Author Topic: Retrofitting a Zane 750S with cast iron liners - Your thoughts  (Read 281 times)

Offline ghwallice

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I'm stuffing around with my Zanes again, and I'm short of a set of aluminium/nikasil liners. They are available, but not cheap. Old mate that lives down the street from me is a fitter and machinist and owned a company for many years that overhauled hydraulic rams of all types and sizes, and he can make cast iron liners for very little cost.

I'm looking at using them in a track bike, initially...

Certainly there will be pros and cons.
I am led to believe that the materials for pistons for cast iron bores have a higher silicone content and a different expansion coefficient. Does this mean different clearances, and differences between cold and hot running (liquid cooled engines)
Are cast iron bores stronger and therefore could be over bored and allow bigger pistons to be used? (ie increased capacity)
Do they seal better and maintain better compression?

Or am I just being stupid, again... :(

Thoughts appreciated.

Regards, Greg
Do they wear out too quick, or wear rings and pistons too quick?

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Offline Paul H

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Re: Retrofitting a Zane 750S with cast iron liners - Your thoughts
« Reply #1 on: November 06, 2019, 11:41 »
First consideration for me Greg would be how much meat can be removed from the barrels before they too weak, maybe because you are getting close to an oil-way or a stud-way. i.e. is there even enough cylindrical space for a liner? This will limit your maximum liner thickness.

Offline sfcpiet

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Re: Retrofitting a Zane 750S with cast iron liners - Your thoughts
« Reply #2 on: November 06, 2019, 19:40 »
First consideration for me Greg would be how much meat can be removed from the barrels before they too weak, maybe because you are getting close to an oil-way or a stud-way. i.e. is there even enough cylindrical space for a liner? This will limit your maximum liner thickness.

Paul,

The liquid-cooled Zane engines have "wet" sleeves, they simply push into the barrel block and are held in place by the head and sealed with o-rings.  They are in direct contact with the cooling fluid.   Reckon Greg is looking to replace the stock alloy sleeves with cast-iron items.

There was a variant of the "Breganze" models intended for competition that were fitted with very thin cast-iron sleeves, so thin I could feel it "give" when I squeezed it!  These were bored out to something around 850cc.  No idea what type pistons were used, nor how reliable/unreliable they turned out to be.

I'd be loooking at ring compatibility and expansion rates, also at how evenly the cast iron sleeve is cooled to counter possible distortion if it turns out much thinner than the stock alloy sleeve.

piet
180s feel quick, 120s are...      If it ain't broke, fix it till it is.

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Offline hochkoenig

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Re: Retrofitting a Zane 750S with cast iron liners - Your thoughts
« Reply #3 on: November 06, 2019, 19:59 »

I donīt know anything much of Zanes, but why in hell they have Aluminum Liners and not like Guzzi and the rest platet Nikasil in the Cast of the Cylinders?
Anyway, Nikasil is the more advanced Stuff, the Piston slips easyer and the cooling is better on Alu.
Probably the Piston Rings differend than in Steel liners....
Usually the Nikasil has much more realibility, whats wrong on yours?

Offline ghwallice

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Re: Retrofitting a Zane 750S with cast iron liners - Your thoughts
« Reply #4 on: November 06, 2019, 22:06 »
Probably the Piston Rings differend than in Steel liners....
 whats wrong on yours?

My liners are either cracked, or damaged to the point where the nicasil cant be replaced.

Liner OD 90mm, ID 83mm, so wall thickness is about 3.5mm.

I was on the Bridgestone Motorcycle forum the other night, and the chat was that the earlier cast iron bores versus the later alu/nikasil had pistons with different silicon content. The cast iron had a higher silicon content, and required a looser fit to counter expansion. But there was no detail, so thought someone on this forum might know.



Kubota B7300
'54 Royal Enfield Meteor 700 (basket)
Some Laverda's and Guzzi's and Ducati's, my turbo KTM  & her KTM
Glass door beer fridge

Offline Grant

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Re: Retrofitting a Zane 750S with cast iron liners - Your thoughts
« Reply #5 on: November 07, 2019, 03:40 »
Why not fit another set of standard barrels.
Must be a few low mileage sets in breakers or fleabay.
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Offline Paul H

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Re: Retrofitting a Zane 750S with cast iron liners - Your thoughts
« Reply #6 on: November 07, 2019, 09:29 »
Hi Piet. Thanks for the info on the Zane's having wet liners. I didn't know they were that way, thinking they were sigle piece barrels. You learn some thing every day.  Paul