2 Materials Cast iron Aluminum Economical More stable than aluminum May use sleevesAluminumLight weightUses sleeves
3 Cylinder Block Features Cylinders – May be cast in or pressed in sleevesDry sleeves – no coolant contacts the pressed in linerWet Sleeves – Coolant runs directly on the outside of the sleeve (some form of seal needed) example: Cadillac 4.1L
4 Cylinder Block Features Main web – the area that supports the crankshaftSkirted blocksNon-Skirted BlocksDeckWater jacketMounting flanges
5 Disassembly and Cleaning Mark all main caps for position and directionLubricate machined surfaces after cleaning to prevent rustRemove and save all plugs (note locations)Before assembly, wash with hot soapy water
6 Inspection and Measurement Visually check entire block for cracks, excess casting flash, or damaged bolt holesUse additional crack detection methodsMagnafluxZyglo (dye penetrant)X-RaySono
7 Inspection and Measurement Measure cylinder bores – correct problems by boring and/or honingSizeTaperOut-of-roundSurface finishScoringScratchesWashboarding (use a rigid hone to detect)
8 Boring and HoningBoring enlarges the cylinder to a specific diameter to correct cylinder wear problemsHoning imparts the correct surface finish to the cylinder wall to ensure proper ring break-in, sealing, and wearTorque plates should be used when honing cylinders“Hot Honing” is beginning to be used to simulate the distortion caused by engine heat
10 Cross Hatch AngleThe correct angle for cross hatch lines to intersect is approximately 30 degrees.
11 Cross Hatch AngleToo flat a cross hatch angle can hold excess oil which causes thicker oil films which the piston rings will ride up on or hydroplane. Excessive oil consumption will result.
12 Cross Hatch AngleToo steep an angle promotes oil migration down the cylinder resulting in a thin oil film which can cause ring and cylinder scuffing.
13 Inspection and Measurement Measure main bearing boresSaddle alignmentSizeTaperOut-of-roundBore finishCorrect any problems by align honing or align boringThis will move the crank and cam centerlines closer together and may cause timing chain to be loose
14 Inspection and Measurement Check camshaft bore alignment- correct by installing semi-finished bearings and align boringPrecision straightedgeInspect the old bearingsDeck surface – Correct problems by machining ( this will affect compression ratio and valve to piston clearance)WarpageParallel to crank centerline
15 Performance Modifications De-bur blockPolish and paint lifter valley (only for high rpm use)Restrict oil drainback from lifter valley to camshaftInstall drainback screensSono cylinder walls for maximum possible overboreInstall splayed main caps