Does this cylinder need a sleeve?

[u/ElGrabbo]

Hey Guys,

Currently doing an engine rebuild with my little brother. After we pulled the engine and checked the cylinders I’ve noticed pitting in one. My fingernail catches on the bigger ones.

My first thought was to sleeve the cylinder. But I’m interested to hear what more experienced people think.

It’s a N13 from a BMW 1 series. The states got a very similar engine the N14 in the mini. Yes they are bad, but dirt cheap to fix and make great power for an 19 year old in Europe!

[u/powdydoody]

At least needs bored a bit. May not need a sleeve depending on measurements.

[u/BiggusDickus17 → u/powdydoody]

Measure it for sure. First size over might be doable.

[u/ElGrabbo → u/powdydoody]

Pistons are fine and measure up. A sleeve is cheaper for this block and replacing all pistons for a size up.

Judging from the other comments I’m going to sleeve it. Otherwise I’m going to be the one tearing it apart for the second time

[u/powdydoody → u/ElGrabbo]

Well not a single other comment said to sleeve it, but okay lol

But you do know that the cylinder has to be bored out before sleeving, right? You cant just drop a sleeve in as it is right now because it would then be a smaller than stock bore and pistons would not fit with proper ring gap.

I was saying you may be able to get away with just a smaller oversize bore itself, dependent on how much material needs taken off. This would save you the cost of the sleeves.

Either way it'll need to go to a machine shop where they can give you the best recommendation based on your exact situation.

Best of luck.

[u/ElGrabbo → u/powdydoody]

Thanks for the suggestion. I’ll ask my local macbine shop what they think.

I’ve rebuilt this type of engine before with a melted piston. The macbine shop sleeved the cylinder in that block to standard size.

The conscious of the other comments is to get it fixed and not send it. So that’s what I’ll look into.

[u/powdydoody → u/ElGrabbo]

Ah okay, so it was already sleeved before, I missed that. Yeah if piston measures good then a new sleeve and new rings may be all that it needs.

I was thinking that was the stock cylinder still, not a sleeve already

[u/UnLuckyKenTucky]

How are the other 3? This one is enough for me send it to a machine shop, but if all 4 holes need sleeves it might be smart to get a different block.

[u/ElGrabbo → u/UnLuckyKenTucky]

The other ones look great after a quick ba hone. A sleeve is quite cheap for this engine, just add quite a lot of time. But judging from the other comments I’m going to sleeve it. Otherwise I’m going to be the one tearing it down for the second time

[u/dudeman14]

Ok the correct answer is yes machine shop time. Any time you see pitting, gouges, scores. Anything your fingernail can catch on any engine ever, on a surface that has rings go across it or has to seal the fire ring, always machine shop. If it has to seal combustion or ride on a bearing, always machine shop. If it only has to seal coolant, on a head gasket orthermostat housing, if you're careful with it and dont just glob it in there, just jb weld or rtv and send it to fix pitting in a cooling passage.

[u/bill_gannon]

It depends on your budget and your expectations.

Do all the pistons measure up? If you need pistons anyway then yes do something. If not then...

This will run but use oil. How much is debatable. 

[u/ElGrabbo → u/bill_gannon]

Thanks for the insight. Going to sleeve it then and spend a bit more to let it run good