MoparFins

Techical Discussions => General Tech => Topic started by: Robert Rottman on September 01, 2008, 04:04:34 PM

Title: Stuck (closed) heat riser valve??
Post by: Robert Rottman on September 01, 2008, 04:04:34 PM
Hi Guys....I just finshed cleaning/painting/reinstalling my intake manifold on my 70 Fury III 318. The crossover exhaust passageway was completely plugged up with carbon. I painted the intake manifold with POR-15 engine enamel! After my FIRST start/run of the motor, I noticed the fresh paint is burning already right above where the passageway is on both sides...ALSO....I painted the exhaust manifolds with HIGH HEAT paint while I is was in there....I noticed on the passenger side (with the heat riser valve) the paint is already flaking off(http://www.moparfins.com/forum/smileys/smiley5.gif)....I can't believe it!!(http://www.moparfins.com/forum/smileys/smiley19.gif) Is it possible the heat riser valve is stuck/rusted in the closed position? Do I have to remove the exhaust manifold to check this?? Check out the photos...Why is it...when you think you're done....you're not?(http://www.moparfins.com/forum/smileys/smiley7.gif) click on photos below to enlarge.
 
 
furyfever2008-09-01 21:16:17
Title: Stuck (closed) heat riser valve??
Post by: Steve on September 01, 2008, 04:43:53 PM
You're fine.
 
If the heat riser were stuck closed, you would be having performance issues and the intake would be all black.
 
You need some heat in the intake to open the choke.  There is going to be some heat crossing over by default anyway.  The Heat Riser Valve just being there is offering some resistance.  That is what you are seeing burning the paint.
 
Typical 318.  Blocked cross over.  The paint is buring because you opened it up too.
 
Is the heat riser moving???
Title: Stuck (closed) heat riser valve??
Post by: Robert Rottman on September 01, 2008, 05:41:30 PM
Yeah....but...but...but...The 318 in my 69 which was painted three + years ago isn't doing this....The paint on the intake is still very nice....like the day it was painted....and the exhaust manifolds are still pretty decent too. Why on earth after starting and running 1 time would this happen?? I'll have to check to see if I can turn the heat riser valve tomorrow. I should be able to grab the round steel piece and turn it right?? I had my 69's exhaust manifold apart 3 years ago and removed the steel flap inside....I just put the shaft back in without it (so it wouldn't leak) . I have a feeling I might have to do this again...Oh yeah...by the way the motor runs well...I took it out on the road and floored it a few times tonight....A lot of soot blew out the tail...A lot of smog in the rear view mirror(http://www.moparfins.com/forum/smileys/smiley36.gif)
 
Thanks, Bob  
Title: Stuck (closed) heat riser valve??
Post by: Steve on September 01, 2008, 05:47:01 PM
Good question.  is it the same paint on the 69?  Maybe the one on the 69 is stuck open and this one isn't?
 
You should be able to grap the counter weight and twist it.  If it moves and is stiff, shoot some pb blaster on it and get it freed up.  Once it's operating properly, the story is over.  Just make that a regular maintainence item.  Spray it up when you park it for the winter.
 
Maybe the valve is partially stuck closed. Without dropping the pipe, it's unknown.  Off the top of my head, I don't remmeber which way the counter weight should be for it to be open.
 
I know I had that on my 360 with a properly working riser valve. . . .
Title: Stuck (closed) heat riser valve??
Post by: Robert Rottman on September 01, 2008, 06:05:37 PM
Thanks for the insight Polaraco...I just went out there and the counterweight is indeed frozen/stuck. Can't budge it either way. I banged on both sides with a ball pean hammer....the front side shaft and rear side counter weight and could'nt get it to budge. It's either stuck open or closed or part ways like you said. Man.....I don't want to remove it.....There's no exhaust leak over there...I wish I could free it up in place...I'd hate to break off a bolt too!! There's 6 holding it on the head...plus two holding it to the crossover pipe..Fun Fun Fun...Why can't I remember this when I start eyeing another C or Fin car....(http://www.moparfins.com/forum/smileys/smiley12.gif)
Title: Stuck (closed) heat riser valve??
Post by: Leaburn Patey on September 02, 2008, 02:25:08 AM
Luckily,Ma was smart enough to use nut and bolts on the exhaust manifold flanges--unlike Chevy and Ford where they used studs.
On Mopars,if they do not come easy,break them off and use new ones-simple.
Should you break a stud in the head removing the manifold,that can be tricky.
If there is enough meat left of the broken stud,weld a nut onto it and then remove it. 
If it is flush with the head,time to get the drill and tap set.....

