Cylinder crosshatch general purpose vs. race

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modok
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Re: Cylinder crosshatch general purpose vs. race

Post by modok » Mon May 01, 2017 8:24 am

Probably not, I've honed over 500 engines with this machine, we got a pretty close relationship at this point.
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Re: Cylinder crosshatch general purpose vs. race

Post by racear2865 » Mon May 01, 2017 9:14 am

modok wrote:Probably not, I've honed over 500 engines with this machine, we got a pretty close relationship at this point.
Just 500. No way youve learned that quick. HeHe.. Hell I have people come in the shop that stayed at the Holiday Inn last night that knows more than me. Did machine work on a V6 a few months back. Guy kept complaining for using oil. I told to remove engine and bring it here and we would disassemble and if problem I would pay for all rework. Got it down, asked what kind of oil did they start it on. Mobil 1 synthetic. All rings were lined up. He said that was what the instructions said to do. On fire up let it idle for 30 minutes and it sort of got hot. I asked what hot meant he said pegged needle. Had air block and thermostat stuck. Used the old one. But they did nothing wrong!!!!
reed

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Re: Cylinder crosshatch general purpose vs. race

Post by MotionMachine » Mon May 01, 2017 9:44 am

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.

There are many shops (even a self-described guru on Youtube) that use an older profilometer measuring Ra only. You need 5 measurements that these models do not provide. I've used mine so much that I actually wore out my stylus just last week. It actually fractured somehow and the tip is gone. Fortunately it was a sudden failure so it was obvious there was something wrong when I used it on a particular block that I've done many times before and therefore had a record of what method works on it. I normally get a valley of around 40 but I was getting 10, a number I've never seen before. The standard that came with my SJ210 is 117, it now reads 56. It always checked within 1 of 117 before so I looked at it under magnification and no stylus. Fortunately Mitutoyo does a quick turnaround on stylus replacement!

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Re: Cylinder crosshatch general purpose vs. race

Post by RW TECH » Fri May 05, 2017 4:29 pm

I did a ball hone (aka flex hone, bead hone, dingleberry, etc.) test on a very well worn Brodix block with 4.165" bore Darton sleeves.

- Same cylinder measured before & after
- Measured with Mitutoyo SJ-210 with brand-new probe
- Honed with a 4"-4.25" silicon carbide 400-grit BRM flex hone
- Go-Jo hand cleaner (lots & lots) used for honing lube

BEFORE - WORN CYLINDER
Rk - 8.22
Rpk - 2.21
Rvk - 13.06

AFTER 50 STROKES WITH 400 GRIT SC FLEX HONE IN A CRAFTSMAN 1/2" HAND DRILL
Rk - 23.59
Rpk - 11.31
Rvk - 31.32

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Re: Cylinder crosshatch general purpose vs. race

Post by MotionMachine » Fri May 05, 2017 5:04 pm

RW TECH wrote:I did a ball hone (aka flex hone, bead hone, dingleberry, etc.) test on a very well worn Brodix block with 4.165" bore Darton sleeves.

- Same cylinder measured before & after
- Measured with Mitutoyo SJ-210 with brand-new probe
- Honed with a 4"-4.25" silicon carbide 400-grit BRM flex hone
- Go-Jo hand cleaner (lots & lots) used for honing lube

BEFORE - WORN CYLINDER
Rk - 8.22
Rpk - 2.21
Rvk - 13.06

AFTER 50 STROKES WITH 400 GRIT SC FLEX HONE IN A CRAFTSMAN 1/2" HAND DRILL
Rk - 23.59
Rpk - 11.31
Rvk - 31.32

I've found the exact same thing, the numbers come right back with the 400 grit ball hone. I was never a believer until I did my own test. I use this a lot on one type of engine I do and it saves having to put the plates on and put it back in the hone and remove material to get the numbers back.

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Re: Cylinder crosshatch general purpose vs. race

Post by David Redszus » Thu Jun 15, 2017 1:11 pm

- Measured with Mitutoyo SJ-210 with brand-new probe
The SJ-210 has some outstanding capabilities that are really useful when attempting plateau honing.

Can you post the pc slice area ratios and the BAC graphic? I'm sure most folks have never seen what a honed surface actually looks like.

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Re: Cylinder crosshatch general purpose vs. race

Post by createaaron » Sun Jul 30, 2017 5:14 pm

So I find this post ironic now because I have since found a job in a race shop and we do not even own a profilometer. We build various circle track, dirt and asphalt engines as well as some drag and road race. Would be interesting to see the values of the bore, we get that thing SMOOTH!

