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Saffil is the company that made the FRM technology possible in our blocks, Honda aparently contracted them to create the sleeves for the B21/H23/H22/F20C/F22C/C30A/C32A engines. I hope this info well help a lot of you guys out, I just found it about 5 minutes ago and I didn't even get to read it all... It's all in the PDF file.
http://www.saffil.com/metal.htm
http://www.saffil.com/pdfs/automotive/data/mmcprop.pdf

For those who cant open PDF's:

PROPERTIES OF METAL MATRIX COMPOSITES
Saffil has been actively involved in the development
of metal matrix composite (MMC)applications since
1980,producing grades of Saffil fibre tailored to meet
the stringent echnical requirements of reinforced
aluminum components such as pistons and engine
blocks.
The driving force behind new engine work is the need
to build lightweight units capable of delivering higher
performance,improved fuel economy,lower
emissions and reduced noise levels.
For more than a decade,Kolben Schmidt,Mahle,AE
and Toyota have pioneered the use of Saffil fibre
reinforced pistons for diesel engines,while Honda
Motor Company focused on the reinforcement of
engine blocks.
In 1990,Honda launched a new generation of
aluminum engine blocks with fibre reinforced cylinder
walls replacing traditional cast iron liners.The first
model selected for production was the Prelude Si,a
16 valve in-line 4-cylinder engine,using a new
casting process to incorporate the Saffil -carbon fibre
hybrid preforms.

Elimination of he cast iron liner using MMC
technology allows a reduction in material thickness
between the adjacent bores.Tightening the cylinder
spacing in this way results in reduction in he overall
length of the engine and a weight saving on the block
of around 4.5kg.
Honda has since expanded the use of MMC engine
blocks and include models of he Accord,Ascot
Innova and the S2000.
Honda has also developed a high pressure die
casting (HPDC)process for manufacturing the MMC
engine blocks which reduces process costs and
enables widely available equipment to be employed
(See tables 8 and 9)
KS Aluminum-Technologie AG is also using Saffil
fibres with silicon particles (LOKASIL)in engine
blocks and at 17%loading o reinforce the cylinder
head in a turbo charged,4-valve diesel engine.The
cylinder head is produced by squeeze casting.
Figs.1 to 6 and tables 2 to 4 show data for
composites based on typical piston alloys.In all
cases,the Saffil fibre was incorporated in an
approximately random planar orientation.
At 300 o C,the presence of the fibre has improved the
ultimate tensile strength (fig.1)by a factor of 4.I
also extends the maximum use limit of the alloy to
around 500 o C,a peak temperature which is
sometimes approached in he combustion bowl rim of
diesel engine pistons.
Useful improvements in high temperature fatigue
strength are demonstrated by the data in table 2 and
fig.2.The scatter displayed by the pure alloy is
almost eliminated by adding the fibre.The modulus
has been increased to values in excess of those
predicted by theory for a random planar array of
fibres.This indicates strong fibre -matrix bonding and
also the effect of modified matrix microstructure.At
300 o C,the composites containing 18%and 24%fibre
have a higher modulus than the unreinforced alloy at
25 o C (fig.3).
The coefficients of thermal expansion are lower than
in the pure alloy (table 2)and the difference
increases with the volume fraction of fibre.
The thermal conductivity is lower than for the
unreinforced metal and decreases as the fibre level
rises (fig.4).It is higher in the direction parallel to
fibre orientation planes than in the normal direction,
but in all cases,is much higher than for Niresist iron
which is frequently used for piston inserts.
The wear resistance of the alloy is greatly improved
by including only a small volume fraction of fibre.Fig
5 shows data for 4.4%v/v addition of RG grade Saffil
fibre.Wear of the mating component,in this case Cr-
steel,might be increased by contact with the
reinforced alloy,but can be avoided by using RG
grade fibre with the appropriate alpha alumina level.
Additional wear data giving results for a higher fibre
loading and also a comparison with Niresist are
shown in Fig.6.
The hardness at 25 o C increases linearly with
increasing volume fraction of fibre to a value over
60%greater han the unreinforced alloy for a volume
fraction of 0.24 (table 4).As expected the composites
also display much greater hardness than the pure
alloy at elevated temperatures (table 2).

Other Alloys
All he preceding composites data refer to alloys
commonly used in pistons.Composites based on
other alloys show enhanced ultimate tensile strength
even at room temperature.For example,(fig 7).Such
composites usually show higher strain o failure than
those based on piston alloys (table 5).The presence
of he fibre in aluminum alloys generally results in
modified microstructure.(fig 8)and in particular,in a
reduced grain size.
 