Title: Stuck (closed) heat riser valve??
Post by: Robert Rottman on September 02, 2008, 05:04:47 AM
(http://i36.photobucket.com/albums/e45/bigredfury/th_S5001268.jpg) (http://i36.photobucket.com/albums/e45/bigredfury/S5001268.jpg)

A leaky valve cover gasket proved to be an asset here. All 6 nuts/bolts came off very nicely. And the two holding the crossover were actually loose! Anyways for what it's worth to you guys in the future....It looks like the heat riser valve is 75-80% closed....frozen in place. I should have known to check this as soon as I brought the car home two+ years ago. I think this has something to do with the intake crossover being full of carbon too! Less flow from side to side....carbon built up in intake crossover instead of going out the tail(http://www.moparfins.com/forum/smileys/smiley2.gif) Maybe?? Thanks for your replies Polaraco and Cbarge...

Bob
Title: Stuck (closed) heat riser valve??
Post by: Steve on September 02, 2008, 05:16:17 AM
I forgot to mention
 
When a working heat riser is parked for long periods of time, it can get stuck closed.  So it being partially closed let enough exhaust to buz by not to stall the car.  Get that sucker working and then see what happens with the performance
Title: Stuck (closed) heat riser valve??
Post by: Herman on September 02, 2008, 07:34:29 AM
I say ditch the logs, put some headers on it and enjoy the newfound power... (http://www.moparfins.com/forum/smileys/smiley2.gif)



Title: Stuck (closed) heat riser valve??
Post by: Snotty on September 02, 2008, 10:08:52 AM
Bob, I always cut these valves off and have the holes welded closed.  No more leaks, closings, or rattling noises.  Of course I live in a very warm climate.  I don't know where you live, but unless it gets really cold in the winter, and you do drive it then, I would suggest removing the valve and being done with it.
 
It will not harm your motor at all to not have it there.
 
I also like the idea of headers, but I think you want to keep your car stock, yes?
Title: Stuck (closed) heat riser valve??
Post by: Robert Rottman on September 02, 2008, 04:32:31 PM
I had the day off today. I drilled through the shaft on both sides of the valve, kept increasing drill size until the shaft broke....had a hard time getting the remainder of the shaft out of the bushings but managed to do so....Used a long bolt to plug up the holes and re-attached the counter balance so it looks somewhat original. Cleaned and painted with high heat paint....No more valve to get in the way now. I called the auto store in time to get a set of exhaust manifold gaskets and got everything back together by the end of the day. I'm ready to roll....I'll get an inspection tomorrow and have my Fury driver for the fall now.  
 

Title: Stuck (closed) heat riser valve??
Post by: Steve on September 02, 2008, 04:52:01 PM
Robert?  The car looks great (http://www.moparfins.com/forum/smileys/smiley32.gif)(http://www.moparfins.com/forum/smileys/smiley32.gif)(http://www.moparfins.com/forum/smileys/smiley32.gif)(http://www.moparfins.com/forum/smileys/smiley32.gif)
 
