That is true about loosining the bolt to retorque. Make a note of what
position the torque wrench is in before you loosen the bolt, then when you
tighten the bolt to the specified Setting see if it is in the same place.
Also lube the bolt threads with oil. It will move easier without giving you
a false reading or pulling the threads out. Pat
-----Original Message-----
From: Marc Sayer <marcsayer@home.com>
To: datsun-roadsters@autox.team.net <datsun-roadsters@autox.team.net>
Date: Thursday, March 22, 2001 9:32 PM
Subject: Re: 2L Head gasket
>"Patrick P. Castronovo" wrote:
>
>> 2- Torque the head in the right sequence.
>> 3- Torque in three stages. First, put all the bolts in down to the head
to
>> just touching the head. Then moving the bolts 1/4 turn on each of them
in
>> sequence with just finger pressure on the ratchet, going around until you
>> can no longer use finger pressure, then Torque all the bolts 45 lbs.-
then
>> 55 lbs. - then final 65. lbs It is VERY Important that you compress the
>> metal gasket around each cylinder slowly and evenly. Then after 500
miles
>> of driving, retorque to 65 again. Then again after 500 miles, if the
Torque
>> Wrench moves tightening it more, then try again after another 500 miles.
>> Chances are that you will not have to do it a third time, but check it
>> anyway.
>> Then do not forget to use Distilled Water in the radiator, with a 50%
>> solution of a good Antifreeze(Prestone)
>> Do not run the engine with Just water, as the Anti freeze Lubricates the
>> Water Pump. Then, Good Luck also. Pat
>
>
>Just a few things. First on retorques; the torque required to start a bolt
or
>nut moving is much higher than that required to keep it moving. So if you
torque
>a bolt to 50 lb/ft, stop, and then try to simply tighten it a little bit
more,
>to say 55 lb/ft, you may find that the bolt will not turn any further and
will
>appear to be torqued to 55 lb/ft even though you only torqued it to 50
lb/ft.
>This is especially true if the bolt sat for some time and/or went through
>several heat cycles. If you want to retorque a fastener, you really need to
>loosen it and retorque it. If you simply try to tighten a fastener again to
the
>same spec it was already tightened to, without loosening it first, it will
not
>move even if it has "loosened" up, and the actual torque is 5-10 lb/ft less
than
>what you have your torque wrench set to. Second, while the idea of an
additive
>in the coolant to "lubricate" the water pump is often used to aid sales,
and
>while most folks seem to buy into the concept, I believe it lacks a good
>scientific basis. The bearings do not run in the coolant, there are no
parts of
>the water pump that run in the coolant that are subject to wear or that
need
>lubrication. The bearings are really the only wear parts in a pump and they
are
>sealed well away from the coolant and lubricated separately. So just what
does
>the antifreeze or additive lubricate, Seals? They are lubed with the
bearings or
>are self lubricated. While they do ride in the coolant on the one side, I
have
>never seen anywhere any indication that they need special lubricants in the
>coolant. OTOH the one thing that all cars, and especially those with
bi-metal
>engines, need in the coolant is some sort of corrosion protection.
Antifreeze
>will give you a certain level of this. Even better is water with a good
>corrosion inhibitor additive, or water and RedLine WaterWetter, which is
also an
>excellent corrosion inhibitor.
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