Big End Bearing Replacement

[vfrman]

I can't see the pic (it's blocked from me whilst at work), but to answer the question...yes. You need to remove the clutch to see the code. But that isn't a big deal, because this must happen to split the cases anyways. You also must remove the flywheel and genny wiring, because it is bolted to both halves of the cases.

[hunter]

Can't open the link.
The numbers are acually behind the primary gear on end of crank.

[dobbslc]

The bearings are supplied with pressurized oil from the pump NOT by being dipped in oil in the sump. Being lent over on a long bend won't deprive only one bearing, if the oil was that low it means the pick up pipe was exposed to air and you will have starved the whole engine of oil!
If you've done a big end bearing you need to check everything or you risk wasting time and money when it goes pop later on if you've missed the other worn out parts.
Check the crank journals for any marks if they are ok you are lucky, then you need to measure the clearances with plastigauge and replace the bearings to suit and not necessarily back to the old bearing sizes. Big ends and main bearings will need checking. Big job and it will cost you a fair bit. Check everything before you spend any cash!

[VtypeV4]

I can't see the pic either..

Did your oil light come on? does it work?

Does your engine knock?

[lukemillar]

Check the crank journals for any marks if they are ok you are lucky, then you need to measure the clearances with plastigauge and replace the bearings to suit and not necessarily back to the old bearing sizes.

This is very good advice. I have rebuilt engines that haven't spun any bearings or would even be considered 'high mileage' and they have required a different colour code to that which the book specifies

[tevie54]

I changed the crankshaft on my NC when it ran a main bearing, I just used the big ends and mains that came with the new crank,I split the cases without disturbing the heads and just lifted out the old crank with the old bearings and simply swapped everything over. The number of people that told me you cant do that because they're all matched ,well four years and several trackdays with 14.000rpm down Cadwells back straight later it was still going strong so I wouldn't worry too much about colour coding, don't forget they were just mass produced on a production line.
Incidently it's only the top end that is fed under pressure, the bottom end is splash fed by the oil in the sump.

[VtypeV4]

Incidently it's only the top end that is fed under pressure, the bottom end is splash fed by the oil in the sump.

That seems unlikely..

If it was a rolller bearing crank it may be (only just) plausable but not with shells, they die without a pressure feed.

[hunter]

I think you have been more than lucky mate,
And the crank is pressure fed as are all engines,
Splash fed it wouldn't last 2 mins.

[Neosophist]

I changed the crankshaft on my NC when it ran a main bearing, I just used the big ends and mains that came with the new crank,I split the cases without disturbing the heads and just lifted out the old crank with the old bearings and simply swapped everything over. The number of people that told me you cant do that because they're all matched ,well four years and several trackdays with 14.000rpm down Cadwells back straight later it was still going strong so I wouldn't worry too much about colour coding, don't forget they were just mass produced on a production line.
Incidently it's only the top end that is fed under pressure, the bottom end is splash fed by the oil in the sump.

this is possibly the worst information I've ever read from a first time poster. probably the worst information this year too.

Why do you think so many people told you they are matched, and the service book itself tells you how to use plasti-gauge to measure the super fine tolerances of the bearing shells?

Yes the bearing shells are mass produced, in a range of sizes.

There are of course service tolerances and you seem to have been very lucky in that your engine appears to be within specification but myself and no doubt others on here / others that gave you advice have seen engines ruined by incorrect bearing shells being installed during a rebuild.

Your advice seems to be solely based on one lucky engine rebuild that hasn't died even though you didn't check the clearances on the bearings.

This is no different from winning one game of Russian roulette and proclaiming to everybody else that the game is completely safe.

To the op, you may get lucky and be able to assemble it within a safe tolerance but for the sake of some cheap plasti-gauge do the job properly and measure things up. if you are not as lucky as the above poster you'll do more damage to the block and have to take it apart again!

Also your advice about the oil feed to the bottom end is completely wrong too. It's fed from the oil pump. If it were splash fed there would be splashers / flingers. And since this isn't a side-valve lawn mower I doubt splashfeed would supply enough oil to prevent catastrophic failure

[Variablevalves suck]

The idea of the shell bearing being made in different sizes is because this sets the oil clearance that you should measure.
Oil is then pumped into/ through this clearance and the crank runs on this carpet of oil, not on the journal its self, if this goes belly up and the crank runs on the journal it will pick up very quickly and seize.