Russ Posted April 26, 2015 Posted April 26, 2015 Know of this method for yrs....query, does one just get cyls treated, pop in new rings, maybe pistons....and bobs your uncle ??
Guest GraemeM Posted April 26, 2015 Posted April 26, 2015 The way things are now days Bob is probably your aunty.
dazza 38 Posted April 26, 2015 Posted April 26, 2015 Apparently Chrome rings are no good for Nikasil bores. But don't quote me on that. Iron rings are OK though. 1
OZJohn Posted April 26, 2015 Posted April 26, 2015 I have been using Limbach motors with Nikasil cylinders for over 20 years ( not the same one ) and they do not wear. And yes the rings have to be special also. An ordinary hone will not touch them. Now the process is called electrosil and used extensively by motor bike racing folks. A company in Melbourne does them. Limbach also proved you need two carburetors and very well designed inlet manifolds for flat four engines for aircraft use. There's no place like cloud-base. John.
Pilot Pete Posted April 26, 2015 Posted April 26, 2015 I thought Nikasil was a coating used on alloy cylinders ? 1
OZJohn Posted April 26, 2015 Posted April 26, 2015 It is an electroplating process. Depending on what you want the wear resistance can be anywhere from 4 to 10 times better than cast iron or chrome bores. John.
Guest Andys@coffs Posted April 26, 2015 Posted April 26, 2015 Correct...There is an equiv for steel cylinders, though. I have heard of someone having it done in BNE but it didn't last long before is flaked off... (not sure if it was an application of the wrong plating to the wrong cylinder material, or its just dodgy) As suggested above there is a place in Melbourne that can do them I believed the process is called Eurosil but I cant now find the email trail from the L4 that I was discussing it with back then to confirm...Google doesn't seem to be my friend, but I'm not 100% sure of what I'm looking for, because Its not an area (firewall forward!) that I claim any detailed expertise over.
AVOCET Posted April 26, 2015 Posted April 26, 2015 I contacted the place in melb a couple of years ago inquiring about the process , i thought it was nicocil , They didn't want to do jabiru barrels , as they said the process wasnt suited to chrome / molly , they mentioned a couple of failed attemts . I dont have that contact , ( Lost data in a phone update ) Mike.
bexrbetter Posted April 26, 2015 Posted April 26, 2015 The intent of the process is to coat aluminium directly with a wafer thin coating to save weight and improve heat dissipation. I am aware of people who have removed their ferrous sleeves and coated the aluminium cylinder but they were looking for a capacity increase via a larger bore more than other reason. There is no practical reason to coat a ferrous cylinder. You must be more pedantic about your filtration with plated bores as they will score up but you can't just "hone it out" later. Obviously less an issue on a plane than a dirt bike. But typically my choice would be to find a suitable piston, and then bore out the ferrous sleeve to around 3mm thickness (leaves room for a couple more oversizes) or better still, I make up some big bore sleeves myself. I always use cast iron pipe stock by the way, retains oil better and transfers heat better than steels. I have made a heap of 'big bore kits' for myself and mates over my lifetime and it is truly as easy as it looks, turn your pipe to required size in a lathe, heat up your (pre-bored) cylinder and drop it in. Send it and your piston to an engine shop for final bore and hone. It ain't rocket science.
bexrbetter Posted April 26, 2015 Posted April 26, 2015 Know of this method for yrs....query, does one just get cyls treated, pop in new rings, maybe pistons....and bobs your uncle ?? If you are talking about an original plated cylinder that needs re-plating then the answer is yes. The old material is first stripped out before re-plating, it used to be frightfully expensive, about $400 per pot and a long wait sometimes because they were only done in batches and if you were early you had to wait until others arrived, but I haven't done it in many years and it's a bit more common so probably more viable now.
facthunter Posted April 26, 2015 Posted April 26, 2015 I have only heard of it being done on aluminium. I understood the coating is fused into the surface. The name means Nickel and Silicon. I have never believed it was plated in the normal sense, as with hard chrome. The normal way of hardening alloy steels in aircraft cylinders is by nitriding. This is NOT suitable for ball or roller bearings as you have to carburise the steel to about 1/2 mm depth and harden and temper it. This can cause distortion so normally requires grinding after hardening. Nev
bexrbetter Posted April 27, 2015 Posted April 27, 2015 The name means Nickel and Silicon. As I mentioned, Nikasil is just a brand name of just one company and they have their treatment process, there are a number of others with (patented) different content and processes but Nikasil carries the common term for them all as Bobcat does for skid steer loaders. Like Nikasil, the term "plating" is used, probably incorrectly, around the bike shops. Semantics.
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