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Re: Cylinder crosshatch general purpose vs. race

Post by modok » Sun Jul 30, 2017 7:39 pm

I did a old toyota for a buddy. He went with Hastings moly rings (I would have gone chrome NPR)
So I used 518 for base finish, then 6-7 strokes with 623, then 6-7 strokes 818, slightly less pressure and strokes than I would usually use.
Course, I didn't tell him it was an experiment. Friends and family...... best test subjects.

He pulled the header off after several thousand miles and we were amazed to find nothing but light grey and even white deposits. I didn't think anything could run that clean with modern pump gas.
Probably be a touch lean, but... sure not using a drop of oil, not in any detectable way, and the oil was clean too.
I'm just going to have to keep pushing till I find a limit :shock:

Did you put that one you honed together and run it yet???? Might work fine. Only one way to know.
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Re: Cylinder crosshatch general purpose vs. race

Post by midnightbluS10 » Sun Jul 30, 2017 7:48 pm

statsystems wrote:
David Redszus wrote:To obtain maximum performance from any engine, the piston rings must seal properly
to the cylinder bore surface, so as to contain combustion gas pressure. A proper ring
seal not only reduces power robbing exhaust gas pressure losses due to blowby, but
actually reduces ring drag friction and extends engine life while virtually eliminating the
ring seating break-in period.

Proper cylinder bore preparation allows optimal ring sealing which will help reduce ring
wear, oil consumption, excessive piston heat buildup and greatly reduce cylinder bore
wear. Pressure leakdown tests have shown that it is very possible to obtain ring sealing
values of less than 1% leakage in a cold engine and even less in a warm engine. An
engine with superb ring sealing will retain its sealing properties for a longer period of time.

This workbook will provide the information necessary to obtain proper bore preparation
procedures, and a quantitative rating system for accurate cylinder bore evaluation.

The essential ingredients of proper engine cylinder pressure sealing involve
certain primary areas:
Piston to Wall Clearance,
Cylinder Geometry,
Cylinder Material,
Surface Preparation.

Piston to wall clearance is essential to avoid destructive piston and ring damage due
to dimensional size changes. As the piston and bore material become warmer, both will
expand but at different rates due to material properties and differences in temperatures.
The rate of expansion of both piston and bore will be a critical factor during warm-up.
While cold clearances are typically specified, it is the minimum hot running clearance
that really matters.

Traditionally, piston to wall clearances are determined by trial and error, either by the
engine builder or piston manufacturer. This method has several drawbacks; the cost of
damaged pistons being one of them. Most often, the engine builder does not know the
co-efficient of expansion of the piston material or cylinder bore. The piston manufacturer
usually does not know the actual operating conditions of the engine nor the geometry
of the cylinder bore. The usual technique is to provide excessive clearance to avoid
destruction while accepting a loss of performance.

The Piston Clearance workbook can be used to accurately predict the required piston
to wall clearances for any piston or bore material, as well as ring materials. The proper
cold clearance dimension will be determined by piston and bore materials, operating
temperatures and mode of operation. The workbook can then predict hot running
clearances and transitional warm-up clearances for both pistons and rings.

Cylinder geometry refers to the determination of the bore distortion. Bore distortion
has several forms: out of round called ovality, lack of straightness called taper, cylinder
perpendicularity called tilt and cylinder macrowaviness called waviness.

Cylinder bore ovality (out of roundness) cannot be totally eliminated but can be reduced
using proper preparation techniques. When a cylinder head is bolted to a block the
bore size and shape will be distorted. So even if a bore is perfectly round before
assembly, it will deform when placed under bolt tension load when the head is attached.
A bore that starts out round may take on the shape of a four leaf clover depending on
the number of head bolts, their location and cylinder position.

In order to obtain a round cylinder bore after assembly, it is necessary to distort the bore
before assembly by means of a preloading while the cylinder bore is being honed to size.

To correctly pre-distort the block and bore, a pseudo head called a deck plate is used,
bolted to the block. It is essential that a compressible head gasket be used, that deck
plate bolt length penetrate into the block the same depth as actual head bolts and that
the plate bolts are torqued the same as an actual cylinder head would be torqued. In
addition, main bearing caps, motor mounts and transmission bell housings are often
attached as well to pre-distort the lower cylinder bore.

