Fordnatics List Archive

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Mail From: (email redacted)


I was replacing a blown head gasket on my mustang this weekend and ran into
some troubles.

Does anybody know the correct torque spec. for the head bolts on an '86
5.0L? I've got the Helm/Ford shop manual for the car but it appears to have
a misprint. Under the torque specification table for cylinder head bolts
it only list footnote 11. Footnote 11 says to retorque with engine hot after
assembly. I checked the spec. for a 351 and it list footnote 10 which is a
3 step procedure ending with 105 ftlbs. I tried this and it was too much.
One of the bolts yielded at around 100 ftlbs. Footnote 9 list a 2 step
procedure ending with 72 ftlbs. I suspect this is the right one as it matches
the numbers in my old '68 cougar manual. At this point I need some kind of
definitive answer.

Also, does anybody have a favorite thread sealing compound for the threads
on the lower bolts? These bolts go through to the water jackets. I'm sure
Permatex must make something.

I can't resist making a few random comments while I'm here. The rear lower
intake gasket was out of place from the factory (bad Ford). There was a full
1" that was not getting sealed. I've heard of other people finding this same
problem. So if your leaking oil from the rear of your engine you should
consider changing this.

My engine has 145K miles on it and not only was there no noticeable ridge on
the cylinder walls but I could still see the honing marks (good Ford). Also,
there was no varnish on the rockers or valve covers. FWIW I've changed my oil
religously at 3K intervals with plain old Pennzoil. I do use synthetics at
the track but this has only been half a dozen times. So wherever you fall
on the synthetic vs. dino oil debate, I'd still advocate frequent changes.

Thanks in advance.

-Karl

*********************************************************************
Karl Brandt Center for Integrated Systems
(email redacted) Via Ortega Rd.
(415) 725-3686 Palo Alto, CA 94305-4070

"There's nothing a good day at the track can't fix"

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Mail From: Dan Malek <(email redacted)>


> Date: Mon, 03 Apr 95 09:15:02 PDT
> From: (email redacted)
>
>
>I was replacing a blown head gasket on my mustang this weekend and ran into
>some troubles.

>Does anybody know the correct torque spec. for the head bolts on an '86
>5.0L?

You should be using the latest Fel-Pro gasket set that includes torque
spec instructions. The instructions basically say they have done lots of
testing with Ford, and these new torque specs are to be followed instead
of anything printed in any manual. As I recall, possibly incorrectly,
the long bolts are somewhere around 100 and the short ones around 80.

>Also, does anybody have a favorite thread sealing compound....

This also comes in the kit. The torque specs are probably affected by
the choice of goop used, so use the supplied stuff. Also, make sure
the threads are _really_ clean from the previous sealer. I run a thread
chaser into the block (try not to use a real tap because it will cut
threads instead of cleaning) and I always use new bolts (lots easier than
cleaning). Without clean bolts and threads here you are asking for
trouble.

Oh, yeah. My disclaimer. I don't gain anything from the Fel-Pro
recommendation. I have used them, and they appear to work.

I hope you have the same good luck.


-- Dan

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Mail From: "STEPHEN H 'STEVIE' GROSSEN" <(email redacted)>


I have a Mustang Performance handbook that lists the proper torque
sequence, but after reading all of the threads on this it seems I am day
late and a dollar short (they recommend Fel Pro Fel-Graphic head gaskets
and noted the intake manifold bolts trying to pry off the head). One
intersting point not mentioned on the thread was that it is very important
to recheck the torque after the engine was brought up to operating
temperature and allowed to cool overnight. According to the book, this is
due to the expansion and contraction of the thin wall casting of the 5.0
motor.

good luck
steve
(email redacted)

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Mail From: (email redacted) (Robert King)

> Dan Malek wrote:
>
> One of the new (relatively) discoveries by Fel-Pro was how intake manifold
> bolts tended to fight against head bolts in trying to pry up the heads that
> you just torqued down. As such, they now have new instructions on torque
> and retorque sequences after you have installed the intake manifold.
> So for proper head sealing, you REALLY need to follow Fel-Pro's instructions.

Ok, so when I have torque specs from Fel-Pro, and torque specs from ARP,
whose specs do I follow?

- -- Robert King


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| Robert A. King | |
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Mail From: Eugene Y C Chu <(email redacted)>

Actually, I think the torque specs should be similar between the Fel-Pro
and Ford instructions. Since ARP fasteners are supposedly stronger, I
would expect that they might give higher torque specs, and you would be
safe to follow them with their parts. But, what I was referring to is
the new torque and retorque sequence that Fel-Pro had recommended:
something like after you torqued down the heads, install the intake
manifold, toruing it down to specs, then check the head bolts again,
torquing them down again if necessary (most likely), and then check the
manifold again. (This may not be the exact sequence, so you might want
to consult some Fel-Pro instructions.) But do this BEFORE firing up
the engine for the first time, since a loose head gasket will be ruined
within the first heat up/cool down cycle, before you get a chance to
check it again after the first running.

eyc

This read-only message was archived from a public mail list.
Mail From: Dan Malek <(email redacted)>


> Date: Tue, 4 Apr 1995 12:49:43 -0500 (CDT)
> From: Robert King <(email redacted)>
>

> Ok, so when I have torque specs from Fel-Pro, and torque specs from ARP,
>whose specs do I follow?

The ones from ARP.

I forgot to mention in the past that the torque sequence is just as
important as the torque value. The gasket manufacturer is sensitive to
torque sequence, so I doubt you will get this from ARP. I have never
used ARP bolts in a 5.0 block that has the bottom short bolts open to
the water jacket. You will have to call ARP to determine what they
recommend for thread sealing and torque procedure. In addition, you
may want to call Fel-Pro and ask for their advice (or references) when
using ARP bolts.


-- Dan

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Mail From: (email redacted) (Dave Williams)


-> assembly. I checked the spec. for a 351 and it list footnote 10 which
-> is a 3 step procedure ending with 105 ftlbs. I tried this and it was
-> too much. One of the bolts yielded at around 100 ftlbs. Footnote 9
-> list a 2 step procedure ending with 72 ftlbs. I suspect this is the
-> right one as it matches the numbers in my old '68 cougar manual. At
-> this point I need some kind of definitive answer.

The 72 ft-lb figure is about right. I'm not surprised the 105 sacked
your head bolt - you should dump them all, BTW. You have seriously
overtorqued the bolts. The 351 uses 1/2" head bolts, the 302 only
7/16".


-> Also, does anybody have a favorite thread sealing compound for the
-> threads on the lower bolts? These bolts go through to the water
-> jackets. I'm sure Permatex must make something.

None of my Ford manuals call out anything. I like KW Kopper-Kote -
it's not as much of a hassle to get out of the threads later.