Cylinder crosshatch general purpose vs. race

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statsystems
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Re: Cylinder crosshatch general purpose vs. race

Post by statsystems »

createaaron wrote:
David Redszus wrote:It seems that the brush hone does not remove metal peaks to create a plateau finish. Instead, it merely cleans debris from the grooves, which is useful but not its intended purpose.

Does anyone have a brush hone, polished mirror finish metal surface and a profilometer?
It would be a simple matter to prove or disprove the function of a brush hone.
I will get profilometer readings for you David. I just honed a LS block at school, 70 grit, 120 grit, and fixed plateau brushes in our sunnen. BTW, this is the way our teacher teaches us. Not trying to imply its correct, just putting the info out there. anyway, check back with values later..

120 and a brush? I never did any less than 220 and mostly 280 and a brush.

I wish I'd have kept all my info.
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Re: Cylinder crosshatch general purpose vs. race

Post by 4vpc »

David Redszus wrote:It seems that the brush hone does not remove metal peaks to create a plateau finish. Instead, it merely cleans debris from the grooves, which is useful but not its intended purpose.

Does anyone have a brush hone, polished mirror finish metal surface and a profilometer?
It would be a simple matter to prove or disprove the function of a brush hone.
If brush is same as ball i'm finding that hard to believe. For it to clean a groove would it not have to follow it exactly? What is your source for that statement?

Don't laugh too much, but I have a theory about honing and it is that it provides a surface which is designed to be worn away if and when needed. Lets say you hone whilst stressing the block the best you can, as per previous posts there will still be some other minor distortion you can't replicate when it's up and running. The piston rings can then wear the bore to suit this new shape and this means the coarsness of finish is dependent on how close you are to final shape.
There is no S on the end of RPM.
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Re: Cylinder crosshatch general purpose vs. race

Post by 4sfed »

David Redszus wrote:It seems that the brush hone does not remove metal peaks to create a plateau finish. Instead, it merely cleans debris from the grooves, which is useful but not its intended purpose.

Does anyone have a brush hone, polished mirror finish metal surface and a profilometer?
It would be a simple matter to prove or disprove the function of a brush hone.
I don't think Brush Research claims its products produce a plateaued surface, but are intended to clean debris and smeared material left from rigid honing. There's a study on their website, that can be downloaded, with SEM (scanning electron microscope) photos showing before and after surfaces at 100X and 1000X . . . http://info.brushresearch.com/study-of- ... -structure. You'll need to enter your information before you can download the study.
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Re: Cylinder crosshatch general purpose vs. race

Post by David Redszus »

If brush is same as ball i'm finding that hard to believe. For it to clean a groove would it not have to follow it exactly? What is your source for that statement?
The term "brush hone" has caused some confusion. There are several devices that could qualify as "brush hones".

The first is an abrasive filament protruding from a twisted wire; used primarily for small holes. The pressure that it can apply to the honed surface is a function of filament stiffness and length, and brush diameter. As the filaments wear and get shorter, the surface pressure is diminished, changing the surface roughness profile produced.

The second is a collection of abrasive filaments attached to an expanding rigid stone. The honing pressure can be adjusted for wear by expanding the honing mandrel. And the same honing machine and set-up can be used.

The third is made by Brush Research and is usually called a "ball" hone. It is conformable to the honing surface and cannot be used to correct bore geometry. If sized correctly (approx 10% larger than the bore), it can provide an excellent surface profile. Consisting of a ball shaped abrasive provides higher local contact pressure but is affected by wear.
Don't laugh too much, but I have a theory about honing and it is that it provides a surface which is designed to be worn away if and when needed.
That theory is exactly the opposite of modern honing technology. Properly sized and honed cylinder bores should be able to seal immediately and prevent (or at least limit) wear of both rings and bore finish. The ring should never touch the cylinder wall; it should ride on a film of oil. There are several areas of an engine that require break-in, rings are not among them.
Lets say you hone whilst stressing the block the best you can, as per previous posts there will still be some other minor distortion you can't replicate when it's up and running.
Cylinder bore distortion has been carefully studied for at least 40 years. Technical papers have been written by piston and ring and honing equipment manufacturers. The causes of bore distortion are known as are the corrective measures. But unless the engine builder can accurately measure the surface profiles and geometry, old practices will prevail.
The piston rings can then wear the bore to suit this new shape and this means the coarsness of finish is dependent on how close you are to final shape.
Not good. If a ring were to wear the bore surface to comply with a distorted bore shape, the ring would be worn or damaged, the bore surface would lose its crosshatch oil retention valleys and engine life shortened considerably. A very smooth surface does not contain oil and heat builds up very rapidly. Hot rings expand to butt ends, lack of oil causes micro welding in the ring grooves, blowby and oil consumption are increased. A rough or coarse surface is not cleanly trimmed by the action of rings. In fact, rings will most often simply fold the surface peaks into the valleys, defeating the purpose of a plateaued surface.
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Re: Cylinder crosshatch general purpose vs. race

Post by 4vpc »

Thanks for the excellent answers David, as i'm on my phone i'm being brief and hoping to not appear argumentative as I'm learning lots here . The rings do contact the bores sometimes as they wear them away, I wonder when this is, cold start up or full load etc.
There is no S on the end of RPM.
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Re: Cylinder crosshatch general purpose vs. race

Post by zums »

Does anyone have a brush hone, polished mirror finish metal surface and a profilometer?
It would be a simple matter to prove or disprove the function of a brush hone.[/quote]


If I get time I could provide that info ,have a typical late sixties early seventies 350 block with miles on it already have the recorded original finished data and Mirror finished data if I get time I'll Flex it measure it and then brush it and measure it
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Re: Cylinder crosshatch general purpose vs. race

Post by createaaron »

statsystems wrote:
createaaron wrote:
David Redszus wrote:It seems that the brush hone does not remove metal peaks to create a plateau finish. Instead, it merely cleans debris from the grooves, which is useful but not its intended purpose.

