460 Exhaust!!!
 

Hey guys,

I have an exhaust leak at the manifolds.
What is the best solution to use?

A. Take off the manifolds clear away any gasket left over and tighten the manifold back down.

B. Or would it be a good idea to invest in a pair of headers.

This 460 has been installed into a 78 Bronco. There may be some room restrictions with the frame, starter, trany. etc...

Thanks

Depends on where the leak is. Is it the manifold to head area? Is is a broken manifold bolt? Is it the manifold to exhaust pipe? I have read some of the stock manifolds develop cracks.


What year?

A leak could be several areas with very different fixes. Also the 460 manifolds I think used to have usual manifold to exhaust flanges with a gasket. Later models have a cone and cup design which in my opinion is prone to leaking due to heat(like towing) softening the pipe and allowing the cone to shift.

If it is a manifold to head leak, then removing the manifold and cleaning the area and using a new gasket is a good idea. Be SURE to use some sort of penetrant on the bolts. If the manifold has been in place for awhile the bolts may be rusted all to heck and you have a good chance of breaking some, and then you have a real PITA.

I would bet someone makes headers for just your swap. If it was me, I would probably go with a good set of headers. But then you are probably not suffering from any lack of power as it is so if your stock manifold is in good condition, it may be just easier to keep it.

It is leaking from manifold to head, and yes the bolts are rusted badly. I am interested in using long tube headers if possible. I have plenty of HP had it dynod pushing a little over 500 HP. Headers would make a little difference though.

Yeah, was afraid of the rusty bolts. Best bet is to spray the bolts with a penetrant while the engine is warm. Follow the instructions, which usually say tap on the bolt a bit to set up vibrations which help the oil to penetrate. I would do this several times the night before I wanted to get to work and again before I started working on it.

Liquid Wrench works OK, Silikroil or Kroil from Kano labs works, something sounding like PB Blaster seems to be a favorite of some of the guys.

A broken bolt is a real PITA especially if you don't have any room to work in.

Remove the bolts carefully. Maybe a little heat from a propane torch may help.

If lord forbid you do break a bolt, let's hope it leaves eomthing to grab on to. Then various tricks can be tried. Some recommend heating the bolt til it is very hot and then touching a candle to the threads so they wick up into the rusted area. Some recommend welding a nut to the bolt and then removing.

If you have to use an easy out DO NOT break it, or then you really have a problem. Some recommend a reverse twist drill instead. They drill the hole and a lot of times will cause the bolt to turn out due to heat vibration, torque and luck.

If you do break the bolt, check this website for discussions on how to remove.

Good Luck,

Jim Henderson

500hp with manafolds?

If ou do swap to headers, invest in a good set of aluminum gaskets or something similar. Unless you enjoy replace gaskets. I replaced 2 sets of regular gaskets and then went back with the aluminum ones and havent had an issue since. over 3 years on them now.

Mine blew out a gasket, so I just pulled the manifold from the block about a 1/2", removed the old gasket and torqued it back down. The leak is completely gone.

Did you oput a new gasket in, or you just went bare head to manifold?

I removed the gasket completely and torqued the manifold back down. It does not leak at all now.

If you break a bolt, and have to drill, leave the manifold in place or fab a jig out of 1" steel to act as a guide. The drill WILL wander off. Don't ask how I know

To fab a jig, do you happen to know the bolt spacing and exhaust port spacing? I'm not sure I trust reading measurements off a ruler...

Thanks

I broke 2 bolts today after using PB blaster and WD40 by both spraying when hot and spraying a week ahead of time for 2 or 3 applications.

3 of the bolts had already broken off on their own so now I'm looking for options since drilling with a right angle drill is tough since we cant get a lot of leverage on the front bolts behind ths shock tower.

ANyone have any ideas on how to get them out? Can we torch them out?

Here's a pic to keep everyone from trying this at home :-arrgh


https://cimg7.ibsrv.net/gimg/www.for...f1067dfa21.jpg

Oh man. My 460 has an exhaust leak with headers. This scares the **** out of me. I was going to get new headers and put them on but now I'm afraid to even put a wrench on the rusty old ones..:-X15

Oh wow :( . I have a exhaust leak too from the head to header connection, I'm a little worried now. Ill respray and tap them all night now. Post the removal processes of the broken bolts..