Glad it worked out. 
Title: Stuck (closed) heat riser valve??
Post by: Robert Rottman on September 03, 2008, 05:26:07 AM
Yes...Robert or Bob works....Thanks Steve? Polaraco...The car came out of Long Island originally....spent some time in Connecticut and now resides in upstate NY...It needs the minimum...both sides painted....may go for a full paintjob in the near future. If I do, it will get a color change....the lighter green Ma offered that year.. We'll see. It deserves some attention because it's a very solid car and of course it's C!!...Thanks..Bob
Title: Stuck (closed) heat riser valve??
Post by: Leaburn Patey on September 03, 2008, 03:50:55 PM
(http://www.moparfins.com/forum/smileys/smiley20.gif)
Title: Stuck (closed) heat riser valve??
Post by: Robert Rottman on September 04, 2008, 12:37:41 AM
Well....I took her down to the local garage for the inspection yesterday afternoon. When I went to start it up....just what I was afraid of before I took it apart....Exhaust leak!! I HATE exhaust leaks.(http://www.moparfins.com/forum/smileys/smiley7.gif) Makes a car sound like a big pile of crap ready for the scrap yard...The guy at the shop said that the exhaust manifold gaskets are worthless. He said that He always just bolts them on...metal to metal. I always thought a gasket must go in between motor/exhaust manifold. I never heard this before. Has anyone else?? When I removed it, I did find nothing in between(http://www.moparfins.com/forum/smileys/smiley3.gif)....When I started her up I was not only mad...but My first thought was that it is leaking from the exhaust manifold/crossover connection. Perhaps I have that connection misaligned a bit??? Maybe I need to loosen both sides of the crossover and then retighten?? Then I'll get a leak over on the driver side too...(I can see it coming)...What have you guys done in the past? Is there a proper sequence of reassembly here? It'll have to wait though, because I'm on to another project...The shed needs attention while the nice weather is here... furyfever2008-09-04 05:47:22
Title: Stuck (closed) heat riser valve??
Post by: Leaburn Patey on September 04, 2008, 07:22:58 AM
Metal on metal,Bob.
That's the way Ma did it when new.
I always had my logs planed to ensure a good seal.
Gaskets can burn out.
Title: Stuck (closed) heat riser valve??
Post by: Steve on September 04, 2008, 09:07:30 AM
Gaskets can only burn out if there is a leak
Title: Stuck (closed) heat riser valve??
Post by: Snotty on September 04, 2008, 06:20:43 PM
Yes, from the factory there were no gaskets.  I always use them and never have leaks.  Did you torque them down to the correct spec?
Title: Stuck (closed) heat riser valve??
Post by: Stitcherbob on September 04, 2008, 06:34:47 PM
spray a little high temp copper spray on 'em and let dry.....worked on even the most spindly long Packard and Buick straight eight manifolds.

Re-torque after a few heat cycles....


Title: Stuck (closed) heat riser valve??
Post by: Robert Rottman on September 09, 2008, 05:29:33 AM
Well...I did remove the exhaust man. gaskets....back to metal on metal now....not sure if they were causing a leak or not, because I still have an exhaust leak where the ex. man. meets the crossover pipe (I put my hand down in there and felt it). I'm thinking I have to loosen the crossover where it meets the muffler pipe now...then reattach/tighten the crossover to the exhaust manifold. Is this the proper method to get good alignment with the two?? There's no donut there...Are there any other tricks to get rid of a leak here??
 
Bob
Title: Stuck (closed) heat riser valve??
Post by: Leaburn Patey on September 09, 2008, 01:46:52 PM
It is possible that the flanges on the crossover are bent causing a leak.
Two ways fixing it.
1.Remove crossover,heat up flanges and hammer them flat.
Clean the gasket surfaces area.Install new falnge gaskets.
Re-install and make sure to tighten up the bolts evenly.
Do not tighten one up all the way and then do the other--you are guaranteed to bend the flange  .
Or
2. Drop the crossover down enough to use a couple flange gaskets and lots of Ultra Copper .
I always re-tighten the flanges after runing the engine a bit.(Ouch! Ouch OOOhh Ouch!)
Title: Stuck (closed) heat riser valve??
Post by: fury fan on September 10, 2008, 09:40:02 AM
Don't all the smallblocks have the swivel-cup flange on the manifolds and headpipes, though?  I've not seen every smallblock, but every smallblock I've seen was that way...

It's possible that there is a dent or flaw on the cup of the headpipe, if so, hammer it back as best you can.  Goop it up with hi-temp copper RTV and say a prayer. 
 
If that doesn't work, try my next trick:
Strip some lengths of copper wire and twist them together, make a circle the size of the cup, lightly solder the ends together (you don't want to make a large hard spot, just enough to hold the ends together while you place this new 'gasket'), goop it up with the copper RTV, and assemble.  The theory is that the wire strands will mash as necessary to meet the irregular surfaces.  You'll have to use some judgment for wire gauge, how many strands, etc.
 
