Lean Burn" years, I
can say that the basic idea is sound enough but implementation is a bear
(and especially bad when trying to do it with a carburetor instead of
EFI). Lean-tuned engines will turn in very good fuel economy,

I never heard of anybody that got good gas mileage with the mid to late 70's
chrysler lean burn technology.

Then you didn't know them when they were working right. I was there when they were new and very common. 23 MPG out of a square brick of a v8 Fury was no slouch in those days and I've done just that routinely back in the day. The best of all was the lightweight slant-6 "feather Duster" that could and did turn in real-world 30+ MPG on the highway. The whole problem is that it wouldn't STAY that good without a lot of care, particularly the ignition side of things.




and it can
be done without sacrificing too much performance IF you can enrich
sufficiently on demand.


Well sure if all you do is run lean when there is no load on the engine - like
when you are coasting up to the next red light.

Only half the gain. You can run a few percent lean under any light-load condition- say cruising at a steady 65 mph. Modern EFI engines do this quite effectively, they just don't advertise it in the sales literature. The savings add up.


That part is correct and that modification usually results in an immediate 5-10
mpg jump in gas mileage as well as improved driveability.

No and yes (assuming the LB was WORKING when replaced.) LB systems had mediocre driveability even when working perfectly (there was always an annoying dead spot as you begin to roll on power following steady-state cruise, such as coming to the base of a hill). But they were nothing if not efficient when working. 5-10 MPG jump!?!? FORGET that, unless the thing was horrifically out of tune (which, granted, many were when these things started to get replaced.)

And FYI, after "Lean Burn" became a dirty word and negative marketing in the late 70s, they did stop putting the Lean Burn stickers on the valve covers. But the same engine management system was used until the last M-body went out of production in 1989, and the M-bodies were quite efficient for such a large and boxy vehicle.
.

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