Manifold out... now What?

[roscoFJ73]

I had my 1HZ manifolds sand blasted and machined and they come up real pretty.
I think the inlet manifold was alloy hence the different colour

 

[gnavarroo]

Datz' naaaaah-ice!!!

I had my 1HZ manifolds sand blasted and machined and they come up real pretty.
I think the inlet manifold was alloy hence the different colour

That's really nice man! My buddy's got a bead blaster. Maybe I can bribe him into blasting my manifolds for a couple of gallons of local brew!!!

 

[gnavarroo]

Manifold heat riser isulator from SOR

For those of you out there that have tackled the manifold job, has anyone also ditched the heat riser valve for the heat riser insulator? I'm still having parts trickling in via ups from C-dan and Autozone... Was thinking about doing the heat riser insulator deal, getting rid of the "flap" . has anyone had any luck with this product? I've got it sitting in my sor.com shopping cart, ready to buy. Just thought I'd double check with ya'll.
Thanks

This thing here is what I'm talking about...

http://www.sor.com/sor/cat044.tam?xax=18007&anchor=#044-12C

Heat riser insulator sold by SOR

 

[chitown40]

That piece is not a replacement for the flap. The flap should remain in place, and if not working properly and you are not interested in purchasing a new manifold, you have to make sure it is the closed position directing heat into the exhaust pipe and not towards the intake manifold. The insulator is used in between the two manifolds. The correct order should be gasket + insulator + gasket.

 

[gnavarroo]

That piece is not a replacement for the flap. The flap should remain in place, and if not working properly and you are not interested in purchasing a new manifold, you have to make sure it is the closed position directing heat into the exhaust pipe and not towards the intake manifold. The insulator is used in between the two manifolds. The correct order should be gasket + insulator + gasket.

So the thing to do is leave the flap in? Even if it looks like the picture above? The flap or valve can be replaced with out having to replace the entire manifold. C-dan has them or can get them... The thing is, the bolts that hold the flap on the shaft seem to be melted or rounded... can't tell which. I was going to grind the bolt heads off, pull the flap and install the insulator... (between the two manifolds). Your saying to leave it in there, no mater what the condition? How do you make sure that it stays in the Closed position?
TIA

GN

 

[Mr. Toad]

I've installed one of those insulators. My installation left the flap in place.

As I said in my previous post (and as Chitown40 reiterated), it would probably be best to re-attach the intake manifold to the exhaust manifold with the flap (or what remains of it) in the closed position. The flap (even a new one) will not be able to rotate through its full range once the insulator is installed. Why would you install a new flap that will not serve any function after the insulator is mounted?

 

[gnavarroo]

The spring on the heat riser shaft: holding flap open or closed when cold??

I've installed one of those insulators. My installation left the flap in place.

As I said in my previous post (and as Chitown40 reiterated), it would probably be best to re-attach the intake manifold to the exhaust manifold with the flap (or what remains of it) in the closed position. The flap (even a new one) will not be able to rotate through its full range once the insulator is installed. Why would you install a new flap that will not serve any function after the insulator is mounted?

What about the spring attached to the shaft on the outside of the heat riser chamber/area? Does anything need to be done to it? Right now that spring is tensioned so that the chamber is shut (ie exhaust would be directed into the exhaust manifold). I mean it's under a good load at this default closed position. I thougt that the default, or cold position was the open position, hence allowing hot air to reach the intake manifold to heat up the carb... once the temperature rose to a high enough temp it would effect the spring and cause the shaft to turn and CLOSE the flap? Is mine wrong? It seems backwords to me if this is the pupose of the spring...
I dont Know
GN

 

[Mr. Toad]

What about the spring attached to the shaft on the outside of the heat riser chamber/area? Does anything need to be done to it? Right now that spring is tensioned so that the chamber is shut (ie exhaust would be directed into the exhaust manifold). I mean it's under a good load at this default closed position. I thougt that the default, or cold position was the open position, hence allowing hot air to reach the intake manifold to heat up the carb... once the temperature rose to a high enough temp it would effect the spring and cause the shaft to turn and CLOSE the flap? Is mine wrong? It seems backwords to me if this is the pupose of the spring...
I dont Know
GN

If you're not leaking exhaust at the flap's shaft where the spring is, then leave it be.

Your description of the flap operation is spot on. The top of the flap should be pointed away from the head in the cold, or open, position. When the spring heats up, the top edge of the flap rotates over so that it's pointing towards the head, in the closed position.

With the state of your flap, it might not really matter too much where it is when you install the insulator provided that there's clearance.

 

[gnavarroo]

Indications of exhaust leak at heat riser shaft?

If you're not leaking exhaust at the flap's shaft where the spring is, then leave it be.

Your description of the flap operation is spot on. The top of the flap should be pointed away from the head in the cold, or open, position. When the spring heats up, the top edge of the flap rotates over so that it's pointing towards the head, in the closed position.

With the state of your flap, it might not really matter too much where it is when you install the insulator provided that there's clearance.

I'm just wondering how to install the insulator, with valve closed or open and what to do with the spring ( all parts should be in next week). I don't know if there was ever a leak at the shaft... could have been. I was getting some heavy exhaust fumes coming into the cab. I prey that this "manifold operation" cures the problem (GF will not ride in 60/will not let GSD ride either=Pisses me off) Now I've got the manifolds out in pieces, waiting for parts... Any way to tell if there was a leak at the shaft? what are indications ie carbon tracks, etc..?
TIA

GN

 

[chitown40]

Ok, you're in New Mexico so you;re not going to be getting sub-zero temps where warming up the carb will be a najor issue. So, to address several of your questions here goes. First, I wasn't aware you could replace the flapper and the FSM states to replace the manifold if the flapper and spring go bad, but I'm not one to argue with c-dan's knowledge, so let's assume you can. You buy the flapper and spring and re-insatll it, then all you need is your stock insulator and two gaskets. Since you'd be sure that the flapper will be working properly because you have a new bi-metal spring in place, there would be no need for the SOR insulator. FYI, there is another thread that just popped back into circulation about people that have had bad leaks when using the SOR insulator due to its thickness.

If you use the SOR insulator, and keep your warped flapper, then you need to somehow secure the flapper in the closed position (so the exhaust is directed downwards towards the pipe as opposed to upwards towards the intake). You can either weld it is place, or do what I did and undo the end of the bi-metal coil and crank it so the flapper moves into correct position and then reattatch it tot he manifold. I did this because my coil stopped reacting to heat and opening the flapper about one month after I put it all back together so I needed a quick fix until I coul dtear it all down again. Whatever method you choose to do, make sure it stays in the correct position for normal operating temp.

Landpimp said a new set of manifolds from c-dan was about $600 for both and well worth it if yours are questionable. Also, if you choose to replace the manfolds with used ones, make sure you get a complete set and don't mix and match if you don't have to. (dd113 recommendation to me a while back). Then have them cleaned up and planed at a machine shop before reinstalling.

Hope that helped at least a little bit.