Nicasil VS Iron bore

[LWC82PE]

Ok so the facts are

1 - you can get iron bores coated but it has to be done in Nickel silicone carbide
2 - Nickel silicone carbide is the same as Nikasil

Has anyone here had a cast iron barrel done and was happy withe the results?

Is there a place in USA that does a good job?

Its no more of a hassle for me to send a barrel to US then is is to NZ

My main reason for looking into it is if it makes the bore last longer and you dont need to get re-bores so often

[Lozza]

Thats the idea of plating you no longer need to rebore.....ever the piston wears NOT the bore. US companies have dropped the ball some what lately. You can try Millenium.

[GMC]

Aluminium cylinders are too soft as standard to cope as a cylinder which is why they need to be hardened.
I think a lot of cheap lawn mowers used to run non hardened alloy cylinders as they weren’t meant to last very long.

I don’t think chrome bores were very successful, Honda only tried them for one model I think, maybe Yamaha too??

Electrofusion is a Kawasaki thing, I read somewhere they explode carbon rods inside the cylinder with several thousand volts to harden the Aluminium
They’ve been using them since around mid seventies.

Nicasil is probably the most common as several makes use it these days.

Not sure about the worth of applying Nicasil to a cast iron sleeve,
You would get longer wear but all the other benefits of less weight and heat transfer would be lost with the cast iron sleeve.

[Mick22]

No good coating work done here. End of. Any ring that is good for cast iron is good for Nikasil. Rings for 'chrome' bores (actualy same as  hard chrome on forks)  has a grey ring with no coating on the ring face.
Here is an example of good plating ie you can clearly see the bridge has been relieved BEFORE coating. The post plating honing has not touched the bridge(you can still see the machining marks) and the port windows have been correctly  chamfered again before plating.
Try NZ CYLINDERS(use the UK Langcourts process) Grant over there does very good work is a little on the expensive side. They have excellent customer service and will accomodate 'hot potato' jobs for customers here.

Hey Lozza, you've caught my interest with that photo, why do they have to releave the bridge? Its interesting because I had a KX500 cylinder plated by Mahle back in the late eighties and it seized within a few laps on the bridge it all measured fine prior to instillation and I could never get my head around why it had seized

[Mick22]

Aluminium cylinders are too soft as standard to cope as a cylinder which is why they need to be hardened.
I think a lot of cheap lawn mowers used to run non hardened alloy cylinders as they weren’t meant to last very long.

A bit of trivia on aluminium cylinders, A friend of mine worked on a project for Alcoa in victoria a while back on a new aluminium alloy casting material. It was to be used for casting  motorbike & car aluminium cylinders / blocks that could be direct bored without a sleeve or liner. It worked! they had engines running on dyno's for years on end and worked well. Like a lot of tech out there it worked well but obviously didn't work out on some bean counters calculator

[vmx42]

I remember a Motorcycle News project bike - 900cc Honda Fireblade from memory - and the story said that it's cylinders were not plated. Could have been a typo, but they made a bit of a fuss about it.

Seemed strange at the time.

[whitey 43]

The exhaust side of the motor is the hottest...That little bridge in the exhaust port heats up way quicker than the rest of the cylinder & expands faster, grabbing the piston...Commonly called a "cold seizure" because it happens soon after fired up.That is why the bridge port should be relieved when rebores are done.Pretty common on Kawasakis.You can also drill 3 small holes in the piston in line with the bridge to help too.

[Mick22]

So does a nikasil bore make it more likely to occur? or is it mainly a Kawasaki thing?

[whitey 43]

Mainly kwaka thing (from my experience) but can happen to any 2 stroke with a bridge port exhaust...Using hi quality oil helps prevent these nasty problems too.

[Hoony]

So does a nikasil bore make it more likely to occur? or is it mainly a Kawasaki thing?

happens on all bikes with exhaust bridge

[Lozza]

Geoff most cast in iron sleeves have quite good heat transfer, the sleeve is very rough and has ribs on the outside of the sleeve. Then the cylinder is cast around that, it gives superior heat transfer to a press in sleeve. Yamaha were the first to perfect the process.

Other Jeff yes I remember that project it had 'a coating' on the bore but was not Nikasil, the rings also had a special coating on them also.

Bridges that grab have not been relieved or they have been thinned to much.

[Freakshow]

I just blew up my mculloch chain saw, i pullled it down ( probally only 10 hours since new and the piston is rooted on the ex side and has dragged the barrell with gouges.  What i cant see is any sleeve or lining in the barrell, it looks to be just stright alloy, not even a coating? im wondering if they just missed mine on the production line or what.  the mower man says it has one, but yet he cant show it too me so i think he fishing on what hes seen previously not what he can see, if it has any kind of coating its in the material as there is nothing on the top surface.   

The barrell looks like it was made out of ali cans, and the pistons not much better, havent got back to me with price of a barrell yet, but me tinks its all over red rover, and be cheaper to buy one of them china copies and save me dough...... :'(

[Rossvickicampbell]

Freaky - I'm sorry mate - your avatar is doing my head in - can you get rid of it