Exhaust Manifold Question

[NP2650]

I’m working on my exhaust manifold and have a question about the gate that allows exhaust air into the bottom of the intake manifold. I have three exhaust manifolds and the gates in all of them are stuck solid – and all three are stuck in various positions. My question is what to do with this gate. Do you ignore it, remove it, or work like heck to get it to operate again? It also looks like the position of the gate is set manually. Is this correct?

[Gordon Maney]

I’m working on my exhaust manifold and have a question about the gate that allows exhaust air into the bottom of the intake manifold. I have three exhaust manifolds and the gates in all of them are stuck solid – and all three are stuck in various positions. My question is what to do with this gate. Do you ignore it, remove it, or work like heck to get it to operate again? It also looks like the position of the gate is set manually. Is this correct?

Yes, it is set manually, and yes, you would like to free it so it works.

[Matthew Ziegler]

exhaust manifold

that gate was put there to direct more heat to your intake manifold for better fuel atomization during cold weather, I belive someone sells a kit to replace the often rotted away or missing plate and shaft assemblies, personally my truck does not have one. I had a short timeframe to get it on the road for an upcoming show so I tapped the two holes and plugged them with short bolts, truck runs great. my theory is the cast iron manifold is going to get hot regardless and transfer heat to the intake manifold, also after adding a performance cam and shaved head, I couldn't justify adding any restriction to the exhaust. just my two cents

[Gordon Maney]

It was not uncommon for people to just leave them in the middle position.

[gmharris]

You don't need it unless you are planning on driving in very cold weather. I don't think it's worth taking off a manifold just to fix it. I would guess that it's not working on most trucks. It shouldn't be a problem unless the valve is stuck in the winter position.

I recently took off the exhaust pipe off the manifold on one of my trucks and saw the flapper had fallen off and stuck in the exhaust pipe. Kind of strange since the flapper looked in perfect condition.

[oldmopar]

See the link below for a good explanation of the heat riser valve

http://mopar.pairserver.com/p15d24ph...r_adviser.html

[Matthew Ziegler]

spring

I've seen the spring setup on a 42 ford I own, my m37 and a friend's wc52 both had a triangular plate with a slot in it, you adjust the position with a wingnut. did the civillian trucks have this spring?

[wayneh]

VPW sells a kit to replace/fix it. Not too expensive. When I had my manifold off I re-did that thing after I had the manifold ceramic coated. Frankly though, where I live in Maryland I'm not driving it when it is 20 below zero (cause it never gets that cold here....) and I can't tell any difference from open to closed mode. If you fix it, you do need to weld the flat butterfly type gate on the shaft.

Wayne

[defdes]

I am about to replace my manifold and have a question about the gate also.
My replacement manifold has only one bung that has been plugged, it lacks the lower hole where the spring mechanics attach.
I live in VT and use this truck to plow, so I will be driving it in weather as low as single digits to low teens. Should I drill the second needed hole, or just try it as is initially and see how it goes?
Also, the reason I need a new manifold in the first place is that the PO didn't use the conical nuts and washers and the manifold cracked in numerous places, is there a cross over Dodge from which I could them or a place to order these from?

[Gordon Maney]

If you know exactly where it goes, I guess it couldn't hurt.

As I sit here I don't know if any Power Wagon had a thermostatically controlled valve. I wonder about the origin of this engine. Or manifold.

[defdes]

I suppose so...and what about the whereabouts of the exhaust flange nuts and washers?

[Gordon Maney]

I suppose so...and what about the whereabouts of the exhaust flange nuts and washers?

I am unsure as to what you are meaning.

[defdes]

I am unsure as to what you are meaning.

It was my understanding that exhaust manifolds were equipped with a thick concave conical shaped brass washer with a convex conical brass nut which seated within. The brass and shape allowed for the difference in expansion/contraction rates between it and the head and helped prevent cracking as I am showing on my motor. Sound familiar?

[Gordon Maney]

OK, yes, thank you.

[defdes]

Tangent!

I suppose so...and what about the whereabouts of the exhaust flange nuts and washers?