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Letter 1671
Where is the Nikasil
supplier?
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I am searching for a supplier of "Nikasil" plating chemistry,
specifically interested in finding a solution operable in a "brush"
or selective plating environment.
The coating is being widely used in the manufacture of motorcycle
engine components (i.e, cylinder bores, pistons, piston rings) and
the restoration of engine cylinder bores.
Robin M

- Sears, MI
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Nikisil® is a proprietary product of Mahle. If you desire
information you should contact Mahle.
Dennis McCallister
Morristown TN
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Although Nikisil® is a trademark of Mahle Corporation, our
company has engaged in nickel silicon-carbide plating and diamond
honing in the United States since the mid 1960s. We are presently one
of the largest such companies in the world. We have found that by far
the greatest demand for nickel silicon-carbide has been for aluminum
cylinder bores, and the market still appears to be growing. We have
no method of "brush plating" this coating.
Scott Z. Reath
U.S.
Chrome Corporation of Wisconsin -
Fond du Lac, WI
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My company has been offering a Nickel/Silicon Carbide coating
service on aluminum cylinders for many years both here in Alabama and
at our original facility in England, and have a throughput of several
thousand cylinders each year. Like them too, we are not aware of any
brush plating technique that offers good results and a quick survey
of our associated companies around the world yields the same
response, but I suspect that one could be developed given sufficient
demand.
Geoff Slater
Auburn, AL
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My electroless nickel reference indicates that Elnisil is a
galvanically deposited dispersion coating of carbide, presumably
carbide in nickel. Brush plating of this process may be less
problematic than Kanisil or Nikasil, although the abrasion resistance
is less for Elnisil.
See Metzger, W. et al. galvanotechnik 61 (1970) 12, 998
 
Tom Pullizzi
finishing.com - Brick, NJ
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We need to put up a plant for Ni Sic plating for plating the bore
of our new engine. As the Volumes are not very big (around 30,000
engines per year) we are looking for a cost effective solution.
Can we modify an existing electroplating plant for Ni & Cr for
this process. Can I set up a pilot plant before mass production.
Would be grateful for replies
Kumar R

Jakarta Indonesia
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I would like to know whether any one has any experience in coating
Nikasil or similar composition on Graphite rods.
Venky C

- Illinois
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I am rebuilding a Porsche 911 engine which uses removable cast
iron cylinders. Can anyone recommend the most cost effective method
for plating the cylinders to restore them to their original
dimensions?
Ben M

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I am a student in Istanbul Technical University. I am interested
in Nikasil and Alusil. Which one of these gives better performance on
pistons (especially cars).I study Metallurgical and Materials
Engineering and this subject is my final work. Could you please send
me any documents about this subject or offer books, magazines etc...
Thank you.
Ozgur O

- Istanbul,TURKEY
Ed. note: letters 551,
2723, and
2858 address a similar
topic.
.
I have a few questions. Can nikisil® cylinders be honed once
or twice to clean them up? I've got a very low mileage 4-cycle engine
in which the pistons dry-seized to the cylinder wall during long,
improper storage. With steel sleeves I'd simply have a machinist
perform a very light hone to clean up the cylinders.
How critical is the matching of pistons, rings, and cylinders in
nikisil® set-ups? I've got a feeling it is a good thing, but
necessarily critical. The question developed because I've seen
suppliers selling piston, ring, and nikisil® cylinder sets. Two
rings on one of the aforementioned engine are stuck in the grooves
and must be replaced for engine reassembly. I would like to clean all
parts, hone the cylinders, replace all rings, and reassemble the
engine.
Thank you.
Bill S

- Concord, CA
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The first thing to be aware of is that the Nikasil layer will
probably be very thin, and so you should be prepared for that when
considering any machining operation.
Typically, engine manufacturers using Nikasil and similar
processes 20 years ago would have deposited a finish-machined
thickness of about 0.10 mm (0.004"). More recently, we have noted
that cylinders from several Japanese manufacturers have thinner
coatings, sometimes as thin as 0.05 mm (0.002"), almost certainly as
a result of improvements in the plating technology enabling a
reduction in materials and processing times.
In normal use, it should be unnecessary to hone nikasil-type
engine cylinders since the wear resistance and oil retention derives
almost as much from the presence of the silicon carbide particles in
the nickel matrix as from the original underlying honed surface
finish. In Bill S's situation, it appears that there are marks on the
bore which will need to be removed to avoid damaging new components
during a re-build, and so honing will almost certainly be required.
It is important that this be carried out using diamond honing tools
of an appropriate grade, since the original surface finish can easily
be "polished" by using conventional honing stones, and that may lead
to a lack of adequate lubrication during the initial running of the
engine.
One of the big performance advantages of nikasil-type bore over
traditional cast iron sleeves (other than a major weight saving) is
the ability to operate an engine with smaller piston to bore
clearances since the piston and the cylinder will tend to expand a
similar amount when heated. For that reason, it will be important for
Bill S to accurately measure the bores after honing, then select
pistons which will give him a clearance which satisfies the engine
manufacturers specifications. Most normal piston ring materials work
well with nikasil-type bores, but chrome faced rings (at least the
compression rings) are by far the most commonly supplied by engine
manufacturers. Close attention should be paid to the ring-end gap to
ensure compliance with manufacturers specs.
Sorry the reply is so long, but I hope it answers Bill S's and
some other questions at the same time.
Geoff Slater
Auburn, Alabama
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I would like to thank Mr. Geoff Slater of Auburn, AL for the rapid
and informative response to my engine rebuilding questions dated June
.. In his response, George apologized for making a long reply.
Apology accepted, however no apology was necessary. George provided a
great bit of information in a very concise manner. Not only did I
gain the confidence to rebuild the engine, but I was also provided
with useful practical and factual information. Believe me, there are
quite a few people claiming to be knowledgeable about engine coating
and plating that make it up as they go.
One last item, Geoff. The subject engine has been reassembled and
runs like a fine watch. The Italian motorcycle which this engine
powers is a 1986 Moto Morini 350K2. This model was one of the last
manufactured by Morini before they went out of business. The engine
is a V-twin having 70 degree cylinder offset and Heron heads (flat
head, combustion chambers in piston).
Thank you.
Bill S

