Morris Minor Owners Club

I have just stripped down my marina engine that's peeing oil at a rate of knots and found out why... the top rings on three pistons are broken and the scroll seal gasket was incomplete!

anyhow I wants to take bits to the machine shop to get them sorted tomorrow and theres one thing I want to check

The main bearings have a dia of 1.991 inches which I assume is 10 thou undersize but it was running on standard size bearings.... the big ends were 1.740 inches dia and running on 1P thou undersize bearing which I assume is correct...

so what main bearings do I want?

It would seem you need 10 thou oversize bearings (to suit the undersize crank) - provided the crank is not worn ? Amazing it was running on std bearings - with u/size crank ?? The oil pressure must have been terrible !

oil pressure was rather high! I'm going to get the machine shop to check them...

Hard to see why it would be high - it would be flooding out the main bearings - and very little getting to the big-ends. The rumbling must have been amazing. Maybe the crankshaft is just worn now !

No rumbling, engine sounded absolutely fine, just lacking in power and peeing oil...

Can't see how if the shells really were 10 thou undersize!