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If we consider two engines one which uses sleeves/liners within the cylinders and one which doesn't use any sleeves. Then between these two engine blocks is it costlier to re-bore the cylinders of engine which doesn't use sleeves or is it costlier to change the sleeves of engine, assuming new pistons are used in both cases.

I guess re-boring a cylinder without liner should cost less since you only need to machine one surface i.e the inner surface. With liners you have to machine both the surface. Apart from that oversized pistons for re-bored cylinder may cost slightly more but I guess that doesn't cause much difference in cost.

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It's always going to be more expensive to put new liners into a block than just to bore it. The reason is, the number of machining operations is almost tripled with new liners.

Machining and processes to install new liners (might not be in this order):

  • Bore the original liners until they are paper thin, then removal
  • Install new liners
  • Bore new liners to size
  • Machine top of liners to match the deck height
  • Hone liners to match pistons

Machining and processes to bore cylinders:

  • Bore cylinder to size
  • Hone cylinder to match pistons

Plus you have the cost of the new liners which has to be added.

As far as pistons go, if you are buying pistons which are of the same make/quality/build, the price is most likely going to be the same between something which is standard and one which is oversized. There are exceptions, I'm sure, but not too many.

NOTE: All of the above is if you are considering the difference between adding new liners to a block which already has liners in it (came from factory that way). If you are putting liners into a block which didn't originally come with liners, or wasn't designed for replacing the liners (ie: GM LS V8 aluminum blocks), there's even more cost involved, because machining of these blocks is even more extensive.

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  • Why is it that we have to machine the original liners very thin before removal? Also in the case of dry liners it is also required to machine the outer surface of liners as well right? Oct 12, 2022 at 10:45
  • The reason to machine them to thin is it aids in the removal process without damaging the block to liner interface. If you drive out the old liners versus boring them, you will most likely damage this surface during removal, which will affect how the liner then fits. Some diesels (like Caterpillar) use liners which just drop in. No machining is required here. With dry liners, the outer surface should be an interference fit with just enough over they can be driven into place without too much fuss. These are most often frozen before fitment, which makes the process easier. Oct 12, 2022 at 11:04
  • If we hone a cylinder or liner without boring then is it possible to use current piston assuming it is still in good condition. Or does honing removing enough amount material that you always need to end up using an oversized piston? I guess the answer is more situational. Oct 12, 2022 at 11:39
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    It is most definitely situational, but you can "get by" in a lot of cases just doing a light hone on a cylinder and using the original pistons. Honing does take away material, but even so, if the end result is still within the specifications for the engine, it'd be fine. When doing a light hone, the idea is to take away as little material as possible while still "breaking the glaze", which is the smooth surface left behind after an engine is run for quite some time. Without the hone, new rings will not seat properly and the engine will be down on power because of it. Oct 12, 2022 at 11:45
  • If a linerless cylinder is bored, the engine's ruined. Three links discuss honing to renew these engines. Liners can be honed or bored. enginebuildermag.com/2016/04/honing-aluminum-blocks, mmsonline.com/articles/…, bimmerforums.com/forum/…
    – F Dryer
    Oct 12, 2022 at 19:57

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