Any tricks for getting exhaust bolts out?

I'm trying to pull the cracked exhaust off my "new" '66 200 motor and it doesn't want to budge. All the bolt heads are rusted enough that a wrench/socket doesn't even fit properly anymore and I tried using these bolt extractors but the correct size spins without grabbing and the next size down doesn't fit over the bolt head.

Any suggestions? Unfortunately I was an idiot and put the engine in the Falcon, so I'm trying to extract it in the engine compartment. And I can't even ignore the leaking manifold until nicer weather because the studs for the exhaust pipe mount are chewed up as well.

I can take pics if it'll help.

Try hitting them with some Kroil, although it will be hard to get them due to the angle. If you can run the engine, turn it on, get it good and hot, then shut it off and try to break the bolts loose (Don't do what I did and break the bolts!) while the block is hot. Just don't burn your hands! Also, take a hammer and whack them good and hard. Just hit them straight on the head - the shock will help break up the rust. Hope that helps!!

It might be faster/easier to get a decent used head and just swap it out.if you really want to save that head, I've heard of people who had good results using metric bolt extractors when the wear was extreme, unless they're round. In the car, I think grinding new bolt faces would be too difficult.

I''ve broken a lot of bolts using a long wrench or a cheater bar. And if the bolt wouldn't come out with the head attached, an easy-out probably won't budge it either.

Years ago, a guy at the exhaust shop demonstrated to me that an impact force is usually way more effective than a hard, steady pulling force. The hammering effect of an impact wrench will usually loosen the bolt without breaking it. He claimed that a broken bolt was pretty infrequent at his shop. I haven't been quite that lucky, but I always try the impact first.

The penetrating oils and heat/cool cycles can help too.

-Stu

Totally agree with the impact suggestion. For seized bolts like that, I usually hammer away at the head for a bit (like, with a hammer), hose the entire area down with Freeze Off a few times over a few days, hammer again, then use an impact on increasingly rough settings until something gives. The trick is the throw enough shocks at the fastener to break up some of the corrosion so the penetrant can get in there and do its job. Freeze Off seems to be a miracle worker, but sometimes you gotta empty a can of it on stubborn fasteners. Between it, Seafoam, and PB Blaster (or all three) the job always gets done.

i'm a firm believer in impact. start with penetrating oils, then rattle it with a small impact gun, 3/8 drive would be a good start, as most of those won't just snap off the bolts you're trying to remove. when you reach the point where you think its now or never, grab the 1/2" gun and give it a quick tap of the trigger.
i've broken off very few bolts by removing them with impact, and only a handful installing them by impact. the key is to know how much force your gun is putting out.

in your case with stripped heads, try hammering a slightly smaller socket on there. metric might be a good choice, or sometimes an external torx socket happens to line up closer. try everything you've got and something should work.
another thing you might want to try is the style of nut extractor used on locking lugnuts, such as the one pictured here http://www.google.com/imgres?imgurl...zHqmViALOuol9&sqi=2&ved=0CNwBEPUBMAw&dur=1389 the one pictured here is sized for lugnuts, but the style exists in various sizes and have the best odds of getting the job done

Having messed up the fastener heads isn't going to help any. But a couple more tips: Always try to tighten them first. A lot of times this will break them loose enough for penetrants to work better. Heating them with a torch helps, but can be dangerous so be carefull. I have a small butane torch that I use for soldering that is more controllable. Once you've snapped a bolt. never use an EZ out. Once that breaks, a machine shop won't even touch it. Good luck.

For those who were wondering, I worked on getting the manifold off this past weekend. Hit all the bolts with freeze-off & penetrating oil a few times in the week leading up to it, and tapped the ones I could reach with a hammer. Couldn't use an impact gun as I don't have a compressor, but used the extractors I mentioned above on a long ratchet handle. End result was 6 came out easily, 4 the heads snapped off, and one the head stripped but once I cut the head off and pull the manifold the remaining bolt unscrewed. The four snapped off bolts were the upper outboard bolts on both sides. I tired everything to twist them out, including welding a nut to them and nothing would work.
So I figured since they had decided to be a permanent part of the head I would use them as such. I cut them closer to the head and welded studs to them(actually additional bolts with the heads cut off), and used nuts to secure the manifold. It went surprisingly easily and seems quite secure. I can post pics if people are interested in my hack-job.

"...faster/easier to get a decent used head..."
not so easy here in the NE states, often everything older than 10 yrs is off to the crusher (BTW: I seek a '77 +, lrg/hex head log).
I use an electric impact, eventho from Harbor Freight it wrks well. Hammered on an impact socket a lill smaller than the oe nut.
Oh well yer beyond that now.
I'd suggest 'center drilling out' what's left of the 'stud' in the motor. A tap to chase the original threads could B used to get U back to where the thing was before. The boys in the ship yrds close to U have this prob with all the salt water & it's effect on metal. A chat w/ 1 of them would come up w/some ideas....
Good luck, keep in touch w/this. :idea:

Good fix with the extended stud. I wonder if it might come out now that it's been subjected to heat from welding. Whatever, sounds like you're pretty resourceful.

I always put anti-sieze on the threads when I put it back together. There are some that claim to resist high heat. I actually don't know if it makes a difference, but hope I don't need to find out.

-Stu

I used stainless hardware to hopefully avoid the rust problem, but I probably should have used anti-seize. By the time I was bolting it together I'd been working on it for 6 hours and just wanted the damn thing done, so I didn't think of it. Maybe I can remove the hardware on at a time and anti-seize them then re-install.

I am a bit nervous about the welding loosening the "studs", but two of them had a nut welded to them to try and get them out and didn't get any looser, so I'm guessing they will be ok. I'm planning on keeping an eye on it for a while.

welding them won't make them "fall out", but may make them willing to come out by conventional means. but since you have it back on the road, thats not important anymore