G60 crank measurements/ conrod bearings & nuts?

[bristolbaron 10]

Technical one above my head i'm afraid..

 

Conrod bearings need replacing in a G60, mechanic is asking for 'standard' diameter & tolerence of crank where it's covered by the bearing? Possibly something someone with a Bentley manual would know?

There are different size bearings listed - 'standard' +.25, +.50, +.75

I'm guessing the thicker ones are for worn cranks? But without crank or bearing diameters how the hell do I know if I don't need standard ones?

 

Next Q.. Been reading a bit about the bolts being 'two use' stretch bolts. Gonna replace them anyway and have found a source for them. But the nuts are obsolete and seem difficult to find. Can they be reused? Otherwise, it's off to classic parts at £5 a nut and a lengthy wait.

 

Hopefully I've given someone enough info to go on!

 

Cheers

 

Baz

[VEEDUBBED 0]

You can reuse the Nuts no problem. As far as the crank Goes, just measure the big ends with a micrometer or get an engineering firm to do it. Don't try oversize bearings on a standard crank as the engine will lock up. Obvious maybe but you never know..

Can I ask why the bearings have to be changed? Is the crank damaged or are the journals scored? Did the engine show any signs of the classic 'Big end knock'?

Whilst your in the engine I'd check the small end bearings too..

I'd tell the mechanic to use Plastigauge on the crank regardless, that way he'd be 100% sure on the bearings required.

Standard practice anyway when rebuilding.

Edited February 18, 2017 by VEEDUBBED

[SR_Neale 10]

Where are you getting the stretch bolts from? Have taken the head off my G60 for a re build so will be needing some myself. Cheers

[bristolbaron 10]

You can reuse the Nuts no problem. As far as the crank Goes, just measure the big ends with a micrometer or get an engineering firm to do it. Don't try oversize bearings on a standard crank as the engine will lock up. Obvious maybe but you never know..

Can I ask why the bearings have to be changed? Is the crank damaged or are the journals scored? Did the engine show any signs of the classic 'Big end knock'?

Whilst your in the engine I'd check the small end bearings too..

I'd tell the mechanic to use Plastigauge on the crank regardless, that way he'd be 100% sure on the bearings required.

Standard practice anyway when rebuilding.

 

One bearing is very worn, and engine clattering - big end knock I guess. It doesn't sound healthy on idle and horrendous at 2k revs. Currently just have sump off, so no access to small end bearings etc. It looks like we've found the problem so will go with big end, if that doesn't solve it, it'd be engine out for full overhaul.

 

Where are you getting the stretch bolts from? Have taken the head off my G60 for a re build so will be needing some myself. Cheers

 

stretch bolts are for con rods, probably no use to you but I sourced them from 'micksgarage' febi bilstein 02124.

I've bought the nuts from heritage. Couldn't do half a job of half a job!

[SR_Neale 10]

Just been on the web site and can see me spending alot of money.

[dragon green 4]

Get the engine stripped and all the reciprocating parts down to BassetDown balancing(only down the road from you)Andy there really knows his stuff

 

 

Sent from my iPhone using Tapatalk

[bristolbaron 10]

Get the engine stripped and all the reciprocating parts down to BassetDown balancing(only down the road from you)Andy there really knows his stuff

 

 

Sent from my iPhone using Tapatalk

 

Hmm.. that gets me into the realms of spending copious amounts of money! Good to fall back on though cheers!

[VEEDUBBED 0]

Your quite right baz, no sense in spending loads of wonga on a clapped out g60 mill mate.

Sooo your gonna buy my forged 9A valver bottom end and then turn it into a nice g60-16v car..

And yes VEEDUBBED does have all the bits..