Almost all the mass rebuilders are working with cores that were known to be non-re-buildable by just changing parts. The cores they get have been overheated or with such high mileage that the cases require a lot of machine work and the head repairs include welding. Add to this the lack of quality piston-cylinder sets and many rebuilds are just disappointing. Common issues with some rebuilds include low oil pressure, bad rings, low compression due to incorrect piston design, and early valve failures. You would do better to get a premium engine or a custom rebuild. You want really good or new heads and you want to know where the piston-cylinder set came from. You want a warranty that also includes some compensation for labor. If having a shop install it let them source it and warranty the complete job. I've seen many a motor get messed up due to installation-start up issues. The lack of good cases at this point is a primary driver for engine conversions. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of jed batchelder
Sent: Thursday, August 3, 2017 8:41 PM
To: vanagon@GERRY.VANAGON.COM
Subject: engine rebuild

has anyone bought the rebuilt engine from the bus depot?  is it a good one and worth the money?