1. Cylinder Blocks

2. Materials Cast iron Aluminum Economical More stable than aluminum
May use sleeves
Aluminum
Light weight
Uses sleeves

3. Cylinder Block Features
Cylinders – May be cast in or pressed in sleeves
Dry sleeves – no coolant contacts the pressed in liner
Wet 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 crankshaft
Skirted blocks
Non-Skirted Blocks
Deck
Water jacket
Mounting flanges

5. Disassembly and Cleaning
Mark all main caps for position and direction
Lubricate machined surfaces after cleaning to prevent rust
Remove 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 holes
Use additional crack detection methods
Magnaflux
Zyglo (dye penetrant)
X-Ray
Sono

7. Inspection and Measurement
Measure cylinder bores – correct problems by boring and/or honing
Size
Taper
Out-of-round
Surface finish
Scoring
Scratches
Washboarding (use a rigid hone to detect)

8. Boring and Honing
Boring enlarges the cylinder to a specific diameter to correct cylinder wear problems
Honing imparts the correct surface finish to the cylinder wall to ensure proper ring break-in, sealing, and wear
Torque 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 Angle
The correct angle for cross hatch lines to intersect is approximately 30 degrees.

11. Cross Hatch Angle
Too 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 Angle
Too 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 bores
Saddle alignment
Size
Taper
Out-of-round
Bore finish
Correct any problems by align honing or align boring
This 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 boring
Precision straightedge
Inspect the old bearings
Deck surface – Correct problems by machining ( this will affect compression ratio and valve to piston clearance)
Warpage
Parallel to crank centerline

15. Performance Modifications
De-bur block
Polish and paint lifter valley (only for high rpm use)
Restrict oil drainback from lifter valley to camshaft
Install drainback screens
Sono cylinder walls for maximum possible overbore
Install splayed main caps