View Full Version : 95 C350 Exhaust Build

03-27-2014, 10:39 PM
I'm going to try to document this process and the parts used for anyone that might be interested. I'm hoping for some slight gains in power and mpg with the work and fixing the exhaust manifold leak. With a best of about 10.5 city and 13.5 hwy. I'm not sure there's much to gain but time will tell. I'll list any other mods that might contribute to the mpgs. And of course I will take pictures as I go, but this is not rocket science or as cool as a diesel swap.

Because I want this to last I decided to spend the extra money for stainless pipes and mig wire. Just trying to figure out if I have to run gas with this wire even though it has flux. I haven't run gas with my welder yet but it should help my welds look better.

Starting with a cylinder head bolt hole repair with a helicoil and brazing to build back the flange for the gasket. I sourced all the parts from Amazon because they seemed to have the best prices.

Doug Thorley headers
EDIT - 2.5" to 3" Don't need this part. Product data was incorrect the headers outlet pipe is 3".
3" pipe cut to fit
3" in 3" out Flowtech Warlock Muffler
3" single in Y to 3" dual out
4" 180* bend and 4' of straight pipe for crossing from pass side to drivers in front of the tank and random fitting
(2) Magnaflow 3" mandrel bent exhaust pipes 15003 (one to be cut and angles mirrored for a drivers side exit
Finishing it off with 4" stainless 12" long rolled end tips

03-28-2014, 08:25 AM
I always wanted to do stainless. Just haven't gotten around to it yet.

If the wire has flux you do not need gas. It won't be the prettiest welds, but considering what it is, not too many people will every see it.
Pretty doesn't mean good weld either so go for it.

03-29-2014, 08:58 PM
Correction. The wire I bought doesn't have flux. Time to rent a tank of gas. Hoping get the thread repair and brazing done next weekend or sooner. Probably should double check the layout and lengths to make sure I have enough pipe.

03-30-2014, 09:35 AM
You can buy disposale tanks from places like harbor freight, also watch craigslist. Every now and then you can get a deal on a tank.

03-31-2014, 08:22 PM
Did you see this one? Linky (http://www.fourdoorbronco.com/board/showthread.php?4551-Headers-on-the-94&highlight=exhaust)

04-01-2014, 12:20 PM
I hadn't. Thank you Bob, I hope I don't have to modify the header Y pipe since mines an automatic.

I figure this setup will be mostly just off the shelf parts that are easy for anyone to order and take to a shop for install. My local shop wanted $100 for the stainless 3" 180* U that I bought for about $30.

04-01-2014, 07:38 PM
Yeah we do a lot of exhaust pieces off of Amazon too.
Ebay isn't bad because you can see peoples reviews and shipping has gotten better, but last time I tried to combine shipping the seller would not let me. I wasn't looking for a free bee, I just wanted reduced shipping for one or two boxes.

If you can get them to respond there is a couple sellers on Amazon that will do their best to get you anything you need and shipping is fast.

04-03-2014, 12:08 PM
Did a little prep work last night. Hoping to start tonight or tomorrow night on the thread repair and headers. Sprayed nuts and bolts with penatrating oil. Verifyied I have enough pipe, should have about 1' left over. Double checked the pipe path I want to use and moved the rear axle breather tube on the frame rail to make more clearance for the drivers side. Completely forgot about the air injection into the cat..... I noticed the muffler and cat have small leaks and since its emissions exempt I was planning to just remove the cat. I want to leave the injection tube in case I ever want to add a cat back in. I can't find good info on what I can do and not cause drivability problems. Cap it, leave it open, etc..... My understanding is it adds air to help the catalyst process in the cat which helps prevent clogging. Since its a speed density there is O2 before the cat. Thinking about just welding the tube into the new pipe so I can just add a cat downstream later if needed or desired. I'm a little concerned it may be louder than my wife likes and a cat should help with that if its a problem.

Any advice?

04-03-2014, 01:23 PM
Cat will usually help make it quieter. But you have a full tail pipe to get the noise away from you so you probably won't notice.

