Here are a few pic of my bearings and crank shaft journal. Again thoughts please, presume wear is excessive. I measured journal at 42.00 41.99 and bearings at 42.05 average (got 42.04 - 42.06 in places). First I presume the clearance for the big end is "diametrically" i.e. 42.00 - 42.05 = 0.05, possibly up to 0.07. I will polish the journal up and see what that's like. Has any one tried the toyota 4A-GE bearings. Clearance is 0.024 - 0.056. Watching Andy's M O when he put the above half bearings in he thought 0.024 was a bit tight and put originals back. Any thoughts on this. All comments welcome. Cheers Gaz
Hey Gaz, youre testing my memory here, cause I did mine years ago, but I got OE shells from Ducati (Stein Dinss perhaps) i cant remember what I measured but if theres any doubt then get them swapped out for new. It would be a shame not to sort everythin whilst the engine is apart. I dont know either about the Toyota shells, however, someone recommended Toyota piston rings for my 650 Cagiva(Ducati) engine. It ran but burnt loads of oil. Smoky as hell. The rings seemed the same size but the ring gap was bigger (marginally) than OE. Got new rings from Gowanloch and its sorted now. No oil. My point being, make sure that the part you are getting fits properly! I would just get the Ducati ones, although I know they are expensive. Not sure if any of that helps at all
Here are the Ducati shell sizes, only a fraction of a thou between them, you can mix the blues and reds to get the desired clearance, 0.0015 of the top of my head. Check your clearance with the plastiguage. Your Conrods have a letter engraved to show the size too. All available from Ducati at about £25 per shell.
I can't advise on the crank journal, doesn't seem too bad though, maybe try the polish then see where it's at. When I split my M900 engine I noticed the big end shells were showing a bit of wear and some scoring. I didn't have a big enough micrometer so I used plastigauge on the old shells, it was still showing within spec so I just ordered some new ones using the part number on the back. These came from a 35,000k engine.
Thanks Paul, Desmo & Mnine. Got some plastigauge on order. Conrods are B with yellow paint, crank has -2B written on it and a 2 stamped in it. Regarding small end Pin is 19.00/18.995 Bearing 19.015 (manual says bore to 19.015 - 19.028) that end looks OK. Cheers Gaz
Ok got some new bearings. Putting the crank cases back together and shimming. I had a gasket I ordered a while ago as a spare. I have come to put it in and noticed an extra hole in the gasket, can anyone throw any light on this. Cheers Gaz
No, but Im not surprised as the case are very similar for different models. My own cases are from an ST2, long story.... So there may be a slight difference, I wouldnt worry, itll still seal. Maybe put a dab (small) of gasket sealant in there if you are at all worried.
Desmo , Yes I was going to fill the gap with three bond, but just wondered what bike it was from. I emailed Baines (who I bought it from ) but have had no reply, will have to give them a call. Cheers Gaz
When I rebuilt the engine the first I did not change the bearings, they had done approx 12k and I thought they would be OK. So during this latest strip down I found this. Again, I am not really sure why I decided to strip it, apart from it just wasn't sounding quite right and I thought I had bit more vibration than usual. I am not sure if this is the culprit but it would not have helped. Anyone's thoughts on whether this is significant enough to cause running problems. Cheers Gaz.
so it seems there are 6 different sizes of these, how do you know which one to put back, just by using same part number??
Sorry. Initial post was con rod half round shell bearings. I got some of those sorted. The last picture was of one of the crank shaft angular contact bearings. Sorry for confusion. Cheers Gaz
I think (will stand to be corrected) you measure the crank shaft and or use plastigauge and see if the standard bearings (red) gives desired clearance 0.024 - 0.056. If not its a regrind and undersize bearings. Cheers Gaz
Thought that was what they were. Anyway the track is spalling and probably the balls as well so unfortunately they are toast.
