Cokekid 5 Posted June 8, 2020 Share Posted June 8, 2020 I am trying to figure out how to remove this Heat Riser from the exhaust manifold on a v12. I have heated the studs and the manifold but that never helped. The last thing I want to do is crack the manifold. Accepting all suggestions. Gerry Link to post Share on other sites
38ShortopConv. 26 Posted June 8, 2020 Share Posted June 8, 2020 (edited) Soak it in marvel oil. Lever it off. Tap a wedge in gap both sides, leave overnight. [Looks like there are 2 little pins to knock out of shaft if you need to take flap shaft out. Flap would be seized on too.] When I bought the 38 conv. back in 96 it had one of those and it had an annoying rattle so I removed it completely and bolted the exhaust cross over pipe up tightly to the manifold flange. No rattles, no leaks, you don't actually need it. I may have fitted a 3/8" spacer plate with hole in there. Edited June 8, 2020 by 38ShortopConv. (see edit history) 1 Link to post Share on other sites
Ray500 24 Posted June 8, 2020 Share Posted June 8, 2020 I would take a metal saw like a SawzAll and cut away the center section which appears to be cracked leaving the studs. And if you can also cut around the studs to remove as much material as possible leaving only the rusted studs in the manifold. Then it's going to take heating of the old studs to get them out. If you still have issues a good machine shop can do it for you. Link to post Share on other sites
19tom40 94 Posted June 8, 2020 Share Posted June 8, 2020 (edited) Soak the parts in a 50/50 solution of acetone and transmission oil for a few days and the heat riser should come off, by using wedges as Shortop Conv suggested. You can also try soaking it in Evaporust to remove the heat riser. The studs are a different story. The best solution that I have used on studs is to weld a nut onto the stud, let it cool and then try to remove the stud. Usually the heat from welding will break the rust bond. Edited June 9, 2020 by 19tom40 (see edit history) Link to post Share on other sites
Cokekid 5 Posted June 8, 2020 Author Share Posted June 8, 2020 Shortop Conv .Just so happens last week I had bought two bottles of Marvel Oil last week. I will give it a try. Ray500 I have never hear of this of this saw and will head out to the big box stores to see if the have one. Tom, If the Marvel Oil doesn't work I will give 50/50 solution. I will let you guy know which one worked. Gerry Link to post Share on other sites
Mssr. Bwatoe 191 Posted June 19, 2020 Share Posted June 19, 2020 (edited) Cut it , saw it what ever-- either eliminate it or get a repro----that is garbage--- the device is for winter / cold weather performance, it heats carb , mixture, carb icing etc....it literally blocks exhaust forcing it to travel up into intake chamber (which if you remove intake you will see some ports carboned up maybe even plugged........i left mine on, but removed the flapper...I drive all kinds of weather without issue.. if you eliminate it , you will need different studs to hold pipe up tight. Edited June 19, 2020 by Mssr. Bwatoe (see edit history) Link to post Share on other sites
Matt Harwood 12,199 Posted June 19, 2020 Share Posted June 19, 2020 It appears the manifold is already cracked, no? Link to post Share on other sites
38ShortopConv. 26 Posted June 19, 2020 Share Posted June 19, 2020 (edited) The flapper plate is, the manifold appears crackless? How did you make out Gerry? Edited June 19, 2020 by 38ShortopConv. (see edit history) Link to post Share on other sites
Cokekid 5 Posted June 20, 2020 Author Share Posted June 20, 2020 38ShortopConv I had it soak in Marvel oil for 3 days and was still unable to remove it. The Manifold is not cracked. Ray500, Mssr. Bwatoe I am going to attempt to cut the valve off. After that I will try what 19tom40 has suggested to remove the studs. Matt the Manifold is ok. Have been having a back problem lately and will let you guys know how I worked out. Link to post Share on other sites
38ShortopConv. 26 Posted June 21, 2020 Share Posted June 21, 2020 At the risk of breaking studs I would leave them in there. Remove flapper plate and fit 3/8" plate to compensate stud length. Link to post Share on other sites
Cokekid 5 Posted June 21, 2020 Author Share Posted June 21, 2020 38ShortopConv. There is no more risk to be taken. I had heated one stud and after letting it cool a bit I tried to remove it and it snapped clean off at the base of the Heat Riser. It looks like I'm going to have to drill the remainder and tap it. Gerry Link to post Share on other sites
38ShortopConv. 26 Posted June 22, 2020 Share Posted June 22, 2020 1%HDTHWTF%#@ Link to post Share on other sites
Cokekid 5 Posted July 9, 2020 Author Share Posted July 9, 2020 I decided to use a torch and cut the Riser off around the studs and it worked. I then heated up the studs and was able to remove them with my Easy Out Tool Thanks for all the suggestions Link to post Share on other sites
19tom40 94 Posted July 9, 2020 Share Posted July 9, 2020 Thanks for the update. It is always nice to hear a success story. Link to post Share on other sites
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