Badly Smoking 1098

Mini Technical Sections Problems, Questions and Technical
1

Can someone please help :confused:

I recently bought a low mileage 1098 off eBay never knowing if it ran just taking it on the blokes word (completely the wrong thing to do I know) after fitting it and taking it to southam mini centre we found that the oil control ring on one of the pistons was leaking quite badly…

However…

it holds its compression and pulls like a train and for £89 I’m not too upset, before I fitted the engine however I checked the cylinder wall which showed no step and looked brilliant however the piston which is leaking had dints all over the piston top face lean running?? A dropped valve??

I want to do this myself as I am comfortable in doing it however when talking to southam who said that if it did not take new rings a re-bore would be needed, however I am very tempted to re-bore as the piston had 80% leak and due to the piston dints however I am unsure if it is needed??

What would be the best thing to do??

2

You can just try a new piston in that bore - and see if it works. Lift the head and pop the engine out - leave the gearbox in place. Swap the piston - have a look at the crank bearings and decide if they are ok (is the oil pressure good??) and then pop the engine back in. Easy day’s work if you don’t hang about.

3

the oil pressure seems to be slightly low so was planning on changing the oil pump at the same time whilst the engine would be out, I have found that +.060 " pistons are cheaper would I be able to bore straight out to fit these pistons??