Some engine builders have advocated pre-heating the block in anticipation of operating
temperature expansion and distortion. For most engines, pre-heating has shown very
little benefit, compared to the bore distortion which results from combustion loading.

Depending on the cylinder bore size, the maximum permissible distortion due
to ovality should not exceed 0.01mm (.0004").

Piston rings that are radially flexible are capable of conforming to larger amounts of
piston bore distortion. Rigid (thick or wide) piston rings are much less able to flex
enough to adapt to the distorted bore shape. While a flexible piston ring might be able
to adapt to a simple shape distortion (such as an oval) it cannot adapt to a more
complex shape such as an apple, pear or clover leaf shape.

If a cylinder bore is out of round during loaded operation, the piston rings will not be
able to properly conform to the distorted shape, allowing combustion gas blowby that
will result in excess wear (indicated by bore surface polishing of cylinder cross
hatch areas), which will increase ring wear and cylinder bore wear.

Bore taper (straightness) is somewhat similar to ovality but in another direction; it is
the bore straightness in a vertical plane. A cylinder bore that is bell shaped, hour-glass
shaped, tapered or barrel shaped will cause the piston rings to slide excessively in a
radial direction. This will produce increased friction in the piston ring land often resulting
in stuck rings or excessive ring land wear.

The maximum deviation from straightness should not exceed 0.01mm (0.0004")
from the top to the bottom of the cylinder.

In order to determine ovality and bore straightness it is necessary to take several
diameter measurements of the cylinder bore at various angles and height locations.

Cylinder bore angle
In plan view (as viewed from the top) four measurements of diameter are necessary
in order to determine possible ovality. The usual measurement axis are at 0o or
along the crankshaft centerline, 45o from centerline, 90o from centerline and 135o
from centerline, although any similar angles may be used.

Cylinder bore height
In elevation view (as viewed from the side) four measurements of diameter are
necessary at various vertical positions in order to determine taper. Although any
vertical positions may be used for measurement some positions are more logical than
others. The most commonly used vertical positions are as follows:

Position A measures the diameter at the turnaround point of the piston
rings which is usually about 10mm from the block deck surface.
Position B is measured at the piston skirt edge height when the piston is
at its uppermost position. It is intended to measure possible cylinder
scuffing by the piston skirt caused by piston rocking at TDC crossover.
Position C is measured at the vertical position of the rings at the bottom
of the stroke.
Position D is measured at the very bottom of the cylinder, in an area
not scuffed by piston or rings. It is used to measure possible bore
distortion due to main bearing caps.

The measured diameters (16 in total) for each cylinder can be entered and recorded on
the Cylinder Geometry workbook data sheet. It will create a graphic for cylinder
ovality and straightness which may be saved as a reference for when the engine later
comes in for a rebuild.

Cylinder tilt (perpendicularity) refers to the angle of the cylinder centerline with respect
to the crankshaft axis. Ideally, the cylinder tilt axis should be at 90o to the crankshaft axis
in the longitudinal direction and intersect the crankshaft axis in the lateral direction. In
the real world, there will always be some deviation from the ideal value.

The amount of tilt angle that can be tolerated is highly dependent on bearing and piston
clearances. Consequently, the permissible tilt angle will usually be specified by the engine
manufacturer. If a new engine is being designed or modified, a good rule of thumb is to limit
cylinder tilt to a maximum of 5' deviation from perpendicular. Since 1 degree = 60' (minutes),
5 minutes deviation represents 5/60 or only .0833 degrees, which is a very small amount.

While most solid engine blocks are accurately machined by the manufacturer, the same
cannot be said when the crank bearing journals are align bored. Equally serious are
two stoke engines with separate cylinders which are clamped to crankcases and may often
exhibit a tilt deviation.

Cylinder waviness
Viewed in profile, refers to the deviation of the cylinder surface from a straight line. The
surface resembles a washboard effect superimposed on the surface roughness. The
maximum permissible waviness is often specified as one half of the surface roughness value.

Cylinder material
Cylinder bores may be constructed of various metals including aluminum, or cast iron.
In addition, the cylinders may be run naked (without coatings) or may have some type
of wear protective coating applied to the surface.

For most engines, cylinders of cast iron with lamellar graphite, are the most common
because of their cost and excellent running surface characteristics. For some applications,
cast iron bores may be chrome plated to provide a harder running surface.

