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Re: 2L Head gasket

To: datsun-roadsters@autox.team.net
Subject: Re: 2L Head gasket
From: Marc Sayer <marcsayer@home.com>
Date: Thu, 22 Mar 2001 21:17:08 -0800
"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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