Hi all im in need of a bit of help.I have a st170 which has spun number 4 big end bearing due to lack of servicing/oil starvation.The bearing journal spec is between 46.89mm-46.91mm for standard size which 1,2,3 are all in spec and i have replaced the bearings with standard size.As for number 4 the bearing journal measures 46.35mm so i need oversize bearings but which size .25,.50,or .75 as i cant find any more info for this engine for oversize bearings and just want to repair it to sell so dont want to go down the regrind route or remove the crank for any reason.The bearing clearance is 0.016mm-0.070mm if anyone could shed a little light that would be great many thanks.

 

can you post up some pics of the car so our members know what it looks like so they can avoid it
The reg number would be appreciated too

 

I suspect you think im doing a bad thing when i want to bring it back from the dead and repair it.The bearing journal has no ovality and looks almost polished not scored or damaged just worn hence oversize bearings needed.The car itself has 1 owner from new and 54k on the clock and is too good to break.I brought it form a work friend who has no mechanical knowledge and just wanted rid.

 

i think the fack its going to get 1 pair of big end shells only is the worry, this is not good

used perfect cranks/rods for these engines are ten a penny that will take a full set of shells and be perfect again

EDIT***And "repairing it to sell it" is just the icing on the cake, nobody should be subject to a bodge like that

 

Cylinders 1,2,3, have all been treated to nice fresh new bearings but just stuck with number 4 as to which size.

 

Anyone else have any ideas?