Main Bearing Shells proud of Crankcases

[simco1964]

Hi Everyone,
                   In desperate need of advice, fitted new Main Bearing shells as per Markings, plastigage all and there all reading o,063+ and 1 which has the Black shell fitted is reading 0,076 (photo included), but what I have noticed is that all the shells are proud of the crankcases, is this right? (See photos).

Regards
Simon

[royhall]

No not right they should be level with the castings. You do appear to have a fair bit of muck around the crank area, are you sure the castings are totally clean under the shells, and the casings haven't been painted under the shells. You also appear to have a very rough crank journal  in the Plastigauge photo.

[simco1964]

Hi Roy,
           The crankcases i'm sure are clear of any paint etc.
 Have double check crankcases and their definitely clean!! I didn't know whether they had to be  slightly proud for the jointing compound? plus i don't know whether they compress slightly into the casing when I torque the bolts up? as for the journal I don't know what's good/bad,can't feel any grooves/ridges with finger nail, it is quite a close up photo with the sunlight on it, don't know whether thats making it look worse than it is.
Whats the best way forward?

Regards
Simon

[royhall]

Your probably best taking some clear photo's of your crankshaft in good light, and posting them on here. We will know better then. Where did you buy your shells from?

[simco1964]

Hi Roy,
          Bearing Shells have came CSMNL, will take some more photo's of Crank and the casings without the shells in, so you can see the condition, many thanks for all the help so far!
Regards
Simon

[simco1964]

Hi Roy,
          Find attached Photo's of crank etc, may have to 2 Posts for all the Photo's.
  Have taken a couple of side Photo's of shells in casing, see what you think? it looks like to me if the shells are not tight to the casing at the bottom? or is it just an optical illusion?

Cheers
Simon

[simco1964]

More Photo's

[hairygit]

Try fitting the bearings to the top casing as well, then place on top of the lower casing, and GENTLY push them together, the chances are the bearings will push down into the correct location, but do be gentle, as you don't want to damage the shells trying to force them.

Sent from my X6pro using Tapatalk

[simco1964]

Hi Hairygit,
                When assembling casings as you've explained, do I fit bolts and torque as per Haynes Manual?
Regards
Simon

[hairygit]

You can do, but even just pushing the casings together and having a look should give you an idea of what's going on.

[simco1964]

OK, will give it a go

[royhall]

Try fitting the bearings to the top casing as well, then place on top of the lower casing, and GENTLY push them together, the chances are the bearings will push down into the correct location, but do be gentle, as you don't want to damage the shells trying to force them.

Sent from my X6pro using Tapatalk

Not sure that's going to help Hairy..... He should already have had the crank and cases together and torqued down to get the Plastigauge readings. Something is not right there? It may only be the natural spring in the shells pushing them back out when the casings are released. Use a very soft mallet and try gently tapping the edges down, don't use anything solid or you will pean over the shell edges.....The journals in the pictures don't look too bad although there is some evidence of pick-up. Unfortunately these cranks are not re-grindable as there's no oversize shells for them. You can however get the journals micro polished to help remove very minor damage. Never had it done myself but remember Rick Partington (Classic Bike mag) having his done when he featured the 400/4 rebuild. Somebody on here will know.

[simco1964]

Hi Roy,
           Can you not use a different coloured shell to reduce clearance? ie go from yellow to a green?
Simon

[royhall]

Not really. If you look at the sizes there is only a couple of thou between the largest and smallest. Thats just there to take up any manufacturing errors.

[simco1964]

What can I do to improve the amount of clearance?
I just don't have the experience as this is my first restoration project!!

Regards
Simon