Have a cracked cast iron passenger side header on my wife's daily driver. I have a replacement but hesitant to remove the old header bolts for fear of snapping one in the head. Don't want this to turn into one of those "shit I did it now moments" Small block Ford and as I say, is a daily driver. Any sage advise from those more savy than I? Thanks for any insight given.
I have never had the SBF , snap the rusted bolts . FEs are the real bastards that suck . You can grind the head off and remove the manifold , then head and remove the bolts .
As deathrowdave said the FE's were notorious and the SBF not so much. As he also said you can grind off the head then remove when you take the manifold off. You can start it and run it to operating temperature then break them all loose. Shut it off and continue to remove them after you remove the spark plugs. It will be hot and you do not want to hold it or let it drop and break your plugs.
^^^^^^^YES! Let it cool on its own, don't quench it. It will swell from the heat, and actually shrink a bit when it cools.
Just the other day watched a Youtube video on removing exhaust manifold bolts from late-model Ford cylinder heads without breaking the bolts, to be successful takes technique, patience, perseverance.
Never, ever had a problem with exhaust manifold bolts on a SBF, and that includes some that were so rusty and eroded that I had to use smaller metric sockets on them. I would recommend using a 6-point socket though. FEs? I always assume I'll be pulling the head to extract broken bolts.
The trick with FE exhaust manifolds is after you've gotten them all out, throw away the remaining OEM bolts. Instead, use a plated (zinc or cadmium) grade 8 bolt. For added insurance, or especially if doing a 'correct' restoration with repo bolts, liberally dip each bolt in Pepto Bismol before installing. The magnesium aluminum silicate in it acts as a anti-seize after all the rest has been burned out.
After it cools to room/shop temp. then go slow, wiggle the wrench loose. tight, etc till it begins to free up.
I have a marine never seize I use on exhaust bolts. Even years later it stays on the threads. I used SAE 286 alloy stainless steel bolts on my SBC exhaust manifolds, got them at Ace Hardware. Not cheap but will hold up to the heat.
Very interesting and I can take it as well should I snap off a bolt flush to the head! I'll do just that. Never ceases to amaze me as to the inovation on this site! Thanks
That was my fear on my daily, the bolts backed right out. No heat, no liquid wrench, no problem! The bolts that will break will be the ones that hold the manifold pipe.
I had a doozy of a time getting them off my 351. Turned out they were all rusted to the manifold itself, and the studs were all finger tight. It took a lot of heating and beating and some leverage to get them buggers out Sent from my moto z4 using The H.A.M.B. mobile app
Well seems like I have a bigger dilemma. Had to make a tool to gain access to the manifold bolt heads as there is no room for a ratchet or breaker bar. Welded a 6 point socket to the box end of a 3/4 inch combination wrench. After days of penetrating oil figured it was time to attack the problem. The first bolt wouldn't budge even with an extension bar attached to the 3/4 inch wrench and almost stripped the head of the bolt. The second bolt head has rusted to a new size too small for the socket. Looks like I'm looking at having to grind the bolts off but of course that's impossible with the engine in the car. Trying to talk myself out of pulling the whole engine at this point. Drastic measure for a seemingly simple task. Have to love working on old cars!
Sometimes a metric socket will work perfectly on an SAE bolt head that is reduced in size because of corrosion. If you have the room, I have had success by using an impact tool, not to break the bolt, but to break the rust loose. I have also found, that the bigger breaker bar just twists off the bolt head, lots of bolt ease and patiently working the bolt back and forth, is the key to getting the bolts out. Like the other posters, the only engine that I have had to break exhaust manifold bolts off, re-drill, and tap, were all on FE heads. This other technique doesn't work well on an installed engine, but I have successfully removed broken bolts, by placing a clean washer over the broken bolt and MIG welding enough material onto the old bolt until you have enough purchase to remove the bolt. Bob
If possible, also try hitting the end of the bolt. Along the axis of the bolt, as if trying to hit the bolt in toward the manifold. This helps break the rust in the threads loose.
If you can get at it use a impact the shock load from the impact is better then just pulling hard. If it is hard to get at use a wrench and a hammer instead. Heat is what I like the best
They used to make 32nd size sockets, all that I've personally seen started at 19/32 up to 29/32, but I haven't seen many new ones listed in years. Proto still lists a 25/32". These can work well on corroded exhaust bolts if you have the right size...
Get'm hot and squirt penetrating oil on them. (acetone and A/T make great stuff but I don't know about acetone and 'heat'! I never had a prob removing mine. You live on some- beach some where?!! 6sally6
Impact gun and hammering on the bolt head is out of the question due to limited access as is using a torch. Maybe I try the metric socket route. Then again ..... Hell, JB weld extreme temp epoxy sounding better all the time! Perhaps it's time to consider an engine upgrade after all. Life was so simple working on the flathead
It might be because I live in Canada, and we have been slowly converting automotive screws to metric, but I have not seen the 1/32nds sizes here in a very long time. A person could probably order them, but they would be expensive, and a person would have to wait for the socket to arrive. The other advantage of using the metric sockets, is that they are dirt cheep, and you can find them in 6 point sockets which are a more positive fit than the 12 point sockets. I have no qualms about welding an inexpensive socket onto a wrench or suitable helper bar to fit in a tight spot. I have a bunch of those kinds of tools that I have built for special jobs over the years. Bob
Why not cut the header off with a sawzall or cut-off wheel, then pull the intake and head? Once the head is on the bench, you can have your way with it. Try your luck with an air hammer on the bolt heads might be all ya need. If not, light off the smoke wrench, heat the bolts to a dull cherry red, let cool to the touch. Hammer wacks on an impact driver might work as well. Good Luck, let us know how you came out!
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