Ceramic Coating

[Mark(The Miser)UK]

This experiment could be likened to a giant engine precup.

http://www.monolithic.com/plan-design/ceramic/index.html
Click on the graph and enlarge by holding 'ctrl' on keyboard and rolling mouse wheel :idea:

[tylernt]

Check out this very long but very interesting article:

http://www.patentstorm.us/patents/5915351-description.html

Maybe the reason a ceramic-coated prechamber had poor results because the timing was not retarded to compensate.

See, I always thought an insulated prechamber would be nothing but good. The poor real-world results may be the result of an unintended variable!

[SootME]

This has been a great post.  Very informative and compelling.  However I would hesitate in making the leap w/ the analogy below...

This experiment could be likened to a giant engine precup.

http://www.monolithic.com/plan-design/ceramic/index.html
Click on the graph and enlarge by holding 'ctrl' on keyboard and rolling mouse wheel :idea:

The heat in the article is radiated primarily through the infrared of the electromagnetic spectrum, which sunlight pretty much encompasses, where-as heat gain in a combustion chamber is most likely due from convection and conduction.  Thus physical characteristics that have an effect upon wavelength, ie. color are most successful in reflecting heat via radiation and other physical characteristics, though not negligible, are lesser.

[Mark(The Miser)UK]

This has been a great post.  Very informative and compelling.  However I would hesitate in making the leap w/ the analogy below...

This experiment could be likened to a giant engine precup.

http://www.monolithic.com/plan-design/ceramic/index.html
Click on the graph and enlarge by holding 'ctrl' on keyboard and rolling mouse wheel :idea:

The heat in the article is radiated primarily through the infrared of the electromagnetic spectrum, which sunlight pretty much encompasses, where-as heat gain in a combustion chamber is most likely due from convection and conduction.  Thus physical characteristics that have an effect upon wavelength, ie. color are most successful in reflecting heat via radiation and other physical characteristics, though not negligible, are lesser.

Sootme'
You could well be right...but then again... the fuel burning in the chamber does produce light. But is it blue like a gasser or yellow like a school bunsen burner with air turned down. Maybe its blue with yellow spots!
Yellow being more like the sun. So does the heat transfer in a diesel mimic the sun more than a gasser? Very interesting point maybe. My mini quartz spark plug for tuning gassers show all the colour changes in a poorly tuned engine.
 :idea: Could it be that an engine running rich gets hotter not just because of the extra fuel but because of the increased visible radiation. Could that be why even a diesel can be given extra fuel and then extra air to produce extra power without overheating by keeping the  visible radiation down. :idea:

I have a diesel book from some 50 years ago that had a series of high speed photography shots through a quartz view lens that shows the burn sequence. It also shows detonation in a gasser too. Unfortunately picture quality is too lousy to reproduce.

[SootME]

I have a diesel book from some 50 years ago that had a series of high speed photography shots through a quartz view lens that shows the burn sequence. It also shows detonation in a gasser too. Unfortunately picture quality is too lousy to reproduce.

Interesting.. is this the same spectroscopy in the book as used to determine the presence of elements in measuring corrosion of spark plugs?  http://www.ornl.gov/sci/de_materials/documents/ASMEFall04Paper.pdf
No doubt there is heat gain through radiation, for all hot bodies radiate hence the spectroscopy you mention.  But I am inclined to say the majority of heat gain is due to convection and conduction due to the proximity of the combustion (unlike the 149,600 km distance to the sun).  I stand to be corrected when I said "the heat in the article is radiated primarily..." because our atmosphere does indeed absorb a great deal of the sun's energy and is transferred further through convection, hence the winds and currents.  Though within that article the more direct source of heat gain is that through radiation.

[Mark(The Miser)UK]

Well either we're in different solar sytems  or you should change your name to Soot IN YuR EyE...LOL :mrgreen:
 http://en.wikipedia.org/wiki/Astronomical_unit
The millions of miles does make it a rather large swirl chamber!


The book is a thermodynamics book
"Thermodynamics as applied to Heat Engines"

[jimfoo]

Visible light doesn't carry much heat. Heat is in the infrared spectrum, so if it would last, I imagine a ceramic with a coating of gold would be the best way to keep heat in. Question is how quickly would it turn black with soot?

[jtanguay]

Visible light doesn't carry much heat. Heat is in the infrared spectrum, so if it would last, I imagine a ceramic with a coating of gold would be the best way to keep heat in. Question is how quickly would it turn black with soot?

visible light can actually carry quite a bit of heat... the gold would turn black pretty quick though...

[SootME]

My bad on the distance... Yeah it would be a massive swirl chamber.  Light being energy, all energy equates to heat, even visible, lasers and ultraviolet burn.

[jimfoo]

But infrared carries more heat than the shorter wavelengths.

[subsonic]

So would coating the injector heat shields help at all?  Would they flex when tightened and wreck the coating?

[Mark(The Miser)UK]

So would coating the injector heat shields help at all?  Would they flex when tightened and wreck the coating?

Put them in wet? :idea:

[SootME]

I apologize I don't know if I derail the post more then help but... what if inefficiency in ceramic coating certain areas, ie. the swirl chamber or precups, was not dependent upon thermodynamics but rather aerodynamics.  Are the swirl chamber's walls deliberately roughed up to promote turbulence and just the right amount of swirling?  Would applying a surface such as ceramic coating actually smooth the wall too much?  Likewise turbulent boundaries have a direct effect in heat transfer through convection (see link). wall?http://physics.ust.hk/penger/PRL_v81_987.pdf

[tylernt]

I apologize I don't know if I derail the post more then help but... what if inefficiency in ceramic coating certain areas, ie. the swirl chamber or precups, was not dependent upon thermodynamics but rather aerodynamics.  Are the swirl chamber's walls deliberately roughed up to promote turbulence and just the right amount of swirling?  Would applying a surface such as ceramic coating actually smooth the wall too much?  Likewise turbulent boundaries have a direct effect in heat transfer through convection

Ah yes that is a very good point. Swirl and turbulence is critical or the fuel will not be dispersed among the oxygen properly. That's why you should never polish the intake ports on a gasser cylinder head to a mirror finish. Maybe in order to do a thermal coated prechamber we need to keep the surface rough and retard the timing... maybe change other variables. Hopefully the coating is very thin also, or it may change the geometry of the "throat" and affect the swirl pattern.

I think it'll work we just need to refine the details.

[Mark(The Miser)UK]

I apologize I don't know if I derail the post more then help but... what if inefficiency in ceramic coating certain areas, ie. the swirl chamber or precups, was not dependent upon thermodynamics but rather aerodynamics.  Are the swirl chamber's walls deliberately roughed up to promote turbulence and just the right amount of swirling?  Would applying a surface such as ceramic coating actually smooth the wall too much?  Likewise turbulent boundaries have a direct effect in heat transfer through convection (see link). wall?http://physics.ust.hk/penger/PRL_v81_987.pdf

No derailing by your posting; just useful input.  :wink:

Doesn't the tangential entrance do a lot of the mixing work.Maybe the roughness helps.
Could just be cost cutting... else exhaust manifold would be polished. :?: