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JeepMonkey 06-13-2013 02:40 PM

Exhaust Manifold
 
1 Attachment(s)
Today my new exhaust manifold came in via fed ex. While examining the contents of the delivery, I noticed the gasket that came with the exhaust manifold was not an exact match. from this, I decided that it must be a dual purpose gasket designed for both the exhaust and intake manifold. My question is:
A: am I correct? And

B: is this part necessary or is it likely that I can reuse whatever gasket is already installed?

Note: I realize this may be a dumb question but every step in this jeep adventure is new to me!


Attachment 637604

dirtdudeaz 06-13-2013 03:03 PM

The exhaust and intake manifolds are on the same area. They share some of the same studs or bolts to hold eachother together and to the engine. The kit is correct.

jeepwhore 06-13-2013 03:36 PM

Yes, it is a dual gasket for both intake and exhaust manifolds and yes you'd be wise to use a new gasket. As for if the one you have is superior to using two individual gaskets, I'm not one to say but i have seen others ask which is better......

walkerhoundvm 06-13-2013 03:39 PM

I just used that one, even though the kit I bought came with that one and a separate one for the intake. All is well after a year.

And you're in for some fun. Replacing the intake/exhaust manifolds is just about the most curse/blood/tear/alcoholism inducing project I've had to do (twice) on my CJ to date.

Nereussailor 06-13-2013 03:41 PM

A yes, B no. Always use a new gasket. Once it crushes under torque it will seal. It usually won't hold up when you re-torque it.

JeepMonkey 06-13-2013 03:45 PM

Quote:

Originally Posted by walkerhoundvm
I just used that one, even though the kit I bought came with that one and a separate one for the intake. All is well after a year.

And you're in for some fun. Replacing the intake/exhaust manifolds is just about the most curse/blood/tear/alcoholism inducing project I've had to do (twice) on my CJ to date.

Yaaaay! You really know how to make a grown man cry, don't you?

Thanks for all the input. My gut told me the same as you all have advised but I wanted to verify before tackling the project.

Now.... Where did I put the emergency stash of beer?

LumpyGrits 06-13-2013 04:48 PM

USE IT :thumbsup:
Use copper anti-seize on those mounting bolts/nuts too.
LG

keith460 06-14-2013 04:38 AM

FYI,

Your model year Jeep did not originally have an exhaust gasket installed from the factory. There is only one for the intake manifold so that no vacuum leaks occur. You can see the difference in the thickness of the mounting tangs between the intake and exhaust manifolds. The exhaust manifold will have thicker tangs than the intake manifolds. The mounting bolts will have Bell Washers that make contact with the tangs and when a intake gasket it used only, the tangs will be flush between the two.

If you are going to use the gaskets, two MUST be used. One for the intake and another for the exhaust/intake ports like you show in your first post.

Typically, the exhaust manifold is ground perfectly flat just like the cylinder head so no gasket is needed between the two. Both the cylinder head and exhaust manifold are made of cast iron so the both expand and contract at the same rate and is another reason why no gasket is necessary. If you purchased or are using a header pipe out of steel or stainless, then yes, a gasket must be used.

I run my 84' 258 engine without the exhaust gasket, just as it came from the factory that way, and have no leaks, both vacuum and exhaust wise.

http://i123.photobucket.com/albums/o...takegasket.jpg

walkerhoundvm 06-14-2013 06:39 AM

No offense, Keith, but I'm not going back in there again to fix it. I've noticed no vacuum leaks with my manifold in the past year, FWIW. It could be that these gaskets are thick enough to accomodate for the differences in thickness :shrug:

Your rationale sounds correct, though.

capt205 06-14-2013 07:16 AM

I recently had the head off my '83 258. It did not have a gasket on the exhaust manifold. When I put it back together, I used the FelPro dual gasket from NAPA, and it works just fine...no leaks.

JeepMonkey 06-14-2013 08:10 AM

Quote:

Originally Posted by keith460
FYI,

Your model year Jeep did not originally have an exhaust gasket installed from the factory. There is only one for the intake manifold so that no vacuum leaks occur. You can see the difference in the thickness of the mounting tangs between the intake and exhaust manifolds. The exhaust manifold will have thicker tangs than the intake manifolds. The mounting bolts will have Bell Washers that make contact with the tangs and when a intake gasket it used only, the tangs will be flush between the two.

If you are going to use the gaskets, two MUST be used. One for the intake and another for the exhaust/intake ports like you show in your first post.

Typically, the exhaust manifold is ground perfectly flat just like the cylinder head so no gasket is needed between the two. Both the cylinder head and exhaust manifold are made of cast iron so the both expand and contract at the same rate and is another reason why no gasket is necessary. If you purchased or are using a header pipe out of steel or stainless, then yes, a gasket must be used.

I run my 84' 258 engine without the exhaust gasket, just as it came from the factory that way, and have no leaks, both vacuum and exhaust wise.



Keith,
Your Jeep is AMAZING! I remember looking thru your build thread and seeing when you brought it out of the garage. If memory serves me well, I believe you were wearing white or latex gloves. Wow is an understatement.

Stupid question number 2 and 3

2. WTH is a "Tang"?

3. What does a bell washer look like? I want to make sure I have all the proper hardware.

I am going back with an OE exhaust manifold so your logic applies. If that is the correct way, then you may have just save me a lot of work from not having to remove the intake manifold.

keith460 06-14-2013 07:03 PM

A Tang is country isn't it? No wait, that's twang!

An orange drink the astronauts took with them in space?

It would be the little piece of casting on both the intake and exhaust manifolds that the Bell washers make contact with to hold them to the cylinder head. Might be called something else like an ear, but I don't know.

http://i123.photobucket.com/albums/o...reakdown21.jpg

Cutlass327 06-16-2013 12:13 PM

I found it easier to install studs in place of the bolts, then just slide the manifolds onto them. I got the studs from a local bolt and nut house. Lots of Never-Seize, 2 gaskets, and reused the bell washers on the studs. Also use stover nuts, to help keep them from backing off. I still go over them every few months (I drive it daily) and re-snug all the nuts, as they do back off a little. I went this route with the studs after cross-threading a bolt and snapping off the rear of my original manifold trying to simply replace the gasket.

If you have the bolt-together manifolds (mine does, it's a 78) make sure you loosen the two manifolds from each other a bit to allow them to seat to the engine properly. I didn't, figuring I haven't moved them, they should just align right up, but they didn't. They must have warped just enough to not go back on smoothly, which led to the broken manifold and also having to Helicoil the rear-most bolt hole in the head.

JeepMonkey 06-17-2013 03:26 PM

Started dismantling everything yesterday and found that I have gaskets on the existing exhaust manifold and the second gasket on the intake.

Sounds to me like there isn't a definitive answer on whether or not it is best to use a gasket on the exhaust manifold. There are a lot of good results both ways.

Regardless, I have to buy a gasket for my intake manifold since my new exhaust manifold did not come with both. Decisions, decisions.

Not sure what I will do because I can already tell this is not a job I want to do again. Hell, I'm not exactly sure the best way to remove the power steering pump. That should let you know how new I am to mechanic work.

walkerhoundvm 06-17-2013 05:22 PM

You shouldn't have to remove the power steering pump. At least I didn't.

Sheesh, you are new ;)


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