Gaskets or No Gaskets ?

furyfever

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Getting my 318 back together here…From what I remember, I had no exhaust leaks prior to disassembly…and found NO gaskets in there. What do you think guys? Should I install exhaust manifold gaskets or not? I do have a set that I remember putting on the 318 in my old 70 Fury back in the day. Removed them right away because I had an exhaust leak with them in place. I think factory used NO gaskets right? So…are gaskets only used on warped/well-used manifolds?
 
With a 360, long ago, I used exhaust manifold gaskets. NAPA MS2268 gaskets, installed with 25-30’lbs torque.
1967 Power Wagon. It was a great running truck.

My thought was that the gaskets compensated for heat warpage of the manifolds that would otherwise create small leaks that would damage the hemi-orange paint on my carefully rebuilt engine.
 
I have been running no gaskets for the last 4 summers and around 8,000 miles since my rebuild with no exhaust leaks or issues.

‘68 383
 
Mopars were designed to run without gaskets, so unless there is warpage of the exhaust manifolds, do not run any.

Dave
 
If you had aluminum heads and were using cast iron exhaust manifolds, then I'd look for some of the "wire-reinforced header gaskets" (rather than the inexpensive asbestos ones). But with cast iron heads and mainifolds, there wee NO gaskes on the OEM factory motors from Chrysler (unless they might have held a heat shield as some of the LA HP motors did).

You can put header gaskets with what you have, but no real need for it. DO install the exhaust manifold bolts, starting in the middle and working outward. DO put some thick flat washers under the bolt heads so that the mainfolds can "move" a bit. Seeking to "nail down" the manifold can result in cracks later on.

Enjoy!
CBODY67
 
From everything I've ever seen, the big blocks didn't use a gasket and the small blocks did.

From the 70 parts manual:

Small block, note gasket.
engine 1.jpg


Big Block, note no gasket shown
Engine 2.jpg
 
Personaly I Think They are a Good Idea,
Our Engines are Getting to be 40 or 50 Years Old.
And I Know I Started to get a Little leaky Around the Flange as I Got on in Years!
Regards Tony.M
 
Still wrestling with this exhaust leak problem. Thinking now it could be at connections between exhaust manifolds and crossover pipe. There was nothing in either connection when I took apart. In another thread I saw you guys talking about remflex graphite gaskets and some very good results. Perhaps this is my problem now? I put exhaust manifold gaskets in between heads and exhaust manifolds. I’m reasonably confident all is good there now…but still hearing the tick tick tick. Hate that sound! To me…the connections to the pipes look like ball and socket type that don’t use gaskets. Ive attached photos of each side…passenger side doesn’t show much but driver side does.

F5EEB8AB-44F2-4B6F-8AE2-FAA56775AD51.jpeg


886253F1-9EE3-4BC8-BDF9-B44CD1AEC489.jpeg
 
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The ticking sound most probably is from one end (usually the back bolt) of the exhaust manifold. By the time the exhaust flow gets to the ball joint, it is smoother and any ticking would be a smoother sound, usually.

IF there is sufficient erosion of the ball joint interface, either on the pipe side or manifold side, you can smooth that out with a somewhat coarse-pitch file, to knock-off the main stuff with. From there, Walker makes some viscous "sealer" that might be used to fill in the bottoms of the "small craters" before you cinch things back up again.

Shouild that fail, on the 1990s Chevy pickups, they went to a ball joint arrangement on the y-pipe/manifold interface, BUT the manifold flange was flat and the pipe had the flare on it. To bridge that gap, they used a composition doughnut gasket, sliced in half, with a metal sleeve inserted in it to slide up into the manifold flange for centering/retention. Just need to match the center diameter of the manifold to one of that-style exhaust gasket. I had to do that on my '67 Newport 383 y-pipe to get a good seal, after trying the exhaust sealer route. Drops the y-pipe about 1/4" or so due to the thicker gasket, but works great.

NAPA used to sell Walker Exhaust items in their exhaust sytem parts, so they should have a catalog with the referenced gaskets in it. A little research could yield good results, but will take a bit of leg-work to do it. You can also get into the Walker Exhaust onlike catalog, too.

Just some thoughts and experiences,
CBODY67
 
For locating noises like that, I use a couple feet of heater hose with a big funnel stuck in one end. Hold the funnel up to your ear and then move the other end of the hose around the engine & exhaust. The noise will got a lot louder when that tube is pointing straight at the source.
 
Thanks guys. I have a stethoscope tried that…and couldn’t really hear anything different. Put it at every exhaust port and gave it some gas but heard nothing. I put shop vac on “blow” and pumped into exhaust pipe sealed with a rag and tape…plugged other exhaust…went under with some soapy water and found driver side leaking a lot at mainly center ports and at ball joint connection. I got it all apart again now…getting some header gaskets in a couple days. Will clean that ball joint up real good. Upon inspection doesn’t look that bad. Other side pretty tight…thought I saw a small leak at one of the end exhaust ports. Hopefully between (better quality/thickness) header gaskets and cleaning up ball joint it should be much better. I hope??
 
From everything I've ever seen, the big blocks didn't use a gasket and the small blocks did.

From the 70 parts manual:

Small block, note gasket.
View attachment 540930

Big Block, note no gasket shown
View attachment 540931
Welp during this mornings eyesight check John (him or me) I don't see any exhaust gasket in the parts illustration, I hope he isn't confusing #58 which is the intake manifold gasket.

