Myth Busters SUCKS! (HHO mod, does it work?)

[cfg83]

Hello -

(Sorry if this has already been posted)

This is from the 1977 NASA document :



Here's the (very old) engine they used :



You can read it here :

EMISSIONS AND TOTAL ENERGY CONSUMPTION OF A MULTICYLINDER PISTON ENGINE RUNNING ON GASOLINE AND A HYDROGEN-GASOLINE MIXTURE
http://ntrs.nasa.gov/archive/nasa/ca...1977016170.pdf

CarloSW2

[Christ]

Great article find, Carlos!

[dwtaylorpdx]

Interesting, but then you have to ask, have they learned anything new since 1977?

In 1977 it was carb or mechanical fuel injection, no O2 and very few service stations had exhaust gas analyzers. Yet we somehow got by... lol

Dave

[pgfpro]

Originally Posted by Christ

Piston speed isn't necessarily determined by engine speed, and the piston can fall away from the expansion of gasses at MUCH lower speeds than 6500 RPM. It's also dependent on stroke length.

I guess I should have been more specific.

In my post I was referring to two engines of the same design and a average piston speed.

An engine with a 85mm stroke @ 2400rpm will have a mean piston speed of 22.31 ft/second.

This same engine at 6500rpm will have a mean piston speed of
60.42 ft/second.

Now according to Willard W. Pulkrabek book "Engineering Fundamentals of the Internal Combustion Engine" the average combustion flame speed of typical modern SI engine will have a flame speed mean of 82 ft/second @ 1000rpm.

At only 3000rpm the flame speed will increase to 246 ft/second.

As engines rpm increases the intensity of turbulence, swirl, squish, and tumble all increase, resulting in a faster flame speed.

Also with a modern fast-burn combustion chamber engine you will see a 95% burn at 45 degrees crank angle @ 3000rpm.

[Christ]

Originally Posted by pgfpro

I guess I should have been more specific.

In my post I was referring to two engines of the same design and a average piston speed.

An engine with a 85mm stroke @ 2400rpm will have a mean piston speed of 22.31 ft/second.

This same engine at 6500rpm will have a mean piston speed of
60.42 ft/second.

Now according to Willard W. Pulkrabek book "Engineering Fundamentals of the Internal Combustion Engine" the average combustion flame speed of typical modern SI engine will have a flame speed mean of 82 ft/second @ 1000rpm.

At only 3000rpm the flame speed will increase to 246 ft/second.

As engines rpm increases the intensity of turbulence, swirl, squish, and tumble all increase, resulting in a faster flame speed.

Also with a modern fast-burn combustion chamber engine you will see a 95% burn at 45 degrees crank angle @ 3000rpm.

So you obviously know your stuff on this... knew you did, by the way.

Small displacement long stroke, or high displacement short stroke? (Opinion) (Number of cylinders fixed to 5, for the sake of removing a variable.)

[pgfpro]

Originally Posted by Christ

So you obviously know your stuff on this... knew you did, by the way.

Small displacement long stroke, or high displacement short stroke? (Opinion) (Number of cylinders fixed to 5, for the sake of removing a variable.)

This is based on a 80mm bore with a 85mm stroke.

[Christ]

No, I was asking for your personal opinion on which one you'd rather have -

5 cylinder engine, fuel type doesn't matter, spark ignition.

Would you rather have a small displacement long stroke engine, or a large displacement short stroke engine?

[pgfpro]

Originally Posted by Christ

No, I was asking for your personal opinion on which one you'd rather have -

5 cylinder engine, fuel type doesn't matter, spark ignition.

Would you rather have a small displacement long stroke engine, or a large displacement short stroke engine?

Oh LOL

So I can't have one square?

I would go with the small displacement long stroke engine.

[pgfpro]

OK after reading through this long messed up thread I'm very confused.

What are the questions???

LMAO

I need some cliff notes

[Christ]

There were questions in here? I thought it was just to say that MythBusters sucks?