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RE: Head bolt re-torquing



And 90 + 90 degrees is very easy to identify on a hex bolt since corner
to corner is 60 degrees.  When I installed the new and improved head
gaskets on my '96 RS I just used a sharpie to mark the 90 and 180
positions.  I was careful to do this as precisely as possible and was
probably accurate within a couple of degrees.  20,000 miles later and no
problems indicates this procedure is adequately accurate.


- -----Original Message-----
From: owner-oilheads@xxxxxxxxx [mailto:owner-oilheads@xxxxxxxxx] On
Behalf Of Bob Hadden
Sent: Friday, April 08, 2005 7:35 AM
To: oilheads@xxxxxxxxx
Subject: Re: Head bolt re-torquing


Ben,  This method of torque spec is common now.  They are using a 
specific bolt on the head, which means that you would not want to use 
any substitute bolts on this application.  The 90 degree figure (or 
whatever it is) is set to provide a specific bolt stretch, thus 
applying a specific pressure to the gasket area.  This is more accurate 
than providing a twisting torque number, which contains a lot of 
variables (lubrication, thread condition etc.).  You want to look at 
the ibmwr site, or a service manual for the torque procedure on your 
bike.

Bob Hadden '05R12GS, '62R27


On Apr 8, 2005, at 10:06 AM, Ben Barkow wrote:

> On previous boxers, conscientious attentions to the head bolts and
> cylinder
> studs were important. Not so on the Oilheads where after the 600 mile 
> check,
> nothing but neglect to the whole dozen of them - except for loosening 
> two
> studs for valve sideplay adjustment.
>
> I'd appreciate any information on re-torquing or the avoidance of
> same. It
> seems there's a 90 plus 90 degree spec on the cylinder studs (must 
> make them
> pretty tight, eh?). Is that the way to do it or could a max torque 
> rating be
> used?
>
> Cheers.
>
> Ben
> --
> Ben Barkow, Toronto... 39 seasons on Beemers, 44 as a biker
> 1999 R1100S, 2004- Leo Vince exh, JetHot coatings, Techlusion 1031,
>   K&N filter, Ben's windscreen

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