948cc Piston Bearings

Post by **MacQuigley** » Wed Mar 18, 2009 2:42 pm

Can anyone tell me the crank diameter for the piston bearings, as it should be.

My Haynes manual shows the main jourals as being 1.75" in diameter but doesnt tell me what the piston diameter should be.

I want to order new shells but dont know whether standard will be OK or if I need to go +0.010 or more (though as the main journals measure 1.749-1.75, Id susspect I'll be OK with standard shells for the piston big ends).

Post by **bmcecosse** » Wed Mar 18, 2009 10:27 pm

The big-ends on the crankshaft (not 'piston bearings' - but I know what you mean) are 1.625" diameter as standard - on the 948 and 1098 engines. If you look at the back of the old shells - they will be marked .010 or .020 etc if they are oversize - to suit undersize crankshaft journals. Check on ebay for shells - I bought some v cheaply recently. If the engine is out of the car you should v seriously consider fitting a new oil pump along with the new shells. And of course - if the journals are scored (or worn oval) the crankshaft needs a regrind - and then you will need oversize shells.

Post by **MacQuigley** » Wed Mar 18, 2009 10:40 pm

I was out in the garage, applying yet more filler to my door repairs (full lower repair to both doors. Just trying to get the final shap to the edge of the "bulge) and as I walked by the shelve I spotted sopmething out the corner of my eye - my original workshop manual! DOH!!!

Checked the sizes listed there (think it list the big ends as crakpins) and it told me the same. So I remeasured my crank and the worst of the 4 is only 2thou out. So standard shells will be find (no ware at all on the crank, main journals are only 1thou out).

So I now need to list all the parts I need and a new oil pump is going to be in that list. Seems daft now the engine is stripped not to change it. It would be a big job to take it all back out again.

Anyway the lesson for tonight is remember you have a workshop manual and consult it - but many thanks for the reply.

I will check Ebay. Normally I buy from Bull Motif, but Ive been using Ebay more and more for parts for the 2 old Landy's, so I'll give it a try.

Post by **bmcecosse** » Wed Mar 18, 2009 10:48 pm

I have sent you the download for a copy of the last Leyland Workshop Manual. I recently got a set of new-old-stock BMC big ends (in fact I may have made them when I worked at Glacier in Kilmarnock - they are certainly Kilmarnock bearings!!) for £3 from ebay! And a set of mains ( original Leyland stock ) for a 1275 were only £10 - fom Slovania !