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Old 10-07-2012, 03:21 PM   #22
HPF Chris
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Join Date: Feb 2006
Location: Portland, OR
Posts: 3,684
My Ride: 2002 M3, 2006 530i
Originally Posted by FragNasty View Post
+1 to no sleeves! It's too bleeding edge for anything that's not a garage queen or a car that is part of a race team prepared to swap motors. I don't believe the stage 3 kit even requires sleeves. It's an option that reduces displacement (and power) with the intention of thickening the walls between cylinders because of fears that the head gasket may fail at those points.

IMO It's just another thing that can give problems (if they move). The S54 with the L19's over-torqued has addressed the gasket issue; there haven't been any members complaining about blown head gaskets or heads lifting with that setup.

Adding sleeves, which will weaken the block (side effect of the extensive over-boring requirements to insert the sleeves), and the L19's and the extra torquing and you have a recipe for unwanted headache possibilities [in cylinder #5]! (

So why try to solve a problem (thinner walls between cylinders) before you can even confirm it's actually a problem? Enjoy the 3.4 displacement and the extra power that can be had with a setup that hasn't proven to be anything but reliable.
Many of the builds that we've done have sleeved blocks. They are definitely much stronger than a .020" overbored block. Many of the motor failures we see have a small crack in the side of the cylinder wall. What can cause this is the head lifts, coolant flows into the cylinder and the side of the cylinder wall breaks into the water jacket. A sleeved block will handle this scenario much better and we've never seen this occur in any of the sleeved blocks we've done. However that is a condition that shouldn't happen in the first place if the tune is dialed and the head is on tight with ARP L19's. The sleeved block is a much better solution however it is mostly not necessary unless you're wanting really big numbers (over 900rwhp-1000rwhp), have already bored .020" over and need to re-bore, or just want added insurance.


Last edited by HPF Chris; 10-07-2012 at 03:22 PM.
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