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...
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 !
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 !