A buddy of mine had two broken off bolts and he took it in to a muffler shop and they just torched the old bolts out. Took them twenty minutes and charged 100 bucks but he didn't mind at all!

When I rebuilt my first 460, it had the #7 port rear bolt already broken, but the rest came out fine. I warmed up the motor and let it cool back down, and removed them when the manifold was only slightly warm to the touch. Right or wrong, this process worked, and the motor had about 210k on it at the time.

The jig I made to drill out the broken bolt was off by a few thousandths, at a slight angle, but I drilled it out to 25/64ths, threw in a helicoil, and she worked just fine.

I have one that's stripped out on mine I need to work on. I've never used a helicoil before. How hard is it to put one in?

I can't imagine it being very fun with a 90 degree drill with the heads still on, but if you have them out and get it drilled straight, it is cake.

I was just mustering up the courage to pull the manifolds on mine.... and then I come on here, and see something like that ^. The rear passenger bolt has already sheared off, but there appears to be plenty to grab... I have nightmares about many more breaking flush off with the head, and then I'm pulling the head, which I DONT wanna do...

When I forst got the truck I noticed the leak and found a few of the rear bolts to be loose... Maybe there is hope...

I've always had luck as someone else had mentioned with getting the engine hot, and then allowing to cool enough so that you can work...

She's my daily driver so I don't wanna get myself stuck...
Maybe ill continue to live with the leak :-X16

Still planning on gathering parts to do this... But looking around I see no "quality" exhaust manifold kits. It appears Dorman is one of the few who make them? I've never had success with their junk... Dealership I guess?

You might consider a pair from the JY and then take them to a machine shop and have the mounting surfaces trued up. Just a thought.

I had to do a couple on my 89. I took the front wheel off and pried the inner fender liner up out of the way and it wasn't that bad at all. You could get to them easy then.

Sorry I missed a word in my post... It should have said manifold stud kit...

I'm surprised ARP doesn't make them...

But yeah, Ill likely take my old manifolds in to get machined so long as they're not cracked...

460 factory exhaust manifolds are known for expanding and breaking the head area adjacent to the outer mounting stud. After you get a cast iron expert to weld up your head, you prevent it from happening again by drilling the mounting holes in the manifolds somewhat oversize. Leave one near the center of the manifold alone, to help locate the manifold. Drill the holes near it 1/64" over, and the outer holes 1/32" over. If you haven't had this happen yet, and you take the manifolds off for any reason, you should think about drilling them out this way in advance.

MIG welders must have been invented for removing broken studs, they work so well. You don't have to be a good welder to do this. Build up a glob of weld atop the broken stud and wind it out while it's hot with a Vise-Grip. If you break off the glob of weld, make another. Alternatively, some prefer to weld a nut (on the inside) to the broken stud, and wind it out with a ratchet and socket.

I usually weld the mountain of bead and then use this to center a nut.
Weld around the nipple I made to the inside threads of the nut.
Getting the bolt glowing hot tends to break the rust down.

Removing the wheel and plastic inner fender makes access a LOT easier!

In 2008 when I swapped engines I installed regular stainless steel bolts.
It's great!
They don't seize and they heads are still full hex. :)

Your already going to have to remove headers to fix exhaust leak.... Put some new shorty comp headers on that bad boy and make her roar!

when he torched them out, did the exhaust shop have to re thread the holes?

when he torched them out, did the exhaust shop have to re thread the holes?

I had this very same thing happen when I did the headers on my 97 f250. I broke #7 bolts. I made attempt at welding and torching them out but failed. By the time I tried removing the bolts I could had the head pulled off by then. To reassure that don't have any leaks again and again, I used Remflex gaskets.
Remflex Exhaust Header / Manifold Gaskets I've never had to re torque them since install. well worth the $75 for the set.

http://www.ebay.com/itm/SCE-Gaskets-4135-Exhaust-Gaskets-Header-Copper-Ford-Big-Block-385-Series-Pair-/191354360330?pt=Motors_Car_Truck_Parts_Accessories&hash=item2c8d9bd20ahttp://i.ebayimg.com/00/s/MjY3WDQwMA...UKzjv/$_57.JPG
These are the gaskets I like to use. They work very well for headers OR manifolds.