nikasil

Has anyone here done a build with nikasil on the Al barrels? I was thinking about it, you could used a big fin block with the stock size liner holes (or as cast) and take it to 80mm or more, without having to ream the cases as long as the skirts were short enough. Maybe the liners provide rigidity to the setup though.

Built with a liner for a reason.
$0.02

I've put 100k on a Moto Guzzi with the nikasil. Not only does the stuff last forever it doesn't retain the heat that liners will.

My Road Star cylinders are nickasil lined. Several of them out there over 150K miles with no top end problems.

I ordered a Nicom or nikasil line cylinder for my triumph. Heard many good things from reputable engine builders in my area.

From triplesrule.com where I picked up my big bore.

(NiCom® is U.S. Chrome Corporation's name for the nickel-silicon carbide coating often referred to as “Nikasil®”)

NiCom® is applied directly to aluminum bores through an electro-chemical plating process.

Triples Rule Triumph MotorcycleSince the NiCom® coating is thin (.003-.005”), heat transfer from piston to cylinder block is superior, drawing heat out of pistons more efficiently, making engine less prone to detonation (knocking or “pinging”) which can cause catastrophic damage. Heat transfer with this technology is more efficient even than an aluminum block with iron liners because although the liners typically have a ground surface finish and a tight press fit to the aluminum block, there is a barrier to heat transfer at that interface that is virtually non-existent with the NiCom® plated bores.

Another benefit is that the coefficient of expansion of the cylinder block is very close to that of the piston. This allows us to use tighter piston clearance than would be used with an iron block or an aluminum block with iron liners. The tighter clearance means better combustion chamber sealing, reducing blow-by and increasing power.

NiCom® has a composite hardness of 58 Rockwell-C and thus has far superior wear resistance when compared to cast iron. It is also repairable. In the event of damage to the bore the NiCom® can be stripped, re-plated and honed to the original spec. If the score or gouge is very deep the aluminum can be re-bored and then the NiCom® re-applied and an oversize piston fitted.

Can this be applied to steel liners, as in Mike's 750 kit?
I have also heard of a process where the cylinders are put in a solution and a vacuum applied. This draws the solution up between the sleeve and cylinder. This makes the sleeve to cylinder contact much tighter to better transfer heat.
Any one else hear of this?
Leo

My nephew just bought the 1811 cc Indian, and they used nikasil for those very heat control purposes, wanting no iron liners. It is said to work extremely well.

Nic is nothing new. It's been in the 2 stroke world for years. Most Hi Po 2 stroke snowmobiles have been using it since the mid 90's, and many of them before.

My Guzzis from the early 80's all had it. Went thru a California II with 68K on it and it was a waste of time, looked and speched brand new.

BMW's have used it since the early 80's in their bikes.

I don't think anyone was implying that it was anything new. The OP was inquiring as to our experience with the stuff. To that end, I have found that it works quite well. It is very tough and shows little wear as long as no scuffing occurs between rebuilds. You can hone it too, Sunnen has special stones for Nikasil, they are boron carbide. You can check with your local machine shop to see if they have them. If they rebuild European engines then the chances are good that they will.

In a pinch I have used a ball hone to deglaze the cylinders as long as they were in good shape to begin with and the clearances were within reason. Used new rings and they seated quickly with no complaints of oil consumption from the customer. Good luck with your project!

Color me stupid but;
There is no way you could drop the liners out, nikasil the inside of the barrels and run pistons in them.......

Technically you could. The nic tranfers heat better than the liners. What is the bore size of a new cylinder before sizing it for oem liners? You have to have piston size, figure your needed piston to wall clearance, add in the nic thickness to the available bore size then determine if it can be done. Are there pistons that come in that size range? One thing is ,are the jugs stable enough for use with out the steel liners? The liners go deep into the crank case, doubtful there is enough bore to piston skirt support on down stroke.

racerdave said:

Technically you could. The nic tranfers heat better than the liners. What is the bore size of a new cylinder before sizing it for oem liners? You have to have piston size, figure your needed piston to wall clearance, add in the nic thickness to the available bore size then determine if it can be done. Are there pistons that come in that size range? One thing is ,are the jugs stable enough for use with out the steel liners? The liners go deep into the crank case, doubtful there is enough bore to piston skirt support on down stroke.

Click to expand...

It would be highly irregular for a sleeved barrel to be stable enough to run without a sleeve. I'm sure the barrel was not engineered for the resonance and axial stability it would need to have without a liner. The barrel is a heat sink and "holder" for the wearable part. Try something if you want, but PLEASE get high res video of the explosion for us.

My most recent race engine build has aluminum sleeves and nikasil plating in OEM cylinders (not the big fin aftermarket cylinders). The aluminum liners have a larger diameter so the cases had to be bored out. I engaged Millennium Technologies in Wisconsin to do the work. The engine is 765cc with Venolia pistons and Total Seal rings to complete the package. The engine is very strong and I am impressed with the quality of Millennium's work and recommend them. Check out this link: www.youtube.com/watch?v=Rn53m2-TNSo

650performance said:

My most recent race engine build has aluminum sleeves and nikasil plating in OEM cylinders (not the big fin aftermarket cylinders). The aluminum liners have a larger diameter so the cases had to be bored out. I engaged Millennium Technologies in Wisconsin to do the work. The engine is 765cc with Venolia pistons and Total Seal rings to complete the package. The engine is very strong and I am impressed with the quality of Millennium's work and recommend them. Check out this link: www.youtube.com/watch?v=Rn53m2-TNSo

Click to expand...

And those sleeves are probably as long, or very close to the length of the oem steel sleeves for skirt support?

Millennium is used exstensively in 2 cycle world

Unfortunately, RD, I never had the opportunity to see the sleeves side by side, so I don't know the difference in length, if any. In response to my question, they did tell me that the overall rigidity of the barrel, case, sleeve assembly would match or exceed the OEM setup. I asked this because I wanted to get an idea of the potential for things squirming or shifting ... which impacts oil tightness and ring sealing.

Here's a interesting thread on nikasil

http://www.eng-tips.com/viewthread.cfm?qid=326233