Exhaust...

[1968 Ford F-100]

Hello,
I have a 1969 Ford F-100 with a 360 FE and C6 Auto Trans. It is 2wd and I am having a problem with the exhaust manifold to pipe gaskets(donuts). They don't want to stay sealed for more than a few days. I had the original exhast manifods on it and the cone surface was eaten up pretty bad. So I purchased a brand new set of manifolds. It was better but they are still giving me issues. I have new Studs and New donuts. I have tried both the steel donuts as well as the composite. I am stumped. I am strongly leaning toward getting a set of shorty headers. I like Sanderson headers but I am not sure which ones will work for my application. I don't want any issues. Maybe I am doing something wrong when installing the donuts. I always make sure to tighten them equally on both sides. Can anyone offer some insight? Either on the donut problem or a set of shorty headers that will work with my truck?

P.S. If this is the wrong area to post this I apologize. Also, this site is the best hands down!

Sam

[71PA_Highboy]

There should be a steel sleeve that protects the donuts from the exhaust ... the donuts just seal the outside.

If you don't have that sleeve they will burn out and leak.

hth,

eric

[1968 Ford F-100]

71PA_Highboy.....did these come from the factory this way? If so, have you seen them available? or know where I can get one? Thanks.

[71PA_Highboy]

The exhaust shop has always put them in.... They are just pieces of exhaust pipe inserted into the pipe...

Eric

[1968 Ford F-100]

Thanks 71PA. I will ask around at a exhaust shop. Wouldn't by chance know what the size is would you? Thanks again.

[1968 Ford F-100]

Also, I am under the impression that the sleeve is only needed for when using fiber donut gaskets and not a steel donut gaskets. The sleeve keeps the fiber gasket in tact and from crushing...basically supporting it and protecting the gasket from the heat. I beleive the steel gaskets would not fail from heat and I would not need a sleeve am I correct? I am also under the impression that from the factory the y-pipe came with a insert that was part of the pipe itself. I may be wrong. If anyone can elaborate..please do. Thanks.

[71PA_Highboy]

I would say your impressions are correct, but...

Any time you subject a substance to heat/pressure that exceeds its yield, it will fail. You KNOW the steel insert won't fail, so why risk it hoping the metal insert won't fail (I am not sure what they are made of, but I think it is lead and a binding fiber).
If you are talking about the ones that appear to be solid, I would always assume they are going to leak without some type of gasketing as the manifolds are rarely smooth. Did you 'lap' the manifold the way you do valves to ensure a constant/complete seal?

As for the factory Y pipe, you are correct.




Eric

[1968 Ford F-100]

Yes, I was talking about the solid type donut. I have new manifolds on the truck. The original manifolds had really bad corrosion where the donut contacts the manifold. So I bought a new set and i keep burning out the composite donuts. I have a new set of solid steel donuts to install. I bought these since my original steel donuts were warped and wouln't sit in the cup of the manifold without rocking. So, I figured the old ones would leak. I am sure your asking if I lapped the head to manifold surface to make sure there are no leaks there. I did so on the originals as well as the new ones for good measure. I also used gaskets there also...eventhough I've heard you don't need to if the head and manifolds have been machined flat.

Thanks for confirming for me. Learn something new every day.

[1968 Ford F-100]

Oops...just got what you were saying about "lapping like you do valves"....duh...I missed that one. The new manifold cup is nice and round and smooth. My old steel donuts are warped. I have new ones. I'll try those I suppose. If they don't work i'll have to get 2 sleeves. Tonight I have to tear down a truck for parts so I'll get to it in the next couple days....if not the weekend for sure. My truck sounds like a junker with the leaks. Bothers me since I just rebuilt the engine and whatnot. I'll keep plugging away. Thanks again.

[fomocoguy]

Also check to make sure the system is hung properly. If it doesn't have as much support as it should and the pipe is bouncing up and down as you drive it may be smashing the gaskets enough to make them leak, and as soon as a small leak is developed that is where it will begin to burn out. Just my

[1968 Ford F-100]

Thanks Fomocoguy. The system is really really secure. I swear you could almost support the truck. Anyone had any luck with Sanderson Headers? Looking for block hugger shorty. Anyone have any input? Thanks.

[1968 Ford F-100]

Ok, so I contacted Sanderson and spoke with someone about a set of headers for my application. They recomended the FF427 for 53 & up F-100. They said if they didn't fit that I could return them for a full refund minus the shipping. I figured I'd try these and see if they bolt up and aren't too long. If they didn't all I would be out is the gaskets and shipping. Also, said I could return them and exchange them for a different set....say the F390 or the FF391 sets. I think I am going to give them a try. I've never had a set from them but other guys on here have said they have had good luck with that brand. Would like to hear from someone who had a similar setup as I have. Thanks.

http://www.sandersonheaders.com/popup_image.php?pID=88

[seattle67]

I put a set of Sandersons on a street rod I built a few years back (chevy, cough cough ) and was impressed with the quality.

[rubiranch]

"I plan to start procastinating immediately"

Why not start tomorrow?