While building the cafe racer engine I bought a crankshaft off ebay and fortunately, the big ends only needed a polish. The sludge trap looked clean but I thought I'd take it out for a check- unfortunately, a previous owner had drilled the trap, possibly to increase flow, so the sludge had actually built up between the outer face of the trap and the crankshaft bore, which locked the trap in place pretty effectively. Removal involved using a 12mm fine tap to create a thread in the trap and then buying a length of studding with the correct thread, which was fitted into the trap and the other end clamped in a vice with the adjacent face of the crank driven using a brass drift and a copper mallet. The sludge was rock solid and needed scraping (and chiselling!) out but it all cleaned up in the end. The replacement trap was smaller in diameter but fit o.k. and I'll be using detergent oil. The feed from the end of the crankshaft was also blocked and needed cleaning with penetrating oil and wire- well worth checking if you're doing a rebuild. Onward and upward! MikeJ P.S. I also initially fitted the big end caps the wrong way round and wondered why the new bearings were a bit tight!
It's quite normal for sludge to fill the outer cavity and even block off 2 of the four journal holes and it's usually just after this that the rods let go and fight there way out through the cases lol congrats on doing the job properly
Hello, wow, that's one blocked sludge trap! Thanks for the tips on the filters. I was looking at your thread Darkman and was wondering who does your chroming ? - they do a really nice looking job. Fortunately, there's not a lot of chrome on my cafe racer so it'll keep the costs down but it would be useful to know, Cheers, MikeJ
