THIS IS PROBABLY AND IMPOSSIBLE QUESTION!!
but i'll ask anyway. lol


Generally speaking, How bad do Cosworth Cylinder
bores wear, due to milage? (120k)
shes starting to use a bit of oil so im doin the lot
(personally im starting to think its more likely to be the turbo thats fooked lol)

as i wanna know if i should be expecting to buy .5 pistons
with my engine re-build bits.

I realise it would need to be done if the bores are scored.
but do bores wear that much?

 

i dare say it can depend on all sorts of conditions but i just did a rebuild on my K reg 4x4 saph done 94000 miles and it has a .5mm rebore to get it spot on

 

cheers mate.

hmmm, wondering weather i should just order .5 pistons now really.

as it hasnt been rebuilt before. infact, only ever had the head gasket done once!!

 

would order .5mm pistons.
Got to be some bore wear after that mileage,so at least you can get the block bored and honed to factory clearance.

 

id get the head off and check the bores before you order em up. you'll get away with a hone if theyre not scored or pitted. ignore the lip on the top of the cylinders, thats carbon build up not how much the bores been worn down!

if it was just using a bit of oil every few hundered miles then i doubt theyre bad enough to NEED a rebore.

 

thanks mate.

i will get the bores measured,
it uses just over a litre every 1000 miles now.
but as i say, i REALLY wouldnt be surprised if a lot of that is turbo.

hmmmm have to wait then and just budget for pistons i guess!

 

thats quite a lot of oil !!

 

thats not bad at all - -in the handbook (and this is from new!) it states that it may use upto 1 litre of engine oil per 1000km or 600 miles - -so 1 litre in 1000 miles is pretty good IMO

 

Id of never of thought that. Will check mine now as ive never really thought about it each time i top up. Is it down to the turbo then ?

 

the turbo and the pistons i think,

a mate fitted cossie pistons to his rebuilt 4G63 evo engine - now my evo didnt use a drop of oil between 3K services, but his used about half a litre per 1000 miles which is a lot from nothing IMO