The Ford Barn

Hoovercw · 11-23-2017, 07:54 PM

Does the second version of the A manifold ( reinforced bit aft of #4) have the same priblem with sagging as the first version? Are the new ones available today any better at keeping their shape as the original? Do the manifolds with the heater stay in shape better because of the extra surface to dissipate heat?

Mike Peters · 11-23-2017, 08:09 PM

I've seen sag on both versions of original exhaust manifolds. If the sag is significant enough that gland rings cannot be installed, then buy a new manifold. There's no reason to think that the new manifolds won't eventually sag like the originals, but cross that bridge wen it comes. Most Model A's aren't driven enough miles over rough roads to worry about manifold sag. Heater manifolds seem to be built heavy enough to withstand sag. When purchasing an original manifold, it is prudent to carry a straight edge to measure exhaust port line up.

BILL WILLIAMSON · 11-23-2017, 08:17 PM

Yo' Mike,
I've "thought" about a flat iron bar, welded to the head pipe & up to a manifold stud, to relieve the load & prevent SAGGING at the rear of manifolds. Thoughts, PLEASE.
Bill Bracket

Mike Peters · 11-23-2017, 08:29 PM

Bill: Good idea! That would take the weight off #4 exhaust port, which causes manifold sag in the first place. mike

taffrail · 11-23-2017, 08:58 PM

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I've always used the gland rings, even with heater manifolds. The Otwell and Autolite I have are milled for the rings.

11-23-2017, 07:54 PM	#1
Hoovercw Member Join Date: Mar 2017 Location: Memphis, TN Posts: 63	Manifold sag Does the second version of the A manifold ( reinforced bit aft of #4) have the same priblem with sagging as the first version? Are the new ones available today any better at keeping their shape as the original? Do the manifolds with the heater stay in shape better because of the extra surface to dissipate heat?

11-23-2017, 08:09 PM	#2
Mike Peters Senior Member Join Date: Aug 2012 Location: South East Wisconsin Posts: 1,279	Re: Manifold sag I've seen sag on both versions of original exhaust manifolds. If the sag is significant enough that gland rings cannot be installed, then buy a new manifold. There's no reason to think that the new manifolds won't eventually sag like the originals, but cross that bridge wen it comes. Most Model A's aren't driven enough miles over rough roads to worry about manifold sag. Heater manifolds seem to be built heavy enough to withstand sag. When purchasing an original manifold, it is prudent to carry a straight edge to measure exhaust port line up.

11-23-2017, 08:17 PM	#3
BILL WILLIAMSON Senior Member Join Date: Dec 2010 Location: FRESNO, CA Posts: 12,560	Re: Manifold sag Yo' Mike, I've "thought" about a flat iron bar, welded to the head pipe & up to a manifold stud, to relieve the load & prevent SAGGING at the rear of manifolds. Thoughts, PLEASE. Bill Bracket __________________ "THE ASSISTANT GURU OF STUFF"

11-23-2017, 08:58 PM	#5
taffrail Senior Member Join Date: Dec 2010 Location: Hingham, MA Posts: 135	Re: Manifold sag Sponsored Links (Register now to hide all advertisements) I've always used the gland rings, even with heater manifolds. The Otwell and Autolite I have are milled for the rings.

11-23-2017, 08:29 PM	#4
Mike Peters Senior Member Join Date: Aug 2012 Location: South East Wisconsin Posts: 1,279	Re: Manifold sag Bill: Good idea! That would take the weight off #4 exhaust port, which causes manifold sag in the first place. mike