[Mgs] Fore and Aft Rod Movement

[Max Heim]

Hmm, the wrist pin has to have some endplay, and the rod bearing has some
tolerance, too, so I'm not surprised it has some movement with no rings
fitted. Add rings and a high-pressure oil film and everything tightens up, I
would imagine. Though I might think that 1600 miles would show "no" visible
wear...


--

Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the primer red one with chrome wires

on 10/16/09 5:04 PM, BDavis at bdavispics at yahoo.com wrote:

> I have a question about rod bearings on an MGB journal and would like some
> opinions, please.
> 
> Can there be 'any' lateral (forward - backward) rocking movement of a rod, up
> at the piston, when the piston is at TDC (no rings on the piston)?
> 
> Reason for the question: I can 'rock' the rod slightly in the bearing. I have
> some forward-backward movement at the top of the rod - not a lot but would
> have thought that the rod would not be allowed to do this.
> 
> These are 'new' Std. bearings (1,600 miles of use) on a new Std. crank and
> show normal wear. They were plastigaged at between 1 and 1.5 thou. between
> bearing and journals when installed. I have not plastigaged them again but as
> I say they show minimal wear for those few miles.
> 
> Thanks in advance for any information and opinions.
> Bill