Aluminum, because of its light weight, thermal conductivity and thermal expansion
characteristics which are similar to piston materials, is finding increased use in stock
based engines as well as racing engines. When aluminum bore material is used, it is
common to apply a wear resistant surface coating such as nickel with disbursed silicon
carbide particles (Nikasil).

New metallurgical techniques have produced high silicon aluminum alloys that can be
used without surface coatings.

Whichever cylinder or block material is used, it is imperative that the thermal expansion
properties of the material be known and taken into consideration

Perhaps the most important consideration regarding cylinder material is the hardness of
the metal or coating being used. The surface hardness will significantly affect the type
of surface that can be obtained and the honing techniques that must be used. The
harder the surface, the more difficult it becomes to obtain a proper surface texture,
particularly to obtain a deep scratch or honing groove.

The surface hardness will determine which type of honing stones must be used.
Diamond stones can be used for iron or aluminum for basic bore shape and size but
are not desirable to obtain a proper surface finish, even with harder surface materials.
Diamond abrasives, while they may last longer, tend to become dull and do not cut
with a sharp edge and will produce a shallow oil groove.

Ceramic abrasives such as silicon carbide or silicon boron will break off with use to
expose new and sharp abrasive edges. The drawback is their shorter useful life and
resultant higher operating cost.

A discussion of honing abrasive materials and the type of finishes which can be
produced with various grit stones can be found in the Abrasives workbook. Many
abrasive manufacturers publish data sheets that indicate the type of surface finish
that can be obtained on materials with various Brinell hardness values. These charts
must be taken with a grain of salt since honing oils, rotational and stroke speed, and
stone pressure, all effect the surface finish which is produced. When in doubt, hone
a test cylinder and send it to a metallurgical lab for measurement and evaluation.

Surface preparation
Perhaps the most significant advancement in the science of cylinder bore preparation
has been the development of measurement techniques of surface finishes. Accurate,
electronic measurement of running surfaces has permitted rapid microsurface evaluation
and cost effective production techniques.

Surface preparation consists of two parts, groove preparation and surface
roughness. Both parts are equally important and must be carefully
considered if optimum cylinder sealing is to be obtained.

Groove preparation evaluation is primarily visual and has several categories, each
with target values to be met and weighted features. The condition of the groove, its
shape and openness account for 40% of the total cylinder groove preparation rating
and must be considered very important.

Factors to be considered regarding groove preparation include the following:
Honing Angle
Groove orientation
Plateau formation
Groove condition
Macrowaviness

Surface roughness evaluation is primarily by measurement and also has several
categories, each with target values to be met and weighted features. The value of the
bearing surface area carries 45% of the total cylinder roughness rating and must be
considered equally important.

Factors to be considered regarding surface roughness include the following:
Groove width
Peak to valley height
Groove distance
Bearing surface area

Bearing surface area is sometimes called Abbotts Bearing Curve or simply Plateau Honing.
The first step is to bore to size and hone to shape.
A rough (120 to 180) hone is then used to obtain near net size and to provide a deep scratch
which intended to hold oil below the surface. A very smooth surface cannot hold oil.
A finish fine hone (400 to 600) is then used to remove the peaks of the cylinder surface, leaving
the deep scratches.
For a street engine, the top or plateaued surface target value is about 70%. For applications
subjected to heavier ring to wall loading, (race or turbocharged engines and diesels) a higher
percentage of plateau (80-85%) is necessary to provide adequate support for the rings.

Rigid stones, ball hones, and abrasive brushes all have their supporters. The tool being used is not as
important as the skill of the workman using the tool.

Remember that if you can't measure it, you don't know what you have.


Where do you buy a copy of the Piston Workbook?
Possibly through Precision Auto Research


http://www.precisionautoresearch.com/GE ... a/PAR7.htm

http://www.precisionautoresearch.com/ge ... e/PAR3.htm

I'm guessing it's in the Race Data Power stuff

http://www.precisionautoresearch.com/rdp/PAR37.htm

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Re: Cylinder crosshatch general purpose vs. race

Post by createaaron » Sun Oct 15, 2017 7:57 pm

modok wrote:
Sun Jul 30, 2017 7:39 pm

Did you put that one you honed together and run it yet???? Might work fine. Only one way to know.
It's in the midst of being raffled..

createaaron
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Re: Cylinder crosshatch general purpose vs. race

Post by createaaron » Sun Oct 15, 2017 8:10 pm

David Redszus wrote:.

The Piston Clearance workbook
Is the Race data power software available for purchase?

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