We had our two Volvo Penta 71B engines this past winter sent out to be re-built. After the re-build and re-installation on our tour boat, we now find they are now each using a litre of oil, after a days operation. What could have been done or not done in the re-build to create this new issue with the Volvo Penta's? SVMO Stan

Oil scraper rings installed upside down, they'll scrape oil off the cylinder walls, upward toward the combustion chamber, instead of down to the crankcase. Happened to me on a genny "rebuilt" by a Russian "Chief" I relieved and his Russian 4th. He "saved money" by reusing the piston rings, turning them upside down so they'd wear the other way. (?????)

the question is, who overhauled it?

Were the liners de-glazed (Honed)? if they didn't do that, but fitted new rings the engines will drink oil. The new piston rings will never wear in to make an oil and gas tight seal against the liner, just skid over the top of the glassy glaze.
If they are using that much oil, then I would have thought that you would have a legal case against the people who did the work. The overhaul was not done to an acceptable standard, and they should either pay for it to be done properly by competent Engineers or do it themselves properly, ( if you trust them with your engines a second time)

B.P.

He "saved money" by reusing the piston rings, turning them upside down so they'd wear the other way.

Points for creativeness if nothing else.
Ive been leaning toward a customer service model while at work, and knowing what your customer want is central to that. In this case the "Chief" knows what the company wants, at least in the short term.

Fantastic story.