You can leave the tube just hanging there and drive it after, but I am sure that is just an air pump and removing it will not cause drive ability problems at all. So remove it, cap it, leave it open. Doesn't matter.
Eventually remove the pump and put a shorter belt on.

04-06-2014, 04:34 PM
I'm really disappointed in progress right now and got a quote from a really good exhaust guy of $450 to do all the labor. I'm not one to give up but without a spare vehicle I'm thinking about throwing in the towel.

Can't get the two driver side emissions pipes off the back of the exhaust manifold and I think I'm down to one stuck bolt/stud on the drivers side exhaust manifold. :BangHead:

04-06-2014, 06:55 PM
I usually use a propane torch, take your time, get the nut hot, or the manifold if you need to get the stud out. It takes time but it works. Get it red hot, let the red cool out of it and try to turn it. If not, heat it again.
Once it moves just a little work it back and forth tighter and looser. Eventually it will spin right off.

04-06-2014, 06:59 PM
Why don't you cut it off with a sawzall the tubes I'm talking about

04-06-2014, 07:07 PM
I have burned the remnance of a manifold bolt head off and slid the manifold over it to remove . Then you have a short stud left I like to weld a nut on the stud this gets the stud hot and expands let it cool then try to turn if it still is tough heat the head around the base of stud and like traveler said work it back and forth

04-06-2014, 08:08 PM
Good ideas!!! Hadn't tried heat because I wasn't sure I could get the oxy acetylene torch in there without melting other things. Hadn't thought about propane! You guys ever try paraffin wax on a hot bolt. I've heard it works but never tried it. Erik, can you use the propane on the brazing also? Might take longer to warm up the head.

Trying my best not to have to cut the tubes off of the back of the manifolds because they are part of the EGR system and Im keeping as much of the emissions just incase I ever sell it and the buyer lives somewhere where it has to meet emissions.

I'll have to try once the rain stops. Still working in the driveway, might be able to get the build permit for the garage now that my neighbors signed off on my variance.

Just talked to my Dad, who loaned me a car. I've got it for a few more days so I'm going to keep going at it.

Thanks for the help!

04-07-2014, 09:56 AM
Ha, I actually did try to braze with propane just last week. I was working on a gas tank for a boat.
So for normal brazing on light steel. No propane is not hot enough, so then I got a can of map gas. It was able to do it, but the mapp gas barely got hot enough to melt the brazing rod. So no I wouldn't recommend it at all.

Oxy acetylene will work too for heating bolts. Just keep a small flame, don't need to do it in a hurry, that helps you control the what gets hot around you. You are doing delicate work so use a small brazing tip to heat the area you want to work. Not the rose budd or cutting head.

Never tried wax, read about it. Never had to though. For me just getting it red hot, not really red, just red, then letting it cool at little has always worked.
The reason you let it cool is so when you go to turn the nut or bolt it isn't so soft that it just deforms. Turning it while red hot is a bad idea.

You also have to remember the exhaust gets hot, everything in that area gets really hot, so yeah it doesn't seem like a good idea putting a flame down there but all those things are already used to high heat.

04-08-2014, 10:45 PM
Well poop! My inexperience came out. Propane was doing it so I reluctantly broke out the big torch and the lower drivers side emissions tube came out after about 5 heat cycles beautifully. The upper one wasn't cooled down enough so it came undone but only because the 45* fitting on that a screws into the back of the manifold broke off on the manifold side of the angle. The tube is salvageable but just made a little more work. Any idea if that is the EGR tube and what that fitting would be called? It would be easier to buy a new one than try to fix it. Otherwise progress is slow only had about 2 hours to work tonight including setup and clean up. Thank you guys, I'm making progress, slow but its cheap labor.

04-08-2014, 11:08 PM
I think I've still got stock manifold laying around

04-09-2014, 07:55 AM
I think I've still got stock manifold laying around

Let me know if you want to sell the fitting off the driver's side and how much. It should fit in a flat rate box or something small but you'd have to get it out of the manifold. Thank you!

04-09-2014, 07:59 AM
Are you talking about this piece?

