I have a really bad exhaust leak on the driver side where the exhaust manifold connects to the pipe going down. I looked in my service manual and they show a exhaust valve of some sort. This is missing of course. I am familiar with the old donut looking gasket that would fit there, but my manual shows just flat gasket. Is anyone familiar with this setup? Can I just replace with a new flat gasket without any problems ? Thank you for your time. 20210926_193904[/url
Not being familiar with how the Jeeps attached their pipes to the Buick manifolds and just going by the picture that you posted, I can tell you that Buick used a valve with a radiused attachment point on their vehicles. Your picture shows a flat surface both at the manifold and at the pipe/valve attachment point. It could be that since you mention that the valve is missing when the exhaust pipe was attached directly to the manifold there was a gap that the gaskets could not make up for. In any case, you may just need a new gasket or two. I make a substitute for our Buick's valve but it has the radiused flange as mentioned. Somewhere on this thread is a gasket that fits the Buick 350 manifold bolt pattern, I don't know that the Jeep Pattern is the same. Heat riser valve delete * UPDATED 6/28/2020* | V8buick.com Good luck!
I just read the link about the valve and that makes COMPLETE sense. I am sure it is the same as the Buicks as the engine is a 350. The previous owner was NOT mechanically inclined and it seems everything he touched is just a mess. I am slowly getting each thing fixed either back to original or upgraded. I will buy one of those deletes as we have mostly warm weather here at the Lake of the Ozarks. . Thanks for the help. I really appreciate it more than I can express.
The Buicks that used the heat riser valve had a flat surface from the valve to the manifold, the head pipe end of the heat riser had a tapered seat...... no gasket
So what does everyone do when they change out their entire exhaust system ? Do the exhaust shops have a different connector to match the flat portion of the exhaust manifold ? OR do they flair the pipe like the original and use an adapter like Hectors ? I am going to try to unbolt my pipe and get some pics to be sure this is the same, but it sounds like it is. Just looking for options. i am not thrilled with the muffler that is on the Jeep right now, but can't find a Walker Quiet flow for 2" pipes. I might swap the entire system out, but want to be sure of how to connect it to the manifolds. I don't need or want headers.
It looks like Jeep (i.e. Kaiser-Willys) used a different exhaust manifold than Buick & if so Hector's adapter wouldn't work but based on the picture from the shop manual (I think I still have mine from my '70 Wagoneer), it would be easy to make one. Just need a small piece of the correct thickness steel & 2 flat gaskets. Cut it into the correct shape (optional really) and add the 2 bolt holes & exhaust hole. Doable by hand but certainly much easier w/a a laser, water jet, plasma, or CNC mill.
I wonder if his exhaust has enough give in the system to just bolt the 2 existing halves together again with a new gasket (probably how it is now?) Otherwise I think even easier in terms of fab would be to measure the bolt spacing, then buy a universal 2 bolt flange to use as a spacer. Something like this: https://www.summitracing.com/parts/stw-fl2002 They make a bunch of different ones with different bolt patterns. Vibrant Performance also sells them.
I think that's his problem - The PO just took out the valve and bolted the exhaust up as you suggested. Not enough give and now there's a leak. Yes! Exactly what I had in mind. Didn't know they were available.
Sorry for delay. It takes me a while to crawl under the Jeep and actually do anything. I decided to unbolt the driver side to see what each part looked like. As I was under the Jeep, I looked over to the PASSENGER side and see the heater valve. LOL, ah, I wish I was 20 years younger and had my head working better. So the valve is NOT on the driver side. So I unbolted the driver side. I noticed the exhaust manifold has a rounded surface. not a flat one as shown in my manual. Yes, the engine is original. It was owned by one family since new. The pipe side was flared out to cover over the exhaust manifold. The only thing missing.....was some kind of gasket. A flat gasket wouldn't work as it needs a donut type gasket from what I remember in my younger years on vehicles I had. So I measured the distance of the exhaust manifold hole at 1.90 with my micrometer and then measured the width of the flared end of the pipe with was 2.65 and went looking for a donut. I found a Nickson 31387 at O'Reilly Auto parts. It is 1 7/8" in the middle and about 15/32" thick. I crawled back under the Jeep and installed this between the two pieces. It sealed up pretty good from the picture. I do not have the radiator or battery in the Jeep right now to test, but I feel confident this will seal the exhaust at least until I decide if I am pulling the engine for a rebuild or driving it for a while. Thanks for all the help. I love to learn about this awesome Buick and Jeep Wagoneer. Even if my craniotomy slows me down and keep me guessing alot. You folks are inspiring to us old folks. Driver side Buick 350 built in Sept 1969 on 70 Wagoneer
That type of head pipe flange and corresponding flange on the manifold doesn’t use a gasket, BUT I have done the same thing to seal mine when I had manifolds
I think the only thing I would do different is replace those threaded rods on both ends with just some stainless bolts with lock washers.
Also use anti-seize, it'll be much easier to remove again if you need to! One trick you can use to check for exhaust leaks without running the engine, if you have a shop-vac, put it in blow mode and duct tape the hose to your tail pipe. Run the vacuum and any leaks should be easily felt with your hand. You can also spray the joint with soapy water if in a hard to reach area! So much more pleasant than crawling under a hot running car.
