Headgasket Replacement Tip (headbolt prep)

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xirdneh
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Joined: Thu Aug 04, 2005 11:38 am
My tercel:: 87 tercel 4x4 wagon w/reringed engine, 83 tercel 4x4 wagon w/salvaged engine and 4.1 Diff's
Location: seabeck, washington, USA

Headgasket Replacement Tip (headbolt prep)

Post by xirdneh »

I was talking to a friend about torqueing the headbolts
he told me that when he was a young man an older timer was helping him replace a headgasket
the old timer told him a torque wrench is useless if you do not chase the threads in the block
and clean up the bolt threads
I was doing a headgasket job this week so I bought a 10 x 1.25 metric tap and ran it down all ten bolt holes in the block
some had carbon deposits
I wire brushed the threads on the bolts
lightly oiled the bolt threads and both sides of bolt washer
torqueing the head went like a dream
I did it in three passes 20, 35, 47 and every one felt the same all the way thru
that is one thing that never happened before
Love those Tercell 4x4 wagons but they sure suffer from road noise.
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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Headgasket Replacement Tip (headbolt prep)

Post by Petros »

It was normal procedure when I worked for Nissan, that when we rebuilt a race engine to chase the threads in the block for the head bolts on each rebuild. I have not done that at home since I did not have a tap that large, but I do wire brush both the bolt threads, and use a wire brush in the bolt holes with lots of solvent, and keep cleaning the threads until the solvent comes out clean. Though chasing the threads with a tap is an important thing to do if there is any build up, corrosion or possible thread damage.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
teranfirbt
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My tercel:: '86 SR5 4WD, 5AFE, lifted rear, 195/70/14 tires
Location: Seattle, WA

Re: Headgasket Replacement Tip (headbolt prep)

Post by teranfirbt »

Have definitely paid the price when I was younger for not chasing head bolt threads. I've got an old head bolt with a couple of slots for gunk that I use to get the crusties, then a .45 caliber bore brush on a drill for final cleaning.
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