Hey guys, im in the process of tearing down my engine for a rebuild (98 f3). Getting a 2mm overbore along with other things. But i was wondering if the cylinders have the nikasil coating on them? would it be needed after the overbore? or is the guy I talked to at the shop full of sh**?
thanks.

 

It's likely that it has a nikasil coating as it's aluminum. Very likely. It would be a good idea after the overbore.

 

It definetly isn't nicasil. Honda uses alusil which isn't a plating at all on never models but i checked ronayers fiche and they have 0.25, 0.50, 0.75 and 1 mm oversize piston straight from Honda so probably it has iron sleeves which can be bored and honed whitout any plating. Whit 2 mm overbore you will probable need new sleeves if anybody sells 2 mm oversize pistons.

edit. checked JE and Wiseco and they bouth sell 2mm oversize pistons. Just boring was on the sidemark at Wisecos site so you won't probably need new sleeves.

 

No. You absolutely have to do it.


==OR==

Get a steel sleeve pressed in.



But you could in no way run with just an aluminum cylinder with a straight bore

 

And Mika is right - OEM is alusil. Nikasil is better

 

Are you sure it hasn't iron sleeve? The 929 was the first Blade that had alusil. Older carb Blades use steel/iron sleeves.

 

Yes. You're right, it is a steel sleeve for OEM.

 

So in short, what I was trying to convey is that if you don't run a steel sleeve, you need plating. If it's a steel sleeve - you don't need it. Hence my "==OR==". But if nothing is majorly wrong with the sleeve, they can probably just bore it, then hone/hatch and you're good to go.


What probably happened was the machine shop saw the aluminum casing and though "oh, it's aluminum, probably lined - we can't do the plating"

 

Ok

I don't understand why machine shops don't order plated sleeves somewhere and do the job themself. Sleeves are allso made out of billet aluminium and ceramic composites so they are stronger and lighter then oem cast aluminium that they grind/bore of the casing to get the sleeves in.

They used sleeves whit zx-14 to get strength to the casing but i think they were iron.


Sorry the OT!

 

thanks for the info guys. now i want your oppinions, is the over bore worth it? the shop i went to quoted me $500 for the bore/nikasil.
or should i leave it how it is and just continue with my other build plans?
My other plans for the engine is, port and polish, lightened crank, f4i intake cam, f3 intake on exhaust side, and adjustable cam gears.