Author Topic: New Main and Big End Bearing Shells  (Read 4103 times)

Offline adriangsmith

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Re: New Main and Big End Bearing Shells
« Reply #15 on: May 23, 2016, 07:43:34 PM »
Thanks all,
No pits on the crank shaft just the faint score lines.
I'll give it a wipe over and take some more shots.
Big thanks for the service bullitins Ash, very informative.
Adrian
Triumph Thruxton 2004
Honda CB750F1 1976
Honda CB400F   1976 (current project)

Offline adriangsmith

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Re: New Main and Big End Bearing Shells
« Reply #16 on: May 23, 2016, 08:09:19 PM »
cleaned and checked. no obvious ridges on the mains but they feel a little rougher than i would expect.
Also included an image of the old main shells, all of them worn pretty much the same as these.
Triumph Thruxton 2004
Honda CB750F1 1976
Honda CB400F   1976 (current project)

Offline adriangsmith

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Re: New Main and Big End Bearing Shells
« Reply #17 on: May 24, 2016, 06:10:25 AM »
The cam journals are what caused me to strip the engine again.
It suffered a top end oil feed failure due to a grain of sand stuck in one of the metering jets!
Found a new cam tower, just need to find a camshaft now as the right hand end is chewed up beyond repair.
Oil pump is on my list for a strip and rebuild.
Must admit the engine seems to have had a hard life and lack of maintenance.
When i bought the bike it had not been on the road since 1986.
I did a top end rebuild to replace the cam chain and tensioners, tensioner wheel was completely worn away, blade guide slots in cases worn as well.
So here i am again doing the job properly with a full rebuild.
Black shells readily available from DSS and strangely enough are cheaper than the others. but will probably follow your suggestion and go for a set of browns.
Thank you all for your help and advise.
Triumph Thruxton 2004
Honda CB750F1 1976
Honda CB400F   1976 (current project)

Offline royhall

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Re: New Main and Big End Bearing Shells
« Reply #18 on: May 24, 2016, 07:08:30 AM »
Whilst there's no facility for regrinds you can have the journals micro polished. Not sure who does it, but Rick Partington of Classic Bike had the 400 he was building done. May not need it though.
« Last Edit: May 24, 2016, 07:44:41 AM by royhall »
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Offline hairygit

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Re: New Main and Big End Bearing Shells
« Reply #19 on: May 24, 2016, 07:47:49 AM »
Before completely giving up on the can, give S.E.P. in Kegworth a call. I gave seen them repair cranks that look like ploughed fields by submerged argon arc welding the journals, then grinding back to original spec, and the crank is then good for many years to come. Chances are the journals on your cam may respond to the same treatment, and may prove easier and cheaper than trying to source a replacement.

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Offline AshimotoK0

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Re: New Main and Big End Bearing Shells
« Reply #20 on: May 24, 2016, 08:58:42 AM »
Whilst there's no facility for regrinds you can have the journals micro polished. Not sure who does it, but Rick Partington of Classic Bike had the 400 he was building done. May not need it though.

I do have a spare  (bare)  crank that I got miked up by my 'miking' expert and the journals were all  good. Sadly he passed away last summer, very suddenly. Think it 'owes me the 'ubiquitous' 25 quid (it was off a K7 but all cranks basically the same, up to the auto), but your crank is probably recoverable anyway by the sounds of it .  Yes that article by Rick Partington in CB was interesting .. the kind of article they should be doing rather than one I read on bead blasting ..where, at the end,  they basically told you in CMM to give it to the experts (and pay an enormous amount of money). That mag went sadly downhill when Rod Gibson passed away :'(

BOT are you guidance on this, IMHO (Bryan, Oddjob Trigger  ;D ;D ;D ;D)
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline ginger_jim

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Re: New Main and Big End Bearing Shells
« Reply #21 on: May 24, 2016, 09:08:06 AM »
Before completely giving up on the can, give S.E.P. in Kegworth a call. I gave seen them repair cranks that look like ploughed fields by submerged argon arc welding the journals, then grinding back to original spec, and the crank is then good for many years to come. Chances are the journals on your cam may respond to the same treatment, and may prove easier and cheaper than trying to source a replacement.

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+1 sending to SEP, they will provide the shells too.

Offline AshimotoK0

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Re: New Main and Big End Bearing Shells
« Reply #22 on: May 24, 2016, 12:44:37 PM »
Bryan, Oddjob Trigger
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline royhall

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Re: New Main and Big End Bearing Shells
« Reply #23 on: May 24, 2016, 03:24:44 PM »
Whilst there's no facility for regrinds you can have the journals micro polished. Not sure who does it, but Rick Partington of Classic Bike had the 400 he was building done. May not need it though.

I do have a spare  (bare)  crank that I got miked up by my 'miking' expert and the journals were all  good. Sadly he passed away last summer, very suddenly. Think it 'owes me the 'ubiquitous' 25 quid (it was off a K7 but all cranks basically the same, up to the auto), but your crank is probably recoverable anyway by the sounds of it .  Yes that article by Rick Partington in CB was interesting .. the kind of article they should be doing rather than one I read on bead blasting ..where, at the end,  they basically told you in CMM to give it to the experts (and pay an enormous amount of money). That mag went sadly downhill when Rod Gibson passed away :'(

BOT are you guidance on this, IMHO (Bryan, Oddjob Trigger  ;D ;D ;D ;D )
I do believe the F2 crank is different?
Current bikes:
TriBsa CCM 350 Twin
Honda CB350F in Candy Bacchus Olive
Honda CB750F2 in Candy Apple Red
Triumph Trident 660 in Black/White
Triumph T100C
Suzuki GS1000HC
Honda CB450K0 Black Bomber
Honda CB750K5 in Planet Blue Metallic (Current Project)

Offline AshimotoK0

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Re: New Main and Big End Bearing Shells
« Reply #24 on: May 24, 2016, 04:29:50 PM »
[ Guests cannot view attachments ]
Whilst there's no facility for regrinds you can have the journals micro polished. Not sure who does it, but Rick Partington of Classic Bike had the 400 he was building done. May not need it though.

I do have a spare  (bare)  crank that I got miked up by my 'miking' expert and the journals were all  good. Sadly he passed away last summer, very suddenly. Think it 'owes me the 'ubiquitous' 25 quid (it was off a K7 but all cranks basically the same, up to the auto), but your crank is probably recoverable anyway by the sounds of it .  Yes that article by Rick Partington in CB was interesting .. the kind of article they should be doing rather than one I read on bead blasting ..where, at the end,  they basically told you in CMM to give it to the experts (and pay an enormous amount of money). That mag went sadly downhill when Rod Gibson passed away :'(

BOT are you guidance on this, IMHO (Bryan, Oddjob Trigger  ;D ;D ;D ;D )
I do believe the F2 crank is different?

[ Guests cannot view attachments ]
« Last Edit: May 24, 2016, 04:34:44 PM by AshimotoK0 »
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline royhall

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Re: New Main and Big End Bearing Shells
« Reply #25 on: May 24, 2016, 06:34:10 PM »
O Bugger wrong again. Cheers Ash.
Current bikes:
TriBsa CCM 350 Twin
Honda CB350F in Candy Bacchus Olive
Honda CB750F2 in Candy Apple Red
Triumph Trident 660 in Black/White
Triumph T100C
Suzuki GS1000HC
Honda CB450K0 Black Bomber
Honda CB750K5 in Planet Blue Metallic (Current Project)

Offline Trigger

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Re: New Main and Big End Bearing Shells
« Reply #26 on: May 24, 2016, 08:51:09 PM »
Don't believe part numbers when it comes to cranks  ;)

 

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