350 chevy crate motor rocker arm nut torque?

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mike

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Jun 28, 2004, 11:40:04 PM6/28/04
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I replaced the head gaskets on my Chevy 350 300HP crate motor (part #
12355345) and am waiting on some more parts. Does anyone know offhand what
the torque is on the rocker arm nuts? I believe it is around 40 foot pounds
but am not really sure. Does anyone know of an online manual for the torque
settings on these engines? Thanks.


mike

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Jun 29, 2004, 5:18:23 AM6/29/04
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mike wrote:

Now I'm confused. When removing the rocker arms I could have sworn they
were torqued on. It just seemed that they all took a set amount of
"torque" to loosen. I found a page online that said that they are
"zero/zero" lash. Are these adjustable rockers? I think the heads are the
same castings as a 88-92 350 L-98 Camaro.

Eugene Blanchard

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Jun 29, 2004, 2:44:25 AM6/29/04
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If its hydraulic lifters than you adjust them not torque them. What year is
the engine? I just put together a 400 cid sbc and had some fun adjusting
the tappets (rocker arms) using the "rocker arm nuts". I put a webpage
together on it at my 54 Pontiac DIY website (Do It Yourself)

http://www.cadvision.com/blanchas/54pontiac/tappets.html

mike

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Jun 29, 2004, 8:07:41 AM6/29/04
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Eugene Blanchard wrote:

> If its hydraulic lifters than you adjust them not torque them. What year
> is
> the engine? I just put together a 400 cid sbc and had some fun adjusting
> the tappets (rocker arms) using the "rocker arm nuts". I put a webpage
> together on it at my 54 Pontiac DIY website (Do It Yourself)
>
> http://www.cadvision.com/blanchas/54pontiac/tappets.html

My brother got it new from a Chevy dealer in Wash. about 2 years ago. It
was a long block and Chevy just called it CHEVY 350 300HP HI-PO. The part#
is 12355345. It's in a '42 Chevy pickup. The lifters are hydraulic but we
were looking at a '80's Chiltons Chevy pickup repair manual. It said to
torque the rockers to 40 foot pounds and since this engine looks like the
ones listed that's what we thought what to do. I believe we are very
wrong.


382584477666

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Jun 29, 2004, 9:03:50 AM6/29/04
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"mike" <non...@spams.com> wrote in message
news:pdOdnVFEmIE...@giganews.com...

The adj. NUT is crimped at its top causing a drag / tightness so it can hold
it self. NO TORQUE in needed on the rocker arm nut. What would be the
method used at the factory ??? are the nuts adj while running (NO) are the
nuts adj when the lifters are full of oil??? (NO) they adj. so fast it would
scare you and its by a 1/2 adjusted method when 6 is up turning the engine
over to 1 up to adj. the other 8 nuts and the other 8 are obvious there the
ones not turned down to the proper adj.
Different ways for different people to each there own. I adj. the 6 up to
the 1 up method. If its a re-adj. I bleed-down the lifters for a short time
1st., then un adj. them and find 1 or 6 up then adj for the final time.
Side note... when 1 is up both the in. and ex. are adj. same when 6 is up
the rest of the sequence should be findable in a repair book, its only been
being printed since 1955.


Bob May

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Jun 29, 2004, 12:40:21 PM6/29/04
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The nuts are not torqued to some point but rather are adjusted to provide
the correct position for adjusting lash on the valve drive train. The nuts
are special nuts that have some upset threads so that there will be a fair
bit of force needed to move them.
The basic process is to find the point at which the valvetrain is at 0" lash
without the lifter collapsing any and then turn the nut another 1/2 turn
down to put the lifter in the near middle range of its adjustment range.

--
Bob May
Losing weight is easy! If you ever want to lose weight, eat and drink less.
Works every time it is tried!


cc

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Jun 29, 2004, 8:52:31 PM6/29/04
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I used to adjust the sb valves running! (this was in mid 60's), I still have
the clips that go on the rockers to prevent oil from squirting
everywhere....loosen until they start "clacking" then tighten up until it
stops then tighten 1 1/4 turn then go to the next one....on the older cars
we always adjusted the valves with the engine running, I have many feeler
gauges with the ends eaten up by the valve ends slamming the rocker stud,
and it was fun with some engines that had a lock nut that had to be loosened
then adjust the rocker then tighten the lock nut! (all while the engine was
running) ....it was fun?....cc


382584477666

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Jun 30, 2004, 8:24:09 AM6/30/04
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"cc" <cosmic...@adelphia.net> wrote in message
news:yZOdncgvyIz...@adelphia.com...


Most books say one turn........... [cc said 1 and a 1/4 turn]
..............[bob said 1/2 turn].........I've seen some do what's
missing..........i.e.: 1/4 turn..........and 3/4 turn......and
1turn.........it has been open to debate as to what is best. Racers (mostly)
use the smaller... like 1/4 to 1/2 its for RPM reasons I've used all the
1/4's and the 1/2's and the 3/4's with everything being ok and never had a
problem and never used more.

I prefer the dry method 1up -6up. Clips seamed to work better than the wire
plastic hole pokers. Cutting the holes in old valve covers had to be cut
just right as to cover the oil splash, tight slit in cover, that and
clips seamed to work the best,(for me doing a running engine).


Eugene Blanchard

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Jul 2, 2004, 2:15:08 AM7/2/04
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the torque spec could be for screwed in rocker studs? The early chevys had
pressed fit rocker studs. Don't know about the later models. The rocker arm
nuts are usually adjusted unless there's something I'm not aware of which
wouldn't be the first time.... I thought that I was wrong once but I was
mistaken...

mike

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Jul 3, 2004, 10:59:14 PM7/3/04
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Eugene Blanchard wrote:

> the torque spec could be for screwed in rocker studs? The early chevys had
> pressed fit rocker studs. Don't know about the later models. The rocker
> arm nuts are usually adjusted unless there's something I'm not aware of
> which wouldn't be the first time.... I thought that I was wrong once but I
> was mistaken...

No, you were right. We set the lash to zero then just gave it an extra half
turn. Runs great. Thanks.

glenda...@gmail.com

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Apr 23, 2016, 9:36:43 AM4/23/16
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It is a 72chevy 350

Terminal Crazy

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Apr 23, 2016, 2:21:55 PM4/23/16
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In article <ed178a39-f3e0-414e...@googlegroups.com>,
<glenda...@gmail.com> wrote:
> It is a 72chevy 350
Doesn't matter. Read up on what you're trying to do.

You set the Valve lash by adjusting the nut.
They don't torque up as such, like the ford cleveland Non adjustable
fulcrum rockers.

Mitch

--
Terminal_Crazy

Mitch - 1995 Z28 LT1 M6 termina...@sand-hill.freeserve.co.uk
Lancashire England http://www.sand-hill.freeserve.co.uk/terminal_crazy/

devondu...@gmail.com

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Jan 9, 2017, 1:57:02 AM1/9/17
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Tighten till theres no up\dwn play in rods. Then crank it with head covers off. Then tighten till tap is gone. Plus quarter to full turn. Dnt makr it more difficult then it needs to be guys.

jameshge...@gmail.com

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May 8, 2020, 6:12:40 PM5/8/20
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What about an 88 corvette?

jameshge...@gmail.com

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May 8, 2020, 6:14:32 PM5/8/20
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Mine is an 88 corvette
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