fussy manifold studs IDEA??

[78Suburban]

I had to take off my old exhaust manifold, now I need to put it back on. the 2 of the 3 studs on the bottom, have nuts threaded on them now (although not very tight, as I'm scared of stripping the old brass nuts). But the 3rd stud seems to be stripped, or maybe its the brass nut, which looks to have less threads than the stud.
I have tired to remove a stud from an old manifold I had laying around, and there is no way that rusty thing is coming off. I seriously doubt that I will be able to remove the stud from the manifold I'm trying to use..

So here's my idea....

grind all the studs off, and drill holes where the studs were. Don't worry about tapping threads, but instead just drop some grade 8, 3/8" bolts in the holes. thread a nut on the bottom side, and tighten untill the flange with 3 holes is snug. Call it good..

Does this sound like a bad idea, or a good way to make a crack in my manifold? One other possible solution, might be to just get a new fine threaded nut and TRY to see if it will thread on the old stud, but I kinda doubt it.. the threads are just so danged rusty.. I kinda doubt if the 2 nuts I have already threaded on are really holding all that strong..
Any suggesions are welcome,
James

 

[BadDog]

Somebody did that to one hole of one of my manifolds where it seems to have stripped. And I would like to throw it at them, whoever they may be. It's an SoB to get to some of them in the truck to hold them, especially once they start rusting. I very nearly had to pull the manifold or cut the exhaust tube just to get the motor out. Once I did get it out, I fixed it right by installing a Reli-coil along with a factory stud along with anti-seize on all the nuts. Another thing to think about is that many models (later) have springs that require a specific pre-load to function correctly. I've seen more than one set of springs killed (along with leaks) due to over-tightening on incorrect studs...

 

[3 on the tree]

Heat the studs with a propane torch, blast em with break free, heat again, get some GOOD steel nuts, double them on the stud, and see if you can turn the stud out and put new ones in.

 

[DieselDan]

get some GOOD steel nuts

Not trying to be a dick, but why would you want steel if brass nuts were available? I've used copper exhaust nuts on other car manifolds with good success. Yes they're soft but they don't sieze on the stud. Do you (or anyone) have a different experience?

 

[cybrfire]

Heat the manifold around the stud is the only way I've ever gotten the studs out. Good luck.

 

[diesel4me]

yup ----fire is good!-exhaust studs SUCK...

Heat the manifold around the stud is the only way I've ever gotten the studs out. Good luck.

Use an oxyacetalyne torch..propane is a waste of time and money 90% of the time on exhaust studs..I have to get my manifolds cherry red or hotter before the studs even think about coming out!..have to heat them several times often,turn them out some,then heat again,to get them out without snapping them,and having to drill and re-tap..

I've used 5/16 bolts and nuts rather than studs on a few of my heaps where looks were not a priority..it works,Mpoars used that setup for years..I kind of like the idea..since I've NEVER successfully unscrewed a exhaust manifold stud once within 3 years of installing it,due to salt induced corrossion,I think its a lot easier to just take the torch to bolts and cut them off,and slip new ones in..saves a lot of dorking around when doing a Y-pipe on a Mopar V8,vs a GM.....

But it seems to work better on Mopars...many Chevy exhaust manifolds have one "blind" hole,that cant be drilled all the way through..and even with 5/16" bolts,you have to grind one side of the bolt head off to get it to go thru the hole straight!.(unless you use allen head bolts!)...so they aren't a hot setup either,but work as a "quick fix",temporarily at least..in 2 out of 3 holes in some cases...

I've tried brass nuts on steel studs..the exposed threads on the stud beyond the nut rot away,and the nut strips as you try to loosen it..even if you heat them up---...failure..

I've tried using Brass studs AND nuts too!..they are too soft,and twist off like a tootsie roll next time you try removing them..easy to drill out though..never had one break "in use",but I'll admit I was kind of waiting for one too,but they suprised me..

I've tried stainless steel studs AND nuts too..expensive,and they never rust..but they also get hard as glass after many heating and cooling cycles,and snap off like peanut brittle when removal is attempted..and GOOD LUCK finding a drill that will drill thru them!..I used all my 5/16 drills,and had to pull off the manifold and have a machine shop MILL the holes out with an end mill..no way I could have done it at home..

I've just learned to accept no matter WHAT I put in the manifolds for studs and nuts,whether its grade 8,cheese soft threaded rods,stainless,etc..none of them will outlive the pipes they hold on,and will break almost without fail.."Never Seize" doesn't seem to last more than a week on them too.. ..

