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exhaust manifold questions
https://slantsix.org/forum/viewtopic.php?t=46209
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Author:  87D100 [ Sun Sep 04, 2011 6:35 am ]
Post subject:  exhaust manifold questions

I got an exhaust manifold from the salvage yard yesterday to replace the broken on in my 87 D100. It is an older manifold, came from an A100 van of unknown year because it was the only slant with a manifold in the yard, these things are hard to find around here. Does anyone have a choke coil laying around that will work with this manifold and my 1945 carb? Also, the manifold is missing the bimetallic coil for the heat riser and the counterweight, is there a way to remove these from my original manifold and retrofit them to the older one? if not, what would be the best compromise in new england, no manifold heat or full time manifold heat?

thanks
Kevin

Author:  SlantSixDan [ Sun Sep 04, 2011 8:31 am ]
Post subject: 

This isn't a good match. There's no way to remove and replace the heat riser parts without cutting the shaft and then installing new parts which requires welding. And if your '87 has feedback engine control w/oxygen sensor, the earlier manifold isn't compatible anyhow, but either way it doesn't sound like the manifold you picked up is in good enough shape to be worth the time and effort to swap it on; get a new aftermarket one for $110. It is very much worth your while to get the good gaskets for the manifolds-to-head and intake-to-exhaust junctions.

If you push forward with using this exhaust manifold, use a #1234 Electric choke kit.

Author:  87D100 [ Sun Sep 04, 2011 9:23 am ]
Post subject: 

I appreciate the advice, but a new manifold is out of the budget as is the electric choke. (It costs twice what I paid for the manifold after shipping).
If I have to I'll simply hook up a manual choke.

The O2 is a non issue as I have no feedback on this truck.
for that matter welding is a non issue either.

I would like some more opinions on the heat riser, upon closer inspection my original one was just flopping around, would I be better off with it always open or always closed. I've never run this truck on the road, so I have no basis for opinion on driveability, I paid 200 for the truck not running, got it running with a 25 dollar carb kit only to find the manifold outlet broken off right up through the heat riser

thanks
Kevin

Author:  Jeb [ Sun Sep 04, 2011 9:35 am ]
Post subject: 

Just tack the heat riser in the closed position, that way you will have at least some carb heat. You'll just have to baby it a little more on the cold mornings.

Author:  87D100 [ Sun Sep 04, 2011 9:42 am ]
Post subject: 

thank u, that is exactly what I wanted to here and re-affirms my own feelings. I always let my carb vehicles come up to full operating temp in the winter months anyway before taking off.

Kevin

Author:  ceej [ Sun Sep 04, 2011 10:01 am ]
Post subject: 

Does the manifold you got from the bone yard have a heat riser? I ran one without for years prior to changing over to a custom exhaust system.

Without the heat riser, don't worry about it too much. Sounds like you have the warm up routine figured out.
I can start in freezing weather with Dual Dutra Duals, which don't connect to the intake manifold. Takes a little coaxing until it will idle but it's manageable. I have no choke. Not the most efficient way to start up, but it can be accomplished easily enough.
Even without the physical connection between the intake manifold and exhaust, the intake will eventually heat soak.

2¢

CJ

Author:  87D100 [ Sun Sep 04, 2011 10:40 am ]
Post subject: 

The manifold does have the butterfly in it, just none of the stuff to make it work. So are u saying to just cut the butterfly out and never think about it again? That may be a valid solution

Kevin

Author:  Fopar [ Sun Sep 04, 2011 10:56 am ]
Post subject: 

Or just block the flap in the no exhaust heat position.

Richard

Author:  ceej [ Sun Sep 04, 2011 11:10 am ]
Post subject: 

Not exactly. I have a truck manifold that never had a provision for the heat riser. If it was one of those, I wouldn't worry about it.

If you completely remove the heat riser and braze up the shaft holes, your manifold will be similar to the one I was running.

The best bet is to repair it so that it operates normally for driveability and year round economy. If the vehicle is a daily driver, plan on fixing it at some time in the future. For a sporadically driven vehicle, locking it in position can be an option. So long as the deflector is still solidly affixed to the shaft, it shouldn't present long term issues. If it comes loose, it can partially obstruct the exhaust manifold which can result in very high manifold temperatures and reduced performance.

The FSM goes into detail about installing a new one. I don't know if you can still purchase the parts to accomplish this. With some care, you may be able to use parts from the old one to make yours functional.
It would take more time and skill than money. Sounds like you have the tools you need to accomplish the task. It just comes down to how much time you want to throw at it.

Locking the deflector plate is certainly an option.

CJ

Author:  87D100 [ Sun Sep 04, 2011 1:29 pm ]
Post subject: 

I think I'm just going to lock it closed, I feel that there will still be enough radiant heat there to make it livable. It's not like there's an air space like your Dutra setup, I feel the heat conduction through the manifold will be sufficient.

Kevin

Author:  ceej [ Sun Sep 04, 2011 1:44 pm ]
Post subject: 

Sounds like a plan. We have plenty of folks running headers year round as well. They always seem to be able to get around. :D

CJ

Author:  olafla [ Sun Sep 04, 2011 4:20 pm ]
Post subject: 

Hi 87D100, I have no scanner where I am right now, but I can try to photograph the manual pages covering the heat control valve repair, and have them ready for you in a couple of hours. It is always interesting to see what solutions mother Mopar has to offer!

Olaf.

Author:  olafla [ Sun Sep 04, 2011 5:48 pm ]
Post subject: 

Here is a link to a larger version of the manual page below. It's about 1.7Mb, so save it to your own machine before opening it.

Image

Olaf.

Author:  87D100 [ Sun Sep 04, 2011 6:56 pm ]
Post subject: 

thank u for that Olaf, I may try to remove the counterweight an spring from my broken manifold and attach it to the "new" manifold.

Kevin

Author:  lancer61 [ Mon Sep 05, 2011 12:21 am ]
Post subject: 

Quote:
but either way it doesn't sound like the manifold you picked up is in good enough shape to be worth the time and effort to swap it on; get a new aftermarket one for $110
So where can I get one for $110 ? most places I have looked at wants up around $200-250.

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