340 exhaust removal

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rigger3006

rigger3006

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72 340 duster,original exhaust manifolds, haven't been removed since 1985 . so of course the front drivers stud stripped and the rear snapped off. I walked away for my sanity and hopefully some help. should I just pull engine and try to get them off with engine on ground? I do plan on changing heads, not sure which ones yet!
 
:banghead:I can see why you would walk away....I'd be pissed!!! Unless you can get a drill and drill bit in there it's going to be tough. It's hard enough to drill out a broken stud when the head is sitting on the bench. You have to drill it right in the middle and hope you can break it loose with an easy out. The stripped one might come out easy if you heat the head with a propane torch but you'd still have to pull the head to get the rear on out if you can't get a 90 drill in there!!

treblig
 
yes i want to pull the heads but i think i need manifold off to get bolts out. pics, no.just got a brand new computer and still trying to figure it out. not that i never knew how anyway.
 
I had similar issues with dads 273. i pulled drivers side head with manifold attached. Frickin heavy!! An extra pair of hands would help. i loosened up mani to gain access to head mounting bolts to loosen them.
 
im sure that would be a good pull! will get back at er tomorrow, gotta try and figure out how that second bolt back from the front drivers side comes out
 
Spray where you can with WD-40 or similar and let it sit overnight if you can or use a torch. (propane or not too much heat with the other one.
 
it does sound like taking the head(s) out of the car is the way to go - disconnect the exhaust pipes from the manifolds and lift the entire head and manifold out as one piece - yep, it'll be heavy. Once it's out and on your bench, heat - PB blaster - a drill and easy outs - vise grips - whatever it takes - - oh, and BE PATIENT!! You don't want to make it worse than it already is. I had this happen to a Jeep I had, because I had never dealt with such a thing, I called a buddy... get a friend to come over and help. :glasses7:
 
The hole in the manifold is about 3/8. With it bolted in place it serves as a pilot for a 3/8 drill bit, then a 3/8 shank center drill ( #4 if my memory serves ).
Grind away any stud remaining to flush with the head. center drill, then drill and tap to 5/16.
Nothing hard was ever easy but it is doable. Brake boosters, master cylinders, etc.. will be moved out of the way. Motor mounts unbolted, and engine rotated sideways to get a better angle on the dangle, whatever we need to do is what we do.
 
the way it usually goes for me is
1) break bolt or stud off in head "insert bad word here"
2) Drill a hole in stub/bolt
3) Insert and break off easy out in head " insert more bad words here"
4) Try to drill out the easy out, but it is harder than the drill bit, "insert a few more choice words here"
5) Drill a much larger hole and either helicoil it or use a larger grade 8 bolt.
6) Remember to never try easy outs again.
7) forget about 6 next time and start at step 1)
 
I do plan on changing heads, not sure which ones yet! < this is why I think you are better off just getting them out of the car..
 
Take the top end off, you are going to be doing it sooner or later.
If you're changing heads anyway, why bother to try to remove the broken off bolts/studs in the car?
You can do that much easier when the heads are out and on the bench.
Use a torch to loosen the bolts in the first place by heating where the threads go into the head, get it good and hot there.
If the engine still runs, warm it up to operating temp. and loosen the bolts while the engine is still hot.
 
Treblig said:
:banghead:I can see why you would walk away....I'd be pissed!!! Unless you can get a drill and drill bit in there it's going to be tough. It's hard enough to drill out a broken stud when the head is sitting on the bench. You have to drill it right in the middle and hope you can break it loose with an easy out. The stripped one might come out easy if you heat the head with a propane torch but you'd still have to pull the head to get the rear on out if you can't get a 90 drill in there!!

treblig
Click to expand...
been there, not a good idea, pull the head let a proper shop handle it if $$ allows it.
 
success! i pounded on a 12mm socket on stripped front bolt and snapped it off the way they usually do! same thing happened on one of the middle ones on the passenger side. cut exhaust pipes off underneath car and pulled them out, drivers side was crimped down to 3/4" in one spot all the way to 1 3/4", cant wait to put on headers and some pipe. thanks for all the advice, i know its gonn a come in handy when i try to remove water pump and timing chain cover. now to trade manifolds for an rpm air gap hopefully!
 
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