Nikasil V re sleeve?

[D project]

What's people's preference? What sort of lifespan do you get out of a nikasil bore? Or is it better/cheaper to just put a new sleeve in and re bore when required?

[Hoony]

My take from experience is get it nicasil. i have had a CR250RG for 28 years. in the early day the nicasil wore off and there was no one in Oz that did it so i bought a new cylinder, next time around i got the old cylinder sleeved (serco) and i could feel it was not as fast as the lined cylinder for some reason (maybe heat transfer)  i have since had electrosil do 3 more and always happy with them.

[SUZUKI311]

I agree with Hoony, Nicasil every time. Sleeving has its place, but not to replace original coatings. I only use Electrosil for customer bikes, in the early to mid 90s I used Aurum plating in Qld, and the job was very second rate, and the coating failed immediately. Electrosil's work is excellent to say the least, never had one fail yet.

[William Doe]

Think of it like this , no matter how bad you break a leg would you consider having it amputated and replaced with an artificial one or would you rather keep your body as designed even if it meant more expensive surgery every few years .

Sleeving plated cyls is reverse engineering at its worse, if possible always replate .
 

[Tomas]

What's people's preference? What sort of lifespan do you get out of a nikasil bore? Or is it better/cheaper to just put a new sleeve in and re bore when required?

That depends on what your cylinder has. Some have cast iron sleeve others are plated cylinders. I like cast iron sleeve since you can bore them out to fit oversize pistons. They are not as hard and last as long as plated cylinders but are more forgiving. At the end when you wreck your nicasil sometimes you have no other choice but slip an iron liner in it to be able to save it . Cylinder plating is just next step in engine development and since there is no need for tight tolerances(interference fit liners) and more comlex casting proces(cast in liners) manufacturers novadays use plating/coating since it is cheaper and quicker. How long you cylinder last depends on how well you look after your bike.

[Lozza]

Sleeving a cylinder that was designed around nicasil is a highest order bodge there is. Every one I have seen sleeved ping their heads off when hot to varying degrees. There is no reason to do it when costs are the same(cheaper sometimes for plating) I have yet to see a cylinder that couldn't be repaired. Replating has one downside stud holes can go 'soft' after 2 replates but thankfully there is a great work-around. Making up some dummy aluminium studs to go into the stud holes through the plating process ensures the threads are left in tact

[GMC]

I like cast iron sleeve since you can bore them out to fit oversize pistons. They are not as hard and last as long as plated cylinders but are more forgiving. At the end when you wreck your nicasil sometimes you have no other choice but slip an iron liner in it to be able to save it .

You can also bore a Nicasil cylinder to oversize and then get it replated if there is deep damage in the cylinder
It's expensive but they are long wearing, just replace pistons to keep the motor in spec as the piston cops the wear.

They are mortal though, if you neglect your filter or lunch a bottom end they will damage like anything else

[Lozza]

...............  also it's possible to plate over a cast iron liner, the most I have heard of is 0.8mm of plating reducing the bore by 1.6mm easy enough to take you back into standard or oversize range of pistons.

[sleepy]

What's people's preference? What sort of lifespan do you get out of a nikasil bore? Or is it better/cheaper to just put a new sleeve in and re bore when required?

Despite all the negative comments there are a lot of motors out there in the real world that have been sleeved. If they are fitted properly and port match properly they work just as well as the plated cylinders and you can get up to 4 oversizes for some models. Normaly an increase in a couple of jet size is required and a little extra oil helps as well. If there is only 1 size of piston available then get it plated. The Iron bore will only last about half as long but with 5 different size pistons it is more economical.
You should tell us what type of bike you have because some shouldn't be sleeved. Also what you are going to do with it after.

[D project]

Thanks for all the info. Bike is pre 90 RM125. I've never had any experience with nikasil bores and heard they can be expensive to have re done $400? As opposed to re sleeving $250? Providing my own sleeve. I thought as it's going to be used/raced on the long term it may have been more cost effective. But it looks like I'm heading towards the nikasil option.

[Lozza]

If you buy a sleeve costs will be the same, plus when the time comes for a rebore you pay for a piston AND the rebore, nicasil you just buy the correct piston install and forget. Depending on where you send the cylinder to here or o/s $350-400 for a straight replate is about right.
That RM will ping badly with a sleeve.

[William Doe]

What's people's preference? What sort of lifespan do you get out of a nikasil bore? Or is it better/cheaper to just put a new sleeve in and re bore when required?

Despite all the negative comments there are a lot of motors out there in the real world that have been sleeved. If they are fitted properly and port match properly they work just as well as the plated cylinders and you can get up to 4 oversizes for some models. Normaly an increase in a couple of jet size is required and a little extra oil helps as well. If there is only 1 size of piston available then get it plated. The Iron bore will only last about half as long but with 5 different size pistons it is more economical.
You should tell us what type of bike you have because some shouldn't be sleeved. Also what you are going to do with it after.

Sounds like a dream run , more oil , re jet , hope that who ever does the job actually fits it properly and aligns the ports and pegs it so it wont move. Then you can spend time making sure the ports are chamfered properly after each rebore and that you have given enough clearance on the Ex bridge if your cyl has one .Then all you have to do is take it out and carefully run it in , ideally after an initial run pull off the cyl and clean up any high spots on the piston . You will still have something that wasn't designed to run an iron sleeve in the first place , but it will be so much cheaper than re plating and just fitting new rings and pistons at correct intervals  .

If cast iron sleeves are so good why don't they fit them ex factory any more 

 

[Mike52]

If cast iron sleeves are so good why don't they fit them ex factory any more 

Price/profit ? Laziness ?  No tradesmen left who know how to do it ?

The sleeve in my 85 and 86 Husky's and 69 and 76 Ts Suzuki's look to be satisfactory and have done exactly what they were designed for for a  very very long time.

If you want to use that logic then where are all the early chrome bore Kawasaki's ?

 

[Lozza]

If you want to use that logic then where are all the early chrome bore Kawasaki's ?

They just got replated and now run on nicasil same as the early TA/TZ yamaha's. Porsche must have got it all wrong using nicasil on their air cooled 917 race cars and 911 road cars,maybe Ferrari did to for their F1 and road cars?

[Mike52]

If you want to use that logic then where are all the early chrome bore Kawasaki's ?

They just got replated and now run on nicasil same as the early TA/TZ yamaha's. Porsche must have got it all wrong using nicasil on their air cooled 917 race cars and 911 road cars,maybe Ferrari did to for their F1 and road cars?

How long between rebuilds on that Ferrari F1 engine ?