what is in the case....

[bullit]

on my 90SE

latterly what is the (crank) case

I've cleaned up the engine , inside and outside, 

the engine is empty, re-joined  the crankcase halves, and measured....

 the main bearing OD bore diameter, normally it must be 67.704 to 67.715

I measured up/down  lets say 67.74 to 67.75,mm 

that is no problem, new bearings , 010 undersize, and we can calculate  the crankshaft grinding size

but  measured left/right I've got  67.78 and 67.60 mm

well the oversize  67.80 is no problem  , side play left/right is normally more than std

and that is regulated by the bearing ( the bearing hole must be equal round) but it is no problem when it is  a

bit out off the diameter.(left/right)

I am a lot more concerned about the 67.60mm, that is more than the bearing oil clearance

even when i remove the locating dowels, and put  steel rings (67.70mm) into the main bearings holes,(both ends) 

still I have got more than 0.06 mm out off roundness main bearing holes...

to much i think

is that becomes after 250.000 km  of good use?
well I suppose I have to skim the lower bearing case, and  line honing the hole crankcase.....
wow what a tech talk........ 

greetings  sietse // holland  ( not mentioned my langauge)

Edited October 15, 2014 by bullit