Dave said, > " . . . its been a hoot, thirty and a half years and 1,501.1 hours of fun with a few minutes of terror thrown in."
Are you saying Dave that those heads and valves have 1501 hours on them? ************** Steve says to throw the valve train away at 250 hours? If done by Rimco - the place where he used to have his heads re-done - then by all means . . . throw it all away. They re-use old springs and valves (and probably the oil the engine came in the door with) and use what looks like must have been a meat grinder to cut new seats . . . so if Steve is talking about Rimco quality then what he said makes sense. Despite their lousy habits, the work Rimco did on my heads lasted about 475 hours before something failed. What failed were the re-used springs. It felt like a valve at the time with a lot of shaking and backfiring, but since was a long way from home when it happened I was glad to find out it was only an exhaust spring (#4). The engine continued to run near idle speed. In retrospect I realized I should have shut it down. The valves in the pictures at this link http://1drv.ms/1ePBdtF had at least 484 hours. Since Rimco re-uses anything they can get away with, I'm confident these valves had been re-ground at least once. Despite the erosion around the necks - the seats & faces were not leaking nor showing any indication they were headed that direction. I put new Manleys in simply because I had the heads off to replace the failed springs. It would have been dumb to have the heads off and not put new valves in, especially once I realized the the spring failures had been caused by Rimco re-using old parts. I didn't know shops cut corners like that. Once I understood they do, I realized I had to replace everything. The valves in Jim Faughn's engine came through that same shop. Time for VW fundi's out there to chime in with the TBO's they expect and have experienced with their 2180's. These two failures happening so closely together is causing a pretty bad impression re the VW. If Dave had 1500 hours on his engine then at least that failure becomes more understandable. As it is, what we've got in addition to these two recent failures is Steve's observation quoted by Mark, "He also said he'd only seen one other exhaust valve fail that caused catastrophic engine failure, and that was in Art Franks' Aerovee engine with 310 hours on it." And Mark's observation that "Although "sucking" an exhaust valve in high-time air-cooled Type 1 engines is not uncommon, I have never heard of this happening in VW powered aircraft." I haven't heard of it either, despite the fact many who fly behind a VW get their engine work done by (professional :-) buggy shops like Rimco. Nor have I EVER heard of a "spun bearing" on a VW, whether in an aircraft or normally driven and maintained bug. The common wisdom in my world is that the bottom ends of VW's run forever with reasonable care (by that I mean you put oil in them and don't exceed normal operating temperatures for extended periods). In an aircraft application, heads are looked at and cleaned out at 500 (if necessary) and given some new valves and springs at 1000 - not necessarily because they need it but just because it's inexpensive insurance. ************** Congratulations to both Dave and Mark for handling their emergencies so nicely. Mike KSEE ____________________________________________________________ America in 2017 Don???t let Warren Buffett???s warning continue to go unheard. Click here. http://thirdpartyoffers.juno.com/TGL3141/55c07f8fb28397f8f7b30st04vuc