I kinda wish they used pipe threads INSIDE the manifold,like a briggs and stratton,only with 2-1/2" pipe!.. ..then I could use schedule 40 pipe ,not tubing for exhaust pipes..THEN I might finally get more than a year or two out of them!..

 

[3 on the tree]

Not trying to be a dick, but why would you want steel if brass nuts were available? I've used copper exhaust nuts on other car manifolds with good success. Yes they're soft but they don't sieze on the stud. Do you (or anyone) have a different experience?

The steel nuts are just to turn the old studs out. Guess I should have explained that-DOAH!!!!

 

[78Suburban]

The old studs still do have some threads left. Nuts will thread on 2 of the 3 studs. The real problem stud seems to have brass in most of the threads, which came from the stock, stripped nut. I picked up 3 new fine thread steel nuts at the hardware store today. I have tired to chase the threads on the studs with a die, but the die handle is so long that it hits the other studs. maybe I can use the die with some pliers to clean out the threads on the problem stud, then install the manifold with steel nuts.

If worst comes to worst, I guess I could get my girlfriend's dad to heat the manifold with his cutting torch. I kinda doubt if that will even remove these rusty old studs. I was told that I could bring them to a machine shop and have heli-cores put in them, and then new studs.. but at some point I am going to have a whole bunch of $$ into a 30 year old exhaust manifold, which seems kinda silly to me. So I'll try to clean the threads and use my steel nuts. If that fails, I guess I'll give the oxyacetline torch a try.
Thanks for all the advise so far... keep it comin ,
James

 

[Chaddy]

mabey weld a nut on the end and use a torch to get it out?

 

[diesel4me]

migt take time..

I've had to salvage a good many exhaust manifolds on rare antique cars and equipment,and its imperative that I didn't FUBAR the only original one we had available in many cases...gets the adrenaline flowing,and the stress level WAY up!..and despite my best efforts,a few didn't survive--my name is Bob,not Jesus or Houdini,I'd tell my boss!..

I usually heat AROUND the stud where it goes in the manifold..you need to get the manifold orange hot,almost to the melting point,yet try to keep the stud itself as cool as possible,otherwise it will twist off like taffy!..double nuts or one welded on works well to remove them..

I use hand tools,and be careful not to bend the stud ,it will make it snap MUCH easier if its bent,or if you tug on the wrench cock-eyed!..an Impact gun usually twists them off instantly..don't be tempted!..it takes some experience to know when to stop tourqing on the wrench before its TOO much,and the stud breaks..

If you think you could salvage the threads with a die,there are hex shaped "thread restorers" available..I've used "Castle Nuts" put on with the serrated "castle" portion UP,as "thread chasers"..work pretty good,and don't cost much at Lowes or Home Depot...use lots of oil or kerosene on the dies or castle nuts..

I made a holder for my round dies out of a peice of water pipe with the right inner diameter,with a few setscrews drilled and tapped into it to hold the die.(or nuts could be welded over the holes in the pipe).

Then I welded an old 3/8 socket to it so I could use a ratchet on it--you might even be able to drive the die into a 12pt deep socket and use it that way too possibly..but if the studs are that badly rusted it might be best to change them..

Worst case scenario is they break off,and drilling them is unsuccessful..there are many places,including junkyards,that sell NEW manifolds now for between 50 and 100 bucks..they are selling like hotcakes here in New England..costs that much to have the old manifolds "fixed" in many cases... ..

Your right to think its silly to waste money on a 30 year old manifold..but 10 years ago,all theese "aftermarket" ones were not available,and you HAD to fix what you had,or scour swap meets and flea markets for a replacement if yours was junk..wish I had that option then..

I paid 100 bucks a pair for "Ram's Horns" old style small block exhaust manifolds that were just in useable shape!--now you can buy a pair of NEW ones for that price!.. ..

 

[78Suburban]

diesel4me, I just wanna say that you make some of the longest, best, and most helpful posts on ck5. I think I've settled on trying to tacke this problems starting with the cheapset solutions, and going from there. All of this is temporary anyway, cause one day I'm gonna win the lottery and get some thorleys and a custom dual exhaust
thanks,
James

 

[diesel4me]

Thanks!..

Its nice to be appreciated!..sometimes I wonder if anyone reads my posts--I know many of them are long..but I try to get the message across ,and sometimes it takes a lot of words..glad to know I haven't bored everyone into skipping over my posts,and I'm not just typing them for nothing,..and I hope I've helped a few of you out here on CK5..

 

[dyeager535]

Heat the manifold around the stud is the only way I've ever gotten the studs out. Good luck.

Agreed!