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i must have missed that dano, this was all I saw on cost saving, and it sounds like a more current happening:
"Honda has also developed a high pressure die
casting (HPDC) process for manufacturing the MMC
engine blocks which reduces process costs and
enables widely available equipment to be employed
(See tables 8 and 9)"

this is what stands out to me: " results in reduction in the overall length of the engine and a weight saving on the block of around 4.5kg. "
sounds like they were trying to make a better block
 

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Tecknixia said:
If this metal is so strong... how much boost do you think it's capable of handling?

Oh wait... I guess it'd be more of a piston issue huh...?

So I guess there's no aftermarket pistons with same size as stock pistons?

Hmmm...
boost isnt a factor when determining strength...boost doesnt break stuff...horsepower does
 

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crzy
cool find carboy
...speakin of finding...WHERE did you find that?

that stuff is pretty strong...even after my rod snapped in half and blew a hole in the block (it was below the cylinder wall...in the skirt thing of the block)
the cylinder wall was not scatched up or anything...still could see the cross hatch after 200k miles :|
 

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tsiah said:
crzy
cool find carboy
...speakin of finding...WHERE did you find that?

that stuff is pretty strong...even after my rod snapped in half and blew a hole in the block (it was below the cylinder wall...in the skirt thing of the block)
the cylinder wall was not scatched up or anything...still could see the cross hatch after 200k miles :|
the durability of the sleeves is what creates the high friction levels with the rings. The rings get chewed up, not the sleeves...
 

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Discussion Starter #11
I forgot how I found it really...I was searching for something, then I got sidetracked, then I get sidetracked another 2000 times, and I find myself searching for " honda aluminum oxide fiber" and then I come across this company's website, and I find out the name used more regularly with these professionals is not FRM, but rather MMC, so I just search google for "honda metal matrix composite" and I look through 25+ pages of google results....and viola - some info...
If you guys wanna try to find more info on this MMC, use that to search instead of "FRM" you should be able to find some stuff too....
I found two sites that were oftering indepth scientific testing on MMC and it's strength, wear resistance, and heat dissipation vs conventional cylinder sleeve materials but in order for me to access those tests I had to be a special member of this scientific community and it costs money too...so, there is info out there, it's just a matter of finding it.

Cowsnuker, that is a picture of what the b21a1 blocks all look like...
 

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mouchyn said:
the durability of the sleeves is what creates the high friction levels with the rings. The rings get chewed up, not the sleeves...
Wrong. Replace the rings and you will still burn oil. It is the FRM that is the problem. Anyone who has looked at the scoring present in a B21 block can attest to this.
 

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chrisb said:
mouchyn said:
the durability of the sleeves is what creates the high friction levels with the rings. The rings get chewed up, not the sleeves...
Wrong. Replace the rings and you will still burn oil. It is the FRM that is the problem. Anyone who has looked at the scoring present in a B21 block can attest to this.
but like I said...my cyl walls were not scored when i tore the engine down
 

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My sleeves also looked nice, but the whole friction/oil thing sucked.
My car got to the point when it demanded oil on a daily basis, and snapped the connecting rod. I'll find a picture of it later. lol
 

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cowsnuker said:
My sleeves also looked nice, but the whole friction/oil thing sucked.
My car got to the point when it demanded oil on a daily basis, and snapped the connecting rod. I'll find a picture of it later. lol
ditto. beautiful sleeves. beautiful oil passages in the head. Required almost a quart of oil per day. spun a bearing. pulled the block apart. rings were worn very unevenly.
 

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yep and it's all due to the sleeves not being properly honed from the factory. they used the wrong method and it ended in disaster. but look at it this way. it only took them a year and a half to figure out what went wrong and to fix it. all blocks made after june of 91 were fine. it's in a honda tsb if you don't believe me just go to your dealership and look it up.
 

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kevinp4685 said:
yep and it's all due to the sleeves not being properly honed from the factory. they used the wrong method and it ended in disaster. but look at it this way. it only took them a year and a half to figure out what went wrong and to fix it. all blocks made after june of 91 were fine. it's in a honda tsb if you don't believe me just go to your dealership and look it up.
Actually it took longer then that. There are a few h23 floating with the same problem.
 

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I understand why B21's eat oil but someone explain to me why we snap so many rods in them when we maintain oil level? We all talk about how our engines ate oil and then busted rods. I assume you where like me and checked it about daily and assuming we always topped off, we never starved the engine of oil.

I know the rods breaking is typically a by-product of worn bearings. What causes this? lack of oil? But then I just made a point of keeping the level high and they still seem to blow (blew on mine with decent oil level...). You think it was a result of a prolonged period of oil level issues (like it was low before we realized it ate oil...or the former owner didn't realize it?)?

And I have to agree that it's the rings that fail causing the engine to burn oil. The FRM/MMC sleeves don't mix with the stock rings and it's the rings that loose the battle (regardless of the reasoning)...

How many have seen the inside of a B21? I just saw the inside of one for the first time this weekend (never took the head off of mine). It's a very light grey color (the sleeves).
 
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