- Concord, CA
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I am in the process of building some racing V-6 engines. These
engines have a metal matrix composite engine block with Reynolds 390
series alloy as the base metal. The bore is 93 mm.
Alternatively, has anyone ever done this to the pistons instead of
the block? My problem on this is that I have had to make forged
pistons due to the boost pressures involved with this project so the
aluminum on aluminum, won't cut it. I have exhausted all efforts to
find a company that can do an iron plating so I have had to go the
Nikasil route.
John C

- L.A. CA USA
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I've recently seized an engine on a 2000 YZ 125 dirt bike, and I
realize this might not be the place to ask, but I only had a few
quick questions :O). Since the 80's I believe the big four (Japanese)
companies have used a thin Nikasil coating which is supposed to
increase cylinder wear...etc...etc... I've been told that due to the
thin layer provided, rehoning the cylinder is impossible (Or at least
stupid) without having a new Nikasil coating added.
So my question is, if I only plan on having this bike for the next
few months, and I've just installed a new piston, rings, crankshaft,
and rod, will I be setting myself up for frequent engine failures and
bad performance?
If anyone has any information on the costs involved in the process
provided, I'd greatly appreciate it, Thanks.
Dean P

- Aurora, Colorado, USA
++
There seem to be alternatives to Nikasil for the wear resistance
improvement of aluminum cylinder bores. I've found companies that
specialize in the ceramic coating of engine components; even worn out
ones. Their claims seem to imply tremendous advantages. Check out
their sites and see what you think. There are also coatings for
"lubricity" using graphite and Molybdenum disulfide that are
deposited on cylinders and pistons to reduce friction & galling.
These are very high temperature coatings which ceramics seem ideally
suited to and various process for deposition seem to be well worked
out and not expensive. They have been used in racing vehicles for
many years. It's a real eye opener what ceramics can do for an
engine.
Good luck.
Peter K

Freelance - Kelowna, BC, Canada
October 23, 2008
Hello
I was looking for information on Nikasil and was pleased to find this
page with its useful information.
Although much is said of the benefits of coating cylinder bores with
Nikasil, there seems to be very little information available as to
what sort of piston ring is best for use with such Nikasil plated
bores.
I have been surprised to find that noone can give me a straight
answer! I have a 2-stroke engine with Nikasil coated aluminium
cylinders. Original piston rings are plain cast iron. My question is,
can one safely use chrome plated piston rings with Nikasil
bores?
My first thought was that the 2 together should increase longevity
however it's been suggested that the chrome rings will simply strip
the thin Nikasil layer from the bores and destroy the
cylinders.
Could someone who actually knows tell me the answer please?!
Many thanks,
Joe Conrad
engine rebuilding - Halifax, West Yorkshire, England
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November 18, 2008
Hi all,
Nikasil coating is now common on the bore of most Japanese
engines. They are inclined to run without liners (saving
weight) and the bore is coated with Nikasil which is a very
hard surface finish. Pistons normally run with chrome plated
rings (also a hard surface) and because of this there is a
requirement to run the two parts "hard" to bed in to each
other. Normal running in will not allow the parts to bed in
to each other and will cause piston blowby. This will allow
excess pressure into the crankcase causing oil to be pushed
out from the engine. If a Nikasil engine seizes usually the
piston melts onto the niksil surface and the bore can be
reclaimed by honing the deposited piston metal off the
bore.
Guys an gals hope this helps and greetings from Ireland (The
Capital Of the World) :)
Fast Fergie.
Fergus Finn
Research and development - Dublin, Republic of
Ireland
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December 17, 2008
I also have a 2-stroke motorycle motor with nikasil
coated cylinders.My problem is that my cylinder wall has a
light score in it(just enough to hook your finger nail)where
the piston/rings melted and broke apart.my questions
are:1.is the nikasil coating scored all the way through so
that it can't be repaired?2.can it be honed with a silicon
carbine hone in order to repair it myself or should i get it
bored and replated at a qualified company?3.what will happen
if i remove the nikasil coating and reinstall a new set of
piston and rings?4.what will occur if i leave the coating
scored and replace the pistons/rings?please take into
consideration that I am only young and have a limited amount
of income.Thanks in advance to everyone who respond to my
questions.
Steven Turnip
- Newfoundland,Canada
December 26, 2008
right to answer Steve Turnip
no dont hone it its too thin.if u remove the coating the
bore will be oversize and not seal and u will be running on
an aluminum base and it will last a very short time (seconds
probably). if u leave the bore scored then u will get blow
by, low compression, burnt piston/bore as the combustion
gases rush by. wont last long! sorry but re plate is the
only real answer.
now here is a question for u platers can anyone machine and
replate the epitroidal housing used in the norton rotary
engines. it seems that some engineering processes become
impossible.
John Hall
- Ripon, North Yorkshire, UK
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