Im currently rebuilding my engine as you may have seen on my previous postings. I have a few questions. Firstly the cam shaft when in position with it retaining plate in place it can be pushed and pulled by approx 3-4mm, is this normal. Secondly ive examined the main bearings and on the shells some of the copper layer is starting to come through. Do i need a crank regrind? There is no scoring marks on any of the surfaces and all looks quite good for 90000 miles. Can i just put a standard set of shells on and have happy motoring for another 20-30 thousand miles. There were no oil pressure problems, so is all good??
The shells certainly need renewing - best really to check the crank with a micrometer - but if there is no scoring then it's likely it will be ok. I advise you to fit a new oil pump while you are in there. The camshaft will not float like that when the cam drive pulley is in place and the nut tightened up. This is your chance to upgrade the engine a bit by fitting a different camshaft - the MG Metro cam is the best ever fitted as standard to an A series engine - if you get one you will also need a spade drive oil pump. It makes a huge difference to the engine. You don't say engine capacity - if it's a 948 seriously consider fitting the camshaft from a 1098 (AEG 630) it has slightly better timing and more valve lift. In fact if you also fit the cylinder head from a 1098 (needs 60 thou skimming off first) then it is possible to get just as much power from the 948 - although it does have to rev 10% more to get there !
There is a triangular plate held by 3 bolts, this locks the cam in. Some clearance can be reduced by renewing this plate as it tends to wear, it has a similar surface on one side to the bearing shells, so don't be tempted to turn it round!