318.EXHAUST.GASKET.001.jpg


Now the fun part of deciphering parts manual numbers, #58 just mentions gasket but a reference to 9-50-1,

318.INTAKE.GASKET.001.jpg


onward to text page 9-16, 9-50-1 engine column shows GASKET SET, Intake Manifold (correct)

318.INTAKE.GASKET.002.jpg


but if we scroll down we see that there if a 9-50-5 GASKET, Exhaust Manifold Left, in the 318 (column)

318.EXHAUST.GASKET.002.jpg


but notice the car line of V, L which stands for (scroll to bottom of page) the Valiant & Dart line. I don't know what the w/Heat stands for, Heat Riser? Interior Heat?

318.EXHAUST.GASKET.003.jpg



So it seems to be there is a factory exhaust gasket that is not shown in any illustration's that I can find but for only the left side for some reason and on two car lines. V8 in the small car line with a smaller engine compartment means more heat? Of course this I'm sure can vary by year.

Only MA Mopar will know (or any super duper parts guy).

Your choice if you want to use gaskets, back in the old daze I never saw gaskets on the cast iron manifolds (Hemi has them, but a very rare sighting for me) only saw gaskets on headers and if I see them on the cast iron manifolds my brain thinks somethings wrong.


.
 
In this picture it doesn't appear to be much 'meat' of the Y-Pipe bell end above the flange clamp. If I remember all I saw in the old days there would be a visible substantial amount of metal above the clamp both in thickness and material.

Rust on the clamp and pipe appears that it is fairly old and maybe a poorer aftermarket quality and the clamp maybe distorted (pulled up) and not applying enough force to seal correctly.
Try another new quality Y-Pipe?

Plus also you can wiggle the Y-Pipe pipe up & down a little bit, maybe the rest of the exhaust isn't hanging right ie Midas shop non OEM hangers.


.
 
Welp during this mornings eyesight check John (him or me) I don't see any exhaust gasket in the parts illustration, I hope he isn't confusing #58 which is the intake manifold gasket.
I was mistaking that... and looking at the illustration (and in my defense LOL) it could be confusing....

Of course, my 273 in my '65 Formula S Barracuda does list an exhaust gasket/spark plug shield and the other 273 cars use an exhaust gasket.

See #99 and #100 on the '65 parts manual. (you may not be able to see these after they got reduced in size). This is probably where I got that small blocks use a gasket. They must have stopped at some point before 1970.
sm block.jpg
sm block2.jpg
sm block3.jpg
 
Welp during this mornings eyesight check John (him or me) I don't see any exhaust gasket in the parts illustration, I hope he isn't confusing #58 which is the intake manifold gasket.

View attachment 552414

Now the fun part of deciphering parts manual numbers, #58 just mentions gasket but a reference to 9-50-1,

View attachment 552413

onward to text page 9-16, 9-50-1 engine column shows GASKET SET, Intake Manifold (correct)

View attachment 552416

but if we scroll down we see that there if a 9-50-5 GASKET, Exhaust Manifold Left, in the 318 (column)

View attachment 552417

but notice the car line of V, L which stands for (scroll to bottom of page) the Valiant & Dart line. I don't know what the w/Heat stands for, Heat Riser? Interior Heat?

View attachment 552418


So it seems to be there is a factory exhaust gasket that is not shown in any illustration's that I can find but for only the left side for some reason and on two car lines. V8 in the small car line with a smaller engine compartment means more heat? Of course this I'm sure can vary by year.

Only MA Mopar will know (or any super duper parts guy).

Your choice if you want to use gaskets, back in the old daze I never saw gaskets on the cast iron manifolds (Hemi has them, but a very rare sighting for me) only saw gaskets on headers and if I see them on the cast iron manifolds my brain thinks somethings wrong.


.
While it's difficult to see, it is in the pic. #58 is the intake gasket, #34 is the exhaust manifold, and #32 is the exhaust gasket. You can see the right most port of #34 is the same as shape as the one directly left of it:

318.EXHAUST.GASKET.001.jpg
 
I never use gaskets on iron heads but always use gaskets on aluminum heads. FelPro has some great gaskets that I use from a 69 high performance 440 application. Also FelPro has excellent valve cover gaskets from that application that are made out black fiber and never leak. I haven't had a small block but every small block does have the gaskets.
 
While it's difficult to see, it is in the pic. #58 is the intake gasket, #34 is the exhaust manifold, and #32 is the exhaust gasket. You can see the right most port of #34 is the same as shape as the one directly left of it:

View attachment 552428
Oh yea there it is, I'll bet you can see it better in the original printed parts book as these .pdf scans are not all the best quality with the illustrations. Again though it appears to vary by car line and as the OP didn't post his exact application we have to do some detective work as to what car he is working on. Via his small profile pic I think I see a 1968 Fury HT but there is some mention of a 1970 and I don't remember the 1968's having the bell mouth flanges, all the ones I had were a flat flange with a gasket.

I think the key to good sealing without the gaskets is the big thick washers on the bolts & studs (don't lose them)


.
 
I ditched gasket long ago as well...been using RTV on all my exhaust pipe flange to manifold connections for over 20 years now. When I was using gaskets I might get a year out of them before they started leaking, and I tried every gasket on the market, doubling gaskets etc. I even used RTV on the small block bell end exhaust connections because the gaskets on those would start leaking to.
 
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