Mark said, " . . . I couldn't help but wonder what mechanic bozo would do a "valve job" and not even bother to blue it and lap the valve, which would have graphically shown the total lack of seal between valve and seat." That honor belongs to the outfit below. RIMCO once had a good name in the VW world and in some minds may yet still, but in my personal experience they are butchers of the worst kind. Steve used to send his heads for rebuild to these clowns. They are the ones that, in addition to whatever other rebuilding sins they commit, are in the practice of re-using valve springs. This caused a forced landing in Venice, Florida in my case. I was over 11K feet high when this occurred so this incident was no more than a couple day delay in my trip but when it happened I was afraid it was a valve. It was a relief to find it was only a broken spring . . . one of two. I rebuilt my heads once I arrived home and found Mark's Corvair documentation to be of huge help. Since good engine work is pretty important . . . especially when we are up in the air (smiley face) . . . I share the concept of doing the work myself. Most VW shops deal with dune buggies where operators expect to re-do their engines after every season. This expectation extends to the mechanics that re-do the engines. With the expertise contained at Mark's Corvair link below, there's little excuse to not do our own engines.
This is the outfit that Steve used to send his heads to. They're still in business. Somehow. https://fatperformance-rimco.com/ MikeKSEE ***************************************** On Thursday, November 3, 2022 at 07:02:12 AM PDT, Mark Langford <m...@n56ml.com> wrote: Jeff York wrote: >>Wanted some advice on my cylinders. I pulled my heads on my ĢPAS 2180 VW to >>have them done. Had one cylinder that seems low on compression and needed to >>help coil one so why not have them rebuilt. Lots of carbon on the heads and a >>few of the cylinders give me the impression the cylinders have been over >>washed from running too rich. << I think it boils down to what's more important to you, your time or your money? And maybe also, how much of a hurry are you in? I'm not sure what you mean by "washed over" or "coil one", but those cylinders are reusable, and when the engine's turning 3000 RPM, those scratches will not be a factor. But ersonally, if I have the heads off of a VW or Corvair, I either hone the cylinders and re-ring them, or more usually, simply replace them, as cheap as VW cylinders are. And I wouldn't trust anybody to do a valve job on a VW (or anything else). I've told this story before on my web page, but I'll tell it again. I first met Jim Hill at a KR Gathering, and found he was from my local area. I visited him at his hangar, where he complained that it took forever for his "rings to seat" in his KR2. It seems his 2180 ran like a 3.5 cylinder for the first 50 hours, then smoothed out, but at 100 hours it became a 3 cylinder. He went thru this 3 times, each time getting a "valve job" from a reputable engine builder, GPASC. I insisted he let me look at his heads before he sent them off again. First thing I noticed was that one valve had a lot of slop, with the seat quite eroded valve guide wallowed out, so I knocked out the guide, and went to the freezer and got a new valve guide to drive in it's place (yes, I keep a box of VW guides in my freezer at all times). When I started grinding the seat, the stone only ground one side, sort of crescent shaped like my example above! Hmmm. It became obvious that the valve guide was not coaxial with the seat when the head was manufactured. I ground the crap out of it until it sealed, but I couldn't help but wonder what mechanic bozo would do a "valve job" and not even bother to blue it and lap the valve, which would have graphically shown the total lack of seal between valve and seat. What was happening was the valve wouldn't seal, but the side forces on the valve would eventually elongate the bore in the guide until it did seat, and it would start running better, usually after about 50 hours. But then that slop in the seat would allow it to wobble around and wear the valve face and seat excessively until it needed another valve job at 100 hours. Happened three times, just like clock work. This was the first time I'd ever seen this phenomenon on a head straight from the factory, but somebody else had THREE opportunities to notice it before I did. This is just one of the many reasons nobody touches any of my cars but me, but don't get me started on the subject of paying "professionals" to do something for you! The mind-blowing thing about this is that GPASC would simply replace valve and guide and not re cut the seat, and send the head back to him for a repeat performance. I visited Steve's house when I bought N891JF, and his basement shop was pretty basic. I got the impression that he farmed out all the engine rebuild work to some local place....at least that's what I'd like to think. Whoever did that work either had no conscience, or no clue how to properly rebuild a head. I don't trust any part of my engine to anybody else, and no, I'm not "open for business" to rebuild heads. Heads are pretty cheap too, in the grand scheme of things, but I do use top notch exhaust valves, for a good reason. Wide open airplane usage is hell on them. A sucked valve will kill an engine in less than a second. Been there, done that at 7500', got lucky and didn't do much damage to the plane in the corn field landing. As Mike Stirewalt mentioned, see some of the many Corvair engine rebuilds I've done on the Corvair (which are VERY similar to VW's), and on most of my engines, I run VW pistons and cylinders. See http://www.n56ml.com/corvair/valvejob.html for a LOT more on this subject. I could go on forever about this kind of stuff, but I'll spare you and quit here..... Mark Langford m...@n56ml.com http://www.n56ml.com Huntsville, AL -- KRnet mailing list KRnet@list.krnet.org https://list.krnet.org/mailman/listinfo/krnet
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