Manifold Installation

[Charles Reese]

Waiting on Santa so got to thinkin ….. any tips on installing the exhaust/intake manifolds… order of tightening nuts (i.e. nut #2-3, then 1-4; or does it really matter), how tight, tighten to block before tightening intake to exhaust manifold bolts etc., etc. ??

This will be done with garage temp in the 50s so have concerns about metal expansion once engine is started (i.e. breaking ‘ears’ of the manifolds).

[tbirdtbird]

35 ft lbs torque only to block. manifold shrinks and expands greatly with temp swings and must be allowed to move underneath the nuts/studs. Else it will crack or distort

[smurph]

Just finished this job. Ordered exhaust manifold from Bratton's (page 60, part # 13690). Very fine quality casting.
Instructions call for torquing to 45 pounds, a little at a time spacing the pressure among all four nuts. I tightened 2,3,1,4.
You will need to retorque to 45 pounds after you have started engine and when everything is hot. Maybe several times.
You will also have to check (with a straight edge) that intake and exhaust manifolds are perfectly level. If not then they will need to be "decked". Also check the fit of the glands. Manifolds must mate to the block without gasket in place. If not glands will need to be ground down.
Good luck,
Smurph

[msmaron]

Work from inside nuts OUT!!! Tighten exahut only and finger tighten intake. Torque to 30#, run...tighten intake tight. torque exhaust to 35, heat, torque to 40#. Drive car........ Check torque up to #45 re tighten intake. Check fit with feeler gauge. Use copper gaskets only and take your time.

[Charles Reese]

exactly the kind of direct advice i'm seeking ... the beauty of FB and A'ers....

[msmaron]

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Charles just go slow. Do you have the E28 hump

[Bick in New Zealand]

Do you have the E28 hump ?

[Dick M]

Be sure to have the exhaust and intake manifolds surfaced prior to installation. They must be mated together when surfaced. Any machine shop can do the job. This step will insure an even mating of the manifolds to the block which provides for a good seal. You do not want any leaks.

[Charles Reese]

Originally Posted by Bick in New Zealand

Do you have the E28 hump ?

Yes, indeed

[msmaron]

Charles remember that when you have it planned to the manifold it will only mate with that one.

[Charles Reese]

Originally Posted by msmaron

Charles remember that when you have it planned to the manifold it will only mate with that one.

that's why i really dont want to break 'em ... been chasing insidious fuel leak and water seeping at head/block ... took manifolds off to touch up paint ... couldn't locate my notes with installation tips (order, torque, etc) so posted ... thanks for helpful responses

[Duffy1]

Good chance you will crack the manifold if you tighten it to 45#. Watch the gasket and when it starts to compress you have it tight enough . Do a search .Lots of posts on this subject.

[Tom Wesenberg]

I agree and only tighten to what feels comfortable. I don't use a torque wrench, but at a national meet about 8 years ago I saw a guy break his manifold before 35 pounds was reached.

[Purdy Swoft]

The main problem with over tightening is warping the exhaust manifold.

[Mitch//pa]

use a 3/8th hand ratchet, socket, extension and common sense....
then more common sense after a couple of hot and cold cycles

[Purdy Swoft]

Mitch is right on . That is exactly the way that I do mine.

[Mike V. Florida]

Originally Posted by Purdy Swoft

The main problem with over tightening is warping the exhaust manifold.

Originally Posted by Mitch//pa

use a 3/8th hand ratchet, socket, extension and common sense....
then more common sense after a couple of hot and cold cycles

I was told early on to ignore the torque ratings for the manifold and the oil pan. 10 years so far so good.

This is not to say many have used a torque wrench with success on these items.

[glenn in camino]

I usually tighten 2&3 first then 1&4. I check them again after a good warm up.

[Bick in New Zealand]

Do you have the E28 hump ?

What is the E28 hump?