Does anyone have a brush hone, polished mirror finish metal surface and a profilometer?
It would be a simple matter to prove or disprove the function of a brush hone.
I will get profilometer readings for you David. I just honed a LS block at school, 70 grit, 120 grit, and fixed plateau brushes in our sunnen. BTW, this is the way our teacher teaches us. Not trying to imply its correct, just putting the info out there. anyway, check back with values later..

120 and a brush? I never did any less than 220 and mostly 280 and a brush.

I wish I'd have kept all my info.
Sorry, I meant 220.
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Re: Cylinder crosshatch general purpose vs. race

Post by Kenny M »

Here are some numbers..
Sunnen CK10 OEM 428 CJ Block
518 Stone 45 pressure set on #3 618 Stone 40 pressure set on #2 Sunnen Brushes 30 Pressure set on #2 Seven Strokes



RK 130 85 48

RPK 45 35 15

RVK 70 60 45


Mascar Classics
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Re: Cylinder crosshatch general purpose vs. race

Post by wyrmrider »

I plateau honed
then usually blocks got test assembled and sat around awhile
so I used a fine Brush Research tool to freshen
I did not realize that one purpose of the ball hone is to clean
IDK if they re-plateau
they do work for final freshen
cheers
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Re: Cylinder crosshatch general purpose vs. race

Post by David Redszus »

After a bit of research (reading), I uncovered the fact that a surface profile given by Ra is not an
actual measurement, but is the average of peak and valley heights from a calculated mean line.

For a given measured surface with a Ra value of 40, the Rt value (highest peak to lowest valley) should be 348 m", or about 8.7 times the Ra value. If the measured Rt value is more than 10 times the Ra value, you either have a honing problem or have a plateaued surface, of some kind.

The Rpm (average peak height above the mean line) would be then be 116.

If a second honing operation is applied to a honed surface, the Ra value cannot be used to determine the surface profile. A more complex, statistical calculation must be used, called Abbotts Bearing Curve.

Being a curious cat, I recently purchased a surface profilometer for experimentation using various abrasives and metal surfaces in an attempt to better understand the plateau honing process and its benefits to improved performance.
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Re: Cylinder crosshatch general purpose vs. race

Post by modok »

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Re: Cylinder crosshatch general purpose vs. race

Post by createaaron »

David Redszus wrote:After a bit of research (reading), I uncovered the fact that a surface profile given by Ra is not an
actual measurement, but is the average of peak and valley heights from a calculated mean line.

For a given measured surface with a Ra value of 40, the Rt value (highest peak to lowest valley) should be 348 m", or about 8.7 times the Ra value. If the measured Rt value is more than 10 times the Ra value, you either have a honing problem or have a plateaued surface, of some kind.

The Rpm (average peak height above the mean line) would be then be 116.

If a second honing operation is applied to a honed surface, the Ra value cannot be used to determine the surface profile. A more complex, statistical calculation must be used, called Abbotts Bearing Curve.

Being a curious cat, I recently purchased a surface profilometer for experimentation using various abrasives and metal surfaces in an attempt to better understand the plateau honing process and its benefits to improved performance.
Keep this post alive with your findings. If you play around with brushes, flex hone, etc...
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Re: Cylinder crosshatch general purpose vs. race

Post by David Redszus »

createaaron wrote:
David Redszus wrote:After a bit of research (reading), I uncovered the fact that a surface profile given by Ra is not an
actual measurement, but is the average of peak and valley heights from a calculated mean line.

For a given measured surface with a Ra value of 40, the Rt value (highest peak to lowest valley) should be 348 m", or about 8.7 times the Ra value. If the measured Rt value is more than 10 times the Ra value, you either have a honing problem or have a plateaued surface, of some kind.

The Rpm (average peak height above the mean line) would be then be 116.

If a second honing operation is applied to a honed surface, the Ra value cannot be used to determine the surface profile. A more complex, statistical calculation must be used, called Abbotts Bearing Curve.

Being a curious cat, I recently purchased a surface profilometer for experimentation using various abrasives and metal surfaces in an attempt to better understand the plateau honing process and its benefits to improved performance.
Keep this post alive with your findings. If you play around with brushes, flex hone, etc...
So far it seems that the type of honing abrasive is far less important than the technique being used.
Surface speed, honing angle, type of lubricant, will all produce a different surface finish, even using the same stone.

What remains as an unresolved mystery is the determination of what surface finish is actually produced compared to the finish best suited to the application.
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Re: Cylinder crosshatch general purpose vs. race

Post by modok »

Scientific method. The more data you have the better, but that sure is difficult to guess any given block how it will hone.
I did a 350 chevy today that was SO SOFT. I was removing material 2-3x faster than usual. Doesn't look any different than any other 350..... Why? Who knows.
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Re: Cylinder crosshatch general purpose vs. race

Post by jed »

I think u were using more pressure and weren't paying attention??
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