<img pxz:uid="-dc42a00b-1" src="http://i6.photobucket.com/albums/y236/2bucks/1996%20Ford%20F350/IMG_8918_zps185e5522.jpg" class="tcattdimglink" alt="" border="0">

04-09-2014, 09:28 AM
Yes! That's it! Wow that one looks worse than mine did, before I broke it. It broke right where the cone shape meets with the round part going into the manifold. I might be able to fix mine or find fittings at Home Depot but I'd rather use a factory piece if possible. Any idea what to call it to look it up?

04-09-2014, 01:55 PM
Well I found a few things searching the interwebs. Sounds like its about $120ish for the part from Ford. I'll see if I can fix it since I bought plenty of brazing rods and if not I'll probably buy the stainless $40 fitting.



04-10-2014, 11:33 PM
Was sick as a dog yesterday and most of today. Didn't get much done yesterday. Today I finally made some progress! Got the passenger side manifold off! And got a look at the carnage. Thread repair as I mentioned on the second to rear bolt hole, need to build out the gasket mating surface less than expected. And the rear bolt hole has a small chunk missing on the top so I'll have to do some thing there...... Or should I think. I'll post pics once I get them off my phone. Drivers side isn't going to go as quick but I got one stud and the dipstick out. Calling it a night. Letting some penetrant soak in and going to use the torch again tomorrow.

04-10-2014, 11:38 PM
Just an FYI for all the 460 owners. I suspect that this problem has to do with bad motor mounts as much as the poor exhaust manifold design. So if you have stock manifolds check your motor mounts very closely. The install instructions from Doug Thorley actually recommends replacing the mounts. They say to lift the motor for the install and so it's just four more bolts. Replacing mine and the transfer case mount.

04-12-2014, 11:14 AM
Last night went welll but slow. Got a few nuts off of studs, got one more bolt out, and two studs loose.

Well this morning started good. Down to the last stud and well it looked like it was moving and I was barely working it back and forth then I though the socket slipped off but it had broken off. It's just below the surface of the head. I think I could get to it to drill it out, front bolt hole on the drivers side rear cylinder. I guess 15 of 16 is pretty good and it could be in a much worse bolt hole. I think it's just barely too low to weld a nut to it. :BangHead:

Just an FYI, I don't recommend doing this in your driveway or on your daily driver without an extra car. Luckily I was able to borrow a vehicle from my parents.

04-12-2014, 09:53 PM
You can drill it, that is probably one of the easier ones to get to. Start with a small drill bit and work your way up in size until you risk hitting threads.
You can try to use an easy out, Heat it, then gently try the easy out.

Worst case, drill it until you are seeing threads, then take a punch and peel it out.
You might have to take the fender well loose. But hey at least it is the last one.

04-13-2014, 12:46 PM
Worse case scenario the thread repair kit came with lots of extras.

04-16-2014, 11:03 AM
Slow but steady. Got all the bolts back in. Welded everything up back to the muffler last night. Then remembered the little two bolt egr connection on the passenger side. Gotta pull the inner fender again. Cranked it up with the muffler and its loud, maybe too loud but sounds real nice. :Pickle: After the rest of the tailpipe goes on it should be a little quieter.

Can't imagine why this thing was leaking.... More pics to come

04-16-2014, 03:52 PM
At least swapping mufflers is easier now if you think it is too loud.

04-16-2014, 10:26 PM
One other detail I forgot to mention. Thorley really engineered their product well. That 45ish degree fitting that broke is not needed with their headers! Woohoo!!!

There is a trick to getting all the emissions connections hooked up. You need three pairs of hands. At least one pair being smaller is better. And connect all of them before tightening any of the header to head bolts/studs. A big thank you to my wife and niece from lending a hand for that part.

04-21-2014, 01:01 PM
Worked on the pipe routing, cutting and welding Friday. Got the passenger side done. It sounds soo mean, very deep tone rumble. It's a little loud but the other side of the y is pointing the sound right at the gas tank so I'm sure it's reverberating off the tank. Welds are pretty bad looking but holding nicely. I did a couple that look good for a few inches.... It also helps when you have the shielding gas valve open. :) Don't have any underside pics yet. Definitely a noticeable improvement to power and mpg. City mpg was looking to be over 10, BUT I just can't seem to stay out of the fun pedal. Maybe on the next tank.....