Date: Sun, 13 Feb 2011 18:42:48 -0500
Reply-To: Joe Luther <jluther@ALFONS-HAAR.US>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Joe Luther <jluther@ALFONS-HAAR.US>
Subject: Re: General engine bolt/nut sizes
In-Reply-To: <33AC30861B2246B287BB33D994CF7D07@Mikelaptop1>
Content-Type: text/plain; charset="US-ASCII"
Thanks again for the reply. I have access to the 8.8 grade as well as 10.9
and 12.9, A2E coated and standard. I've worked with high speed metal
container manufacturing machines for 25 years, some US based and others
German made. When getting our US based equipment certified for the CE mark
back in the 90's TUV specified Nyloks because of the +/- 30% torque value of
conventional fastening components when surface texture and lubrication of
mating surfaces were considered. We also had to use 1/2" Lexan guarding for
ejection hazards in case the Nyloks weren't enough.
All this has stuck with me over the years and thinking about the VW engine
and the design just led me to wonder whether I could get better life out of
everything by considering some upgrades. Working for Germans for 12 years
has taught me that they usually don't underthink or underdesign things but
that is gradually changing, IMHO.
But, as I mentioned earlier, if you've had 30 years of good experiences from
straight torque then I'm overthinking this and it's one of the big reasons I
joined the list....you guys have done this and I haven't so I'm here to
listen and learn what has worked.
Joe
-----Original Message-----
From: Mike [mailto:mbucchino@charter.net]
Sent: Sunday, February 13, 2011 5:46 PM
To: Joe Luther; vanagon@GERRY.VANAGON.COM
Subject: Re: Re: General engine bolt/nut sizes
Fasteners are normally re-used as long as they're not corroded or stripped
in any way. I have seen some very old VW washers crack upon re-use due to
age-tempering/ work-hardening issues.
I only made the 'out-thinking' comment because it's so typical of so many
'rebuilders's of VW's, more often than not.
Yes, technology has advanced over the past few decades, but not too much
in the areas you're considering. I'm an FAA-licensed, fully-experienced
Airframe and Powerplant mechanic, and I can think of many improvements
possible in the VW designs, including the types of fasteners used.
Nylock nuts are not appropriate to high-temp applications like an engine.
Check the specs and you'll see that. Only High-temp (all metal) locknuts
are applicable there.
Do you have access to 8mm, grade 8.8, all-metal locknuts? If so, use
those, otherwise stock wavy washers and plain nuts are fine.
Aviation hardware would be best, but is very expensive. Some hi-po
builders use 'raceware' - http://www.raceware-fasteners.com/photo.htm)
Don't be nervous, the case edge bolts aren't under a lot of stress or
movement. The Type 4 main case tie-bolts are critical fasteners, but if you
look at them closely, you'll notice that they are very special,
application-specific bolts and washers, the Type 1 used studs there. The
type 4 is vastly improved and updated by VW engineers over the years, and
the Vanagon engine contains all of these improvements.
Mike B.
I'm really not looking at out-engineering or out-thinking VW but there is
newer technology in many areas since 1983 (such as the self locking nuts)
and I thought it good to ask the question whether others found it made sense
to use it here. I'm glad to hear you've had such good results relying on
straight torque for performance, in mission critical moving machine
applications I've always had to use Nylocs or other self locking hardware so
going by straight torque makes me a little nervous, I'll just have to get
over that.
Joe
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