This is the crankshaft from my original engine - S18K - and was relatively clean to start with.
Big end journal sludge trap caps are readily accessible. Having removed the split pin,nut and centre bolt the caps can be tapped out. The centre hole is 0.25" diameter. I made a drift from an old screw driver by cutting off the blade and grinding the end into a dome to avoid damaging the cap interior.
Main bearing trap caps are not quite as easy to get at. Oill passages are drilled through the balance arms and then blanked off. 8 of the passages are blanked with a bolt and tag washer as shown in 'A'. The remaining 4 passages are underneath the balance weights which must be removed to gain access. All passages will be blocked with sludge.
If the caps are not seized they can be eases out by inserting a small screw driver down the oil assage and twisting as shown at 'B' in the picture.
|Two big end cap assemblies still covered in sludge.|
|And this is what the trap looks like when the caps are removed.|
|The sludge filled about one third of the diameter across the width of the trap ('A'). To remove the bulk I used the back of part of a hacksaw blade ('B') and slid it round the circumference. (I also ground away the teeth to avoid cutting myself.)|