

| Subject: | Re: 2.1 rebuild - new nuts for case halves-thoughts for all bolted connections. |
| From: | Tom Lambas |
| Date: | Tue, 10 May 2011 21:23:05 -0500 |
Thanks Dennis, I have all my old case nuts, washers, and through-bolts soaking in naptha, I ordered a bag of type 1 case assembly hardware also. At the very least, I'll be able to use the 4 nice sealing nuts for the oil pump, and hopefully end up using mostly new hardware. BTW, I used almost all of your seat belt stuff. I was surprised at how worn all the seat belts were in my van. Cheers, Tom in Minneapolis On Mon, May 9, 2011 at 10:41 PM, Dennis Haynes <d23haynes57@hotmail.com>wrote: > Here are two links that give some good information. One is how a clamped or > bolted connection works and is indicative of case main bearing bolts and > rod > bolts. The other is the relative strengths of various grades of fasteners. > Note the difference in strength of the A2 or A4 stainless as compared to > property class 10.9. This class is the most common class used on the > Vanagon. The real important stuff can be 12.9. In order for these bolted > connections to work the nut and if used washers need to be matched. The nut > has to be strong enough to stretch the bolt and get it under tension. The > washer has to carry that load. If the washer distorts then the connection > becomes loose. > > In addition to the strength of the material, finish, (zinc, black oxide, > chrome, cadmium, organics) and lubrication, (oil, anti-seize, sealants, > Loctite) will affect the torque required to reach a given clamp load. Black > oxide, organics, and cadmium are often used on high strength fasteners as > they provide more consistent torque tensioning. Zinc is sometimes an issue > as it may cause hydrogen embrittlement. Some lubricants or wax coatings can > reduce required torque by 40% or more. Consider that when thinking of never > seize on your lug bolts. > > Many engine problems or failures come down to fluid problems or fastener > failures. Internal head leaks, (gasses in coolant or coolant in cylinder) > if not due to an actual cracked head are really a fastener failure. A > problem is that engines will often be repaired or rebuilt without > addressing > the failed part. > > Dennis > > > http://www.unified-eng.com/scitech/bolt/clamping.html > > http://www.tessco.com/yts/customerservice/techsupport/whitepapers/pdf/bolt_g > rade.pdf > > > > -----Original Message----- > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of > Daniel Rotblatt > Sent: Thursday, May 05, 2011 12:05 PM > To: vanagon@GERRY.VANAGON.COM > Subject: Re: 2.1 rebuild - new nuts for case halves > > There have been several discussions on other forums about this. > Essentially, if it's a torqued nut then the torque setting is defined by > the > type of nut and stud - stainless (or different grade nuts for that matter) > require different to torque settings. Saying "stainless is not as strong" > is incorrect - like different grades of nuts, it depends on the alloy of > the > stainless. I imagine that standard stainless nuts may be "less strong" > then > standard non-stainless nuts, but that is still a generalization. The > alloys > used in stainlesss (and there are many many alloys) give the metal > different > properties then carbon steel. There is even a problem changing the > strength > class (using grade 8 nuts/bolts when grade 5 are specified) - some > nuts/bolts are specified because they are supposed to fail at a certain > stress to prevent further damage to the engine - and of course there's that > torque issue again. > > The upshot, is that if it's a torqued nut, use the manufacturer specified > if > possible. If you replace with stainless when not specified, you take a > chance that the nut will fail. Doesn't mean it will, just that it may or > may not be within proper specifications (thus Franks observation that he > uses stainless hardware and does not have failure). > > Dan > Los Angeles, CA > '85 Westy Weekender > > On May 5, 2011, at 2:33 AM, Frank Condelli wrote: > > > I beg to disagree. All engines I have rebuilt here get > > stainless hardware everywhere possible. Never seen any problems > > related to the use of stainless hardware on the engine cases or > > elsewhere. See here > http://www.frankcondelli.com/21engpcs.htm > > > > > > On 2011-05-05, at 12:00 AM, Automatic digest processor wrote: > > > >> I sure would not be putting any stainless fasteners on it. > >> they are not as strong .. > >> stainless is not titanium or 'fautless' like people want to think it > >> is. > > > > > > > > Cheers, > > > > Frank Condelli > > Almonte, Ontario, Canada > > '87 Westy & Lionel Trains (Collection for sale) Frank Condelli & > > Associates - Vanagon/Vanagon Westfalia Service in the Ottawa Valley > > Vanagon Stainless Steel Exhaust Systems BusFusion a VW Camper camping > > event, Almonte, ON, June 09 ~ 12, 2011 >
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