Chamber textures

[BOOT]

While out working on a cylinder head chamber couple recent threads got me thinking. What if I were to burr finish most the chamber but polish about 1/2-1" perimeter around the exhaust valve?

I've only recent come over to the trend of burr finish working good in some chamber designs but I don't think it's one or the other but maybe both types of finish.


edit: Yes I know polished chambers are meant for heat reflection & detonation, but why not flow around the highly pressurized exhaust valve?

[modok]

Seems reasonable.
I don't think it would work worse, nothing to lose IMO
But I don't know if it would work better.

[David Redszus]

Combustion turbulence is violent in nature. The flame front does not go where you want it to go.
It goes where it wants and we don't know where that is.

The flame is quenched as it touches the chamber wall or piston dome.
That results in less fuel being burned and more carbon accumulation.

Given a choice without regard to heat losses to the surface a mirror finish would be ideal.
Until a carbon coating caught up with it.

[modok]

the trouble with "ideals" is they are only ideas. I think the reason that it has taken SO long to get this far, is putting too much faith in ideas and not enough on cut and try.
It may be, that if a combustion chamber had no walls, it would not be able to knock. But......how we test this???

[mag2555]

You need to look beyond what meets the eye in many chambers in terms of finish!

Many chambers such as this in the photo use a fast shape change lip above the plug on the Intake side as a few shear point to shred big wet balls or streams of fuel back into a more completely burnable state!

Breaking a sharp edge like this over by more then .010" as many people do only cuts back on power!