• Tech: Are cylinder sleeves bad for your M3 S65 V8 engine?

      There seems to be a bit of controversy surrounding cylinder sleeves and BMW engines. Oil consumption, excessive noise, sleeves dropping, Alusil blocks not liking sleeves you name it. I took some time to talk to our machine shop foreman, (the man with 50 years experience) Tony (VAC owner) and our manufacturing partners (Darton and LA Sleeve) about the drawbacks of using sleeves in the S54, S62 and S65 engines.

      Short answer: There are no drawbacks.


      Long answer: I can say with absolute confidence that properly specified sleeves installed properly will work flawlessly and offer more durability than a non sleeved block. Track builds, street builds, stroker builds, big HP forced induction builds not a problem. We have sleeved dozens of BMW engines in our machine shop and sold 100s of BMW sleeves to machine shops all across the world. We always have a few shelves full of BMW sleeves ready for shipment.

      Some quotes from our partners:
      The only drawbacks we are aware of are poor installation practices. Its the primary reason for almost every issue possible. Let me address that first: by adding a foreign object to the block, which had nothing in it to start with, logic would say the block has been compromised. That can be true if done incorrectly.

      Oil consumption is a myth. In many cases, oil consumption will increase as a result of sleeves because of an incorrect hone pattern. But, noise isnt a myth. If the sleeves are installed with too much piston to wall clearance, it usually sounds louder during warmup. It sounds louder as a result of iron lining the cylinders. Only way to prevent that is to watch the piston to wall clearance during the honing of the sleeves.

      Only other issue is the sleeves dropping Its rare but possible. Easily preventable, as long as theyre installed properly. Only thing that can drop the sleeves, even after perfect installation, is bad aluminum and/or when a block is overheated all while the head has been over-torqued. What weve seen happen when a block is way over torqued, and a customer is paranoid about head gasket seal, theyve over-torqued their head thinking it will seal water. So, when the heat expands the block, the block will pull away from the head. As that happens, the expansion along with the over-torqued head, it will actually push the sleeves down because the sleeves seem to rise at the same time. Very rare, but again possible.

      For all builds, we take it one step further by using flanged sleeves, built to our exact specs. These flanges assure that the sleeve will not drop under any circumstances. See pics below.

      When some mechanics or engine builders look at the deck of the S65, they think theres no room to put sleeves. Although the S65 does not have thick walls in between cylinder bores, it does have one good quality hard aluminum. If the sleeves are installed properly, the block looses no structural integrity. Meaning, the performance sleeves are quite thin, but radically stronger than the S65 aluminum. Therefore, by installing the thin wall sleeves properly, the great S65 block is now much more receptive to higher volumes of boost than the S65 alloy can handle. By simply lining the block with the thin wall, centrifugally spun-cast ductile iron sleeves, the cylinder bores can handle 50% to 70% more boost than that of the Alusil aluminum bore block.

      The boost can care less what pistons it runs with in most cases. Its the cylinder block walls that are compromised first, not pistons. If the S65 block aluminum is poor, it will fracture the block well before the pistons fail. Thats why we like to re-sleeve these alloy blocks ductile iron material. Not to save the pistons, but so the block can hold compression so the pistons do their job properly.

      There are several reasons for using cylinder sleeves. Most commonly they are found in manufactured aluminum blocks because as you know aluminum does not have the wear or sealing properties needed unless it is coated.

      In higher performance applications a ductile iron sleeve is preferred since they are at least twice the strength of a standard cast iron sleeve. If the sleeve is designed properly to fit the block the strength can actually be increased in the bore and ring seal is greater. You will also be able to run any style piston and ring that best suits the application. In some cases sleeved blocks will allow you to achieve a larger bore size or clean-up any damage that may occur. They can also be replaced in most cases.


      Yes, we sleeve Alusil engines with confidence.

      There ya have it direct quotes from BMW engine and sleeve experts.

      See more on our blog: http://www.vacmotorsports.com/blog/a...ur-bmw-engine/

      Flanged sleeves, made to exact VAC specs are measured before machine work starts.


      S62 block is honed and ready for the flanged cylinder sleeves.


      Very precise machine work is standard at VAC.


      Flanged sleeves are installed in the S62 block ready to be honed.


      S65 sporting VAC specified Darton flanged cylinder sleeves.




      Sleeved S65 on our RMC V40 machine.

      This article was originally published in forum thread: Tech: Are cylinder sleeves bad for your S65 engine? started by Mike@VAC View original post
      Comments 24 Comments
      1. Sticky's Avatar
        Sticky -
        THIS IS FANTASTIC!!! Putting it on the front page.
      1. singletrack's Avatar
        singletrack -
        Cool thread. Sleeving was very common, and effective, when I was into Subarus. Haven't seen as much on BMWs...

        With the stock S65s already handling pretty big power, what's the new goal for the sleeved block?
      1. Mike@VAC's Avatar
        Mike@VAC -
        Thx guys.

        New goal? No idea. We sleeved a few for big boost applications, not sure what happened with those.

