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| Heat Riser Valve https://www.slantsix.org/forum/viewtopic.php?t=65450 |
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| Author: | slantfin [ Wed Oct 21, 2020 10:26 am ] |
| Post subject: | Heat Riser Valve |
There is a vacuum fitting on the heat riser flap, should it be connected to manifold vacuum or ported? How do you test the valve? I've been ignoring it, and I think it's leading to my slant six running too hot. |
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| Author: | cpslntdchrg [ Wed Oct 21, 2020 2:39 pm ] |
| Post subject: | Re: Heat Riser Valve |
Eh... not in mine. The heat riser flap is in the exhaust manifold, and divert hot exhaust gases to the bottom wall of the intake manifold, under the carb, and helps evaporate fuel while the engine is cold (and not sure if also during operation). It just work with a counterweight and a thermostatic spring (at least in a 1969). You just get sure it is not stuck, and pump some Mopar rust penetrant (Part No. 04318039AC) where the flap shaft rotates in the manifold holes every now and then (or when the service manual says, I don't recall now). If it is already stuck use the rust penetrant and try to move it gently back and forth until it ustucks. To test it: with a cold engine just carefully rotate it by hand (old model is a square counterweight, newer models the counterweight looks like a wheel), it should turn 1/4 of a turn. Start the engine, and you should see it closing as the engine warms up. You can buy the MOPAR rust penetrant in dealerships or the internet, and it works (better than standards rust penetrant, in my experience) and try that. Also, if you tell us your engine's year, maybe somebody can guide you better in your particular model. By the way I think it should not affect so much engine operating temperature, but if it was designed to work in a way and its not, better fix it anyway. |
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| Author: | slantfin [ Wed Oct 21, 2020 8:17 pm ] |
| Post subject: | Re: Heat Riser Valve |
Thanks for the response, it's not the original manifold, so that vacuum fitting is not covered in my 1967 shop manual. I have an extra manifold vacuum port on the carb, so I'm going to try hooking that up to the vacuum fitting on the riser valve. I'll do the visual check on the valve, that makes sense. |
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| Author: | cpslntdchrg [ Thu Oct 22, 2020 1:15 pm ] |
| Post subject: | Re: Heat Riser Valve |
Just to help us to help you, can you take pictures of the heat riser with the vacuum fitting, and of the manifold vacuum port in the carb (where it is)? Is the carb a 1967 Holley 1920? or the carburetor was changed also? (ie I have an 1973 Holley 1920 in my 1969, and it has more vacuum ports than the 1969). You can post the pics here (I heard is not easy), or share them in Google or Microsoft (or another picture website) and share the link. |
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| Author: | slantfin [ Thu Oct 22, 2020 7:36 pm ] |
| Post subject: | Re: Heat Riser Valve |
I'll see what I can do, I'm not very technical. I just added a 500 cfm Holley 2-barrel carb. |
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| Author: | rich006 [ Thu Oct 22, 2020 7:51 pm ] |
| Post subject: | Re: Heat Riser Valve |
It sounds like you might be talking about the door in the air cleaner horn, which is controlled by vacuum. The line to the door actually comes from the temperature sensor that is inside the air cleaner. That sensor has two fittings that poke through the bottom of the air cleaner. One goes to the flap/door and the other goes to the carburetor. The sensor sends vacuum to open the door only when the engine is cold. |
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| Author: | cpslntdchrg [ Fri Oct 23, 2020 7:25 am ] |
| Post subject: | Re: Heat Riser Valve |
Or you might be talking about the EGR (if you have a newer (super six?) intake manifold). You are installing 2 barrel carb, no?, so you might. The EGR will work with vacuum, but you don't need it in a 1967 (and its better just leaving it out of the system if you don't need to pass emission tests). There are block off plates you can install, or if I remember properly, you can uninstall it, turn it 180 degrees and install it again, and it will give you the same effect as blocking it. Not sure of anything that can be operated by vacuum in that area. That is why I was asking for pictures. |
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| Author: | Greg Ondayko [ Fri Oct 23, 2020 8:55 am ] |
| Post subject: | Re: Heat Riser Valve |
I dont think its a vacuum fitting. My 69 had a deicer or carb heat tube in the manifold. Yours might be similar. Ssd or mavtv91 will probably chime in with the facts. Greg |
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| Author: | cpslntdchrg [ Fri Oct 23, 2020 11:30 am ] |
| Post subject: | Re: Heat Riser Valve |
Well, that arrangement existed, but in US only the 1969 intake manifold have them, as from SlantSixDan comment on this thread. http://www.slantsix.org/forum/viewtopic ... 873#142873 (how do I know? I have a 69, and for a time I was looking on what to do with that hole. At the end, is sealed anyway). So, if the OP has a two barrel carb, he has a 2 barrel set up (newer than 1969) or have more modifications there than the ones we can think of. Another indication that is better having pictures to diagnose better. |
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| Author: | slantfin [ Mon Oct 26, 2020 8:08 pm ] |
| Post subject: | Re: Heat Riser Valve |
Sorry to lapse a couple of days, been replacing axle bearings. It's not the air cleaner door, I have an aftermarket paper element air filter on there. Also not the EGR valve, this is a vacuum fitting between where the exhaust manifold meets the heat riser flap valve. I'll try to get a snapshot of it tomorrow. |
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| Author: | slantfin [ Tue Oct 27, 2020 11:42 am ] |
| Post subject: | Re: Heat Riser Valve |
It has a part number 4104021 |
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| Author: | Charrlie_S [ Wed Oct 28, 2020 8:11 am ] |
| Post subject: | Re: Heat Riser Valve |
Quote: It has a part number 4104021
That is a EGR valvehttps://www.ebay.com/itm/1978-1981-Dodg ... _cvip=true |
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| Author: | Charrlie_S [ Wed Oct 28, 2020 8:12 am ] |
| Post subject: | Re: Heat Riser Valve |
Quote: Well, that arrangement existed, but in US only the 1969 intake manifold have them, as from SlantSixDan comment on this thread.
That is on the exhaust manifold. I actuall have one of those manifolds, New in the box.
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| Author: | cpslntdchrg [ Wed Oct 28, 2020 8:32 am ] |
| Post subject: | Re: Heat Riser Valve |
Quote: It has a part number 4104021
Ok, the EGR, thanks Charrlie_S. You don't need it unless you plan/need your emission system working in New England... The best thing is to replace it with an EGR block off plate (i.e.:https://www.ebay.com/i/223774137859?chn ... gIaffD_BwE Probably you can find better/cheaper options, or do one yourself) Another option is to install it with the arrow pointing to the rear on the valve's body (see Charrlie_S link) pointing to the front of the engine, in such condition the valve wont operate (not sure if, if the actuator is broken, this can bring you any trouble). About this causing your car to run hot... if there is no vacuum the valve should be closed anyway, so that should not be a problem (unless, by some reason, is letting fresh air getting in and leaning the mixture, but I don't know if that is a possibility, I don't have any experience with them). |
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| Author: | slantfin [ Thu Oct 29, 2020 8:03 am ] |
| Post subject: | Re: Heat Riser Valve |
Quote: Quote: It has a part number 4104021
That is a EGR valvehttps://www.ebay.com/itm/1978-1981-Dodg ... _cvip=true I jetted up the carb, thinking it was running hot because too lean. It's a used 500 CFM Holley 2-barrel that I rebuilt myself. I started with #64 jets that were in the 350 CFM carb I replaced, and just went up to a 69. |
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