I did this on a warped flat-flange pipe that blew gaskets monthly.  This trick lasted over a year.
 
fury fan2008-09-10 14:44:25
Title: Stuck (closed) heat riser valve??
Post by: Robert Rottman on September 10, 2008, 11:10:44 AM
Yes Furyfan you are right....I didn't understand what Cbarge was saying....He has big blocks so I'm sure that's why...The best way I can describe this setup is that the crossover has a cup on it that fits onto the exhaust manifold and it has a taper.....theres a flange which is just a flat plate with 3 holes in it...a big one in the center for the crossover pipe (outside diameter) and two small holes on either side for the nuts and bolts. No donut. When I undid the two bolts the flange fell all the way down the crossover pipe so it's fairly loose on the pipe. You're right, I better remove it again and make sure there is no rust/junk on that taper on the exh. man. and that the cup on the pipe is nice and round/clean. I thought I did so...but perhaps I missed something. Since I wrote my last reply I have noticed some small holes in the exhaust manifold...they look like intentional factory relief holes? I am feeling leaks from these holes too. I'd like to tap them and screw some small bolts into them while I have it out...again(http://www.moparfins.com/forum/smileys/smiley5.gif)..I can't imagine why Ma put those in there...I'll have to look at the other side and see if that one has them too. These holes are probably only 1/8-3/16" in dia....down low on both sides of the heat riser valve. furyfever2008-09-10 16:12:22
Title: Stuck (closed) heat riser valve??
Post by: Matt Aker on September 10, 2008, 11:14:06 AM
Is the engine original to the car Bob?
Title: Stuck (closed) heat riser valve??
Post by: Robert Rottman on September 10, 2008, 03:23:02 PM
As far as I know Matt...I've never read the numbers to see if they match. Does something sound fishy?? I don't know where to look for the numbers on the motor and what I should be comparing them to. If you fill me in, I'll look into it. Thanks, Bob
Title: Stuck (closed) heat riser valve??
Post by: Matt Aker on September 10, 2008, 03:38:24 PM
The reason I asked is because of the leaking open holes you described in the manifolds.
 
From my experience those would be from emissions tubes, and perhaps there has been a manifold swap at some point.  Maybe the logs have been swapped and they're newer than the car's engine.  It's not uncommon for those "ports" to be plugged with JB-weld or another equivalent when the manifold isn't totally correct.
 
Your idea of tapping and plugging is the way to go if this is the case with this log!

Title: Stuck (closed) heat riser valve??
Post by: Stitcherbob on September 10, 2008, 06:37:08 PM
Don't forget guys....silicone sealers (which I personally hate) only seal when assembled AFTER they had a chance to set up into a rubbery gasket. Tighten them when wet and all you get is metal to metal with silicone squished out all over.....

Title: Stuck (closed) heat riser valve??
Post by: Robert Rottman on September 10, 2008, 06:37:32 PM
(http://i36.photobucket.com/albums/e45/bigredfury/th_S5001299.jpg) (http://i36.photobucket.com/albums/e45/bigredfury/S5001299.jpg)
Click on photos to enlarge...You can see the small holes one on each side of the heat riser valve. JB Weld will hold up to the heat? I have some and can try patching these holes up if I know it will last.  Has anyone ever seen these holes in their logs? Exhaust is streaming out these holes when the engine is running. I'm thinking that's what I'm feeling when I put my hand down there. Since I removed the exhaust manifold gaskets the exhaust leak is much quieter now....(I now have "metal to metal") but I can still hear a small leak..perhaps it's from these holes??
Bob
Title: Stuck (closed) heat riser valve??
Post by: fury fan on September 11, 2008, 02:43:56 AM
I've never used any JB Weld stuff on a manifold so I have no opinion there.
 
I would drill/tap the holes and install allen-head setscrews with some hi-temp RTV.  If you dont make threads all teh way down you could tighten the setscrew against the end of the threads, effectively giving it some interference-fit at the bottom to help hold it in place. 
Title: Stuck (closed) heat riser valve??
Post by: Stitcherbob on September 11, 2008, 06:52:33 AM
Those are the oiling holes for the shaft. The JB weld probably won't hold up, but Lab Metal putty will. It's one part and comes in 2 versions. The second one is for really high heat situations. http://www.alvinproducts.com/Products/Products.asp?ID=2 (http://www.alvinproducts.com/Products/Products.asp?ID=2)
As a cheaper alternative, NAPA and other stores sell a muffler patching putty in a tube. It might work.....