        We are building a sleeved, high compression n/a, Pectel controlled race only S65 now. We will be running that on an engine dyno...should be cool. If the client is OK with it I will photo/video that whole program and share dyno sheets.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Mike@VAC Click here to enlarge
        We are building a sleeved, high compression n/a, Pectel controlled race only S65 now. We will be running that on an engine dyno...should be cool. If the client is OK with it I will photo/video that whole program and share dyno sheets.
        We would all love to see this. Hope he's cool with it.
      1. LostMarine's Avatar
        LostMarine -
        Nice! I wanna stop by and see this stuff up close.
      1. Mike@VAC's Avatar
        Mike@VAC -
        I will check tomorrow on status. I think the n/a screamer is done, or close to done.
      1. Sorena's Avatar
        Sorena -
        Great stuff.

        That sleeved NA S65 goes to Lebanon, right?
      1. s62's Avatar
        s62 -
        My S62 engine was sleeved in 2006. Boosted to .6 bar and has put on
        50.000 trouble free km since. Its been driven hard, Nurburgring laps,
        drifting, 300 km/h Autobahn runs, quarter mile, you name it - no garage queen.

        Id say sleeves are pretty much bullet proof.
      1. akh23456's Avatar
        akh23456 -
        Click here to enlarge Originally Posted by s62 Click here to enlarge
        My S62 engine was sleeved in 2006. Boosted to .6 bar and has put on
        50.000 trouble free km since. Its been driven hard, Nurburgring laps,
        drifting, 300 km/h Autobahn runs, quarter mile, you name it - no garage queen.

        Id say sleeves are pretty much bullet proof.
        what were you boosting before your sleeved motor? or how much boost did you raise after the sleeved motor?
      1. ERM324's Avatar
        ERM324 -
        Click here to enlarge Originally Posted by Mike@VAC Click here to enlarge
        Thx guys.

        New goal? No idea. We sleeved a few for big boost applications, not sure what happened with those.

        We are building a sleeved, high compression n/a, Pectel controlled race only S65 now. We will be running that on an engine dyno...should be cool. If the client is OK with it I will photo/video that whole program and share dyno sheets.
        Honestly I've seen absolutely nothing but great things come from you guys - looks like a great shop and would love to swing by.

        Great product!
      1. s62's Avatar
        s62 -
        Click here to enlarge Originally Posted by akh23456 Click here to enlarge
        what were you boosting before your sleeved motor? or how much boost did you raise after the sleeved motor?
        I was boosting a little less, probably 0.5.
      1. Mike@VAC's Avatar
        Mike@VAC -
        Click here to enlarge Originally Posted by ERM324 Click here to enlarge
        Honestly I've seen absolutely nothing but great things come from you guys - looks like a great shop and would love to swing by.
        Great product!
        Pls do, it's always cool to have a heavy hitter stop by Click here to enlarge

        Click here to enlarge Originally Posted by s62 Click here to enlarge
        My S62 engine was sleeved in 2006. Boosted to .6 bar and has put on
        50.000 trouble free km since. Its been driven hard, Nurburgring laps,
        drifting, 300 km/h Autobahn runs, quarter mile, you name it - no garage queen.
        Id say sleeves are pretty much bullet proof.
        Awesome.

        Click here to enlarge Originally Posted by Sorena Click here to enlarge
        Great stuff. That sleeved NA S65 goes to Lebanon, right?
        This specific one is going a bit south east of Lebanon Click here to enlarge It's in the diamond hone now, should be going together soon.

        Click here to enlarge
      1. flipm3's Avatar
        flipm3 -
        I love seeing motor tear downs and rebuilds! Keep us posted with more photos if you can. Click here to enlarge
      1. Mike@VAC's Avatar
        Mike@VAC -
        Click here to enlarge Originally Posted by flipm3 Click here to enlarge
        I love seeing motor tear downs and rebuilds! Keep us posted with more photos if you can. Click here to enlarge
        For competitive and personal reasons, many clients don't want me taking pics (even if the name is not shared) Trust me, I try every time Click here to enlarge Upon assy I can photo this one tho.

        4.4 VAC stroker, Xforged CPs, Carrillo/CARR, Schrick cams, Stage 3 head and more.
      1. flipm3's Avatar
        flipm3 -
        Click here to enlarge Originally Posted by Mike@VAC Click here to enlarge
        For competitive and personal reasons, many clients don't want me taking pics (even if the name is not shared) Trust me, I try every time Click here to enlarge Upon assy I can photo this one tho.

        4.4 VAC stroker, Xforged CPs, Carrillo/CARR, Schrick cams, Stage 3 head and more.
        Totally understandable.

        My dream is to build and stroke my E46 M3 and E90 M3. I just have to figure out how to save up that coin first, haha.

        Great stuff man. Keep up the work.
      1. benzy89's Avatar
        benzy89 -
        Everything is sooo prettty Click here to enlarge
      1. DBFIU's Avatar
        DBFIU -
        Awesome article. One question, why was the block itself honed if it was going to be sleeved anyway?
      1. Mike@VAC's Avatar
        Mike@VAC -
        Click here to enlarge Originally Posted by DBFIU Click here to enlarge
        Awesome article. One question, why was the block itself honed if it was going to be sleeved anyway?
        Ancient jedi trick Click here to enlarge
      1. DBFIU's Avatar
        DBFIU -
        The force is strong with this one.
      1. vasillalov's Avatar
        vasillalov -
        Interesting that the S65 is closed deck and the N54 is open deck...