The only way (as in best, not literally) to pull studs that are rusted in place is to take an oxy-acetylene torch, heat the manifold, don't hit the stud at all with heat, to cherry red completely around the stud (no you can't keep the manifold that hot all the way around the stud at the same time) and turn it out with vise grips.

Seriously. I've pulled more studs than I care to, (which would have been one lol) and it is worth your time to find someone with a torch, even pay them if it cost a couple $. If your time and frustration is worth anything at all to you, once you've done this method, you will never think of trying any other method.

You may think it won't work, but if it doesn't work for you, it's because you didn't get the manifold hot enough. Propane MIGHT work, heat still expands metal, but a torch is guaranteed to be hot enough for the most stubborn stud.

I can't imagine anyone (myself included) that has tried various methods would recommend any other method than the torch. If you've got exposed stud to grip with visegrips, do NOT attempt to twist it out without getting a torch first...if you break it off flush, you then end up drilling/tapping, and you've just made more work for yourself.

 

[resurrected_jimmy]

I've had to salvage a good many exhaust manifolds on rare antique cars and equipment,and its imperative that I didn't FUBAR the only original one we had available in many cases...

I want to hear more about breaking irreplacable exhaust manifolds. What were you working on Duesenberg's or Stutz Bearcat's.

 

[shane74]

I second diesel4me on the torch. Cast metal does not melt with a torch like other metals do.

I have burned many broken and/or stripped studs out of stock cast exhaust manifolds. You have to know what your doing, and pay attention, but the bolt/stud will melt and burn right out of the exhaust manifold. Then run a chaser tap through it to clean up the threads and spin a new stud into it. Done.

 

[diesel4me]

Nope..no Dusenbergs or Stutz-Bearcats!.

I didn't work on Leno's cars!..but at the boneyard I was at,the owner was about as rich as Leno,and had many rare cars..many of which were resurected right out of the yard!..

One was a 1954 Packard Carribean convertible with a straight 8 motor..had many other rare ones too,like a 1928 REO "Speedwagon",all original,down to the 7 lug WOOD SPOKE artlillery wheels..many old caddy's,including one just like Elvis's 55 convertible..many Lincoln Continentals,including an old V12 one,which was converted to a BBC by a previous "butcher",and he wanted it restored back to original with parts from a similar one in the junkyard..A few 50's Kaisers,and other assorted weird cars like Sunbeams and Hillmans from the 50's..among many other interesting vehicles..like 2 London Taxicabs with "Sims" diesels!..

Sadly,many waiting for sale or restoration were disposed of when the yard went out of bussiness..the owner died in 1997,and there were still a good many cars he wanted to restore..many were too far gone for most to consider restoring,but he had the money,and enough similar cars to pull parts from to do it!..there was a 1964 Chevelle SS convertible there..rotted to death!..still had the original 283..the VIN# was 000001 !..the motor had a "C" on the casting in the rear too..supposedly convertibles had the motor marked that way..the motor was sold ,and the rest went in the crusher..it was a sin,someone should have never junked that car and let it sit 15+ years in the woods!..I bet it was THE first SS convertible off the assembly line in 64!..

So you can see why we didn't want to waste any manifolds if possible..not many for those cars around..plus we'd try selling many of them,and people want them ready to install,so if the studs broke or already were,we'd have to remove them!--in fact,the yard itself WAS about the only place to get any manifolds or other parts for those kinds of cars....we had people from all over New England,and many other states ,even Sweeden and Germany and the Netherlands visit the yard for parts during summer vacations!...

I agree with Dyeagear,if you've removed one stud,it feels like enough to last a lifetime..the guy I worked with at the boneyard was a master with the torch,and at getting broken ones out--if even a tiny nub remained sticking out,he'd get it out with vise grips nearly every time..another guy used to work for Midas Mufflers for many years..he could blow snapped studs right out without removing the manifolds,and just run a tap thru the hole!...they taught me all I know about using the torch..but I'm nowhere near as talented as they are with one..I get by though..

Worst ones are the ones in "Blind" holes,that have to be drilled..I found welding a nut placed over the broken remains worked good sometimes..let the heat soak into the manifold for 3-4 minutes before trying to twist the nut..if that failed,I tried to always use a drill press with a tilt table to drill them..too easy to go crooked with a hand drill.. ..

I'm glad they are selling cheap "NEW" manifolds now fo a lot of GM's,and Fords,some other makes too....saves a lot of time,money,and frustration..here the cast iron ones dissapear on many 70's 80's and even 90's vehicles amazingly fast from salt.getting hard to find decent used ones now...