69 Cobra Exhaust Manifold

[machyoung]

So I have to change out a drivers side exhaust manifold on 69 Torino Cobra w/ 428 CJ. Daunting task at best. I understand the basics, penetrating oil, then more penetrating oil, if possible run engine till warmed up (hot) and then good luck! Ugh! I've read numerous posts; remove the head and manifold together and then remove manifold once on bench, remove engine, etc., etc., etc.

Anybody got any good ideas? I am up to the task of busted knuckles, burnt knuckles, modifying wrenches, etc. After all, I have 2 of these cars w/ headers. This is the first one that I am trying to keep original (it's a bone stock 56,xxx original). Good chance I'll break a bolt(s) so off comes the head anyway. Again, ugh! Ideas anyone?

[cammerfe]

In my experience, once you break a bolt in a blind hole, the answer is to VERY carefully center a back-twist drill on the broken bolt and drill it out, then with a series of tools such as dental picks, dig the bits of threads out  of what's left in the hole . The hole must be, as closely as possible, sized so as to remove the body of the bolt while not taking the threads out of the casting. Copious amounts of cutting oil and a tiny ball stone in an air tool will make it most possible to dress the broken end in order to get the centering right. 'The various sorts of 'easy-outs' are very likely to expand the shell of the bolt and make it hold tighter to the parent work-piece. Do the drilling in a drill-press.

Good luck---you'll need it. I once had to take an English cast-iron brake-caliper over to a friend in the tool-room at T&C Livonia after I boogered it royally. They fixed it by boring out the casting and furnace-brazing in a piece of cold-rolled rod. Then they re-machined the entire casting from scratch. If I'd have had to pay for that 'government-job', I could probably have bought a half-dozen brand new calipers for half the price. But they were 'out-of-print' and would have likely taken a three-month search in England, and I needed to drive the car, an Austin-Healey 3000, the next morning. It's good to have friends.

KS

[Rory428]

I have never broken a horizontal exh. bolt on a FE head, usually just the uppers that go all the way thru cause any grief.A passenger side exhaust manifold on a 428 CJ are all horizontal, that said, if the engine is all original, it`s possible that the bolt heads may have "shrunk", due to 50 years of errosion. I don`t envy you, its not a fun job.

[manofmerc]

I believe you would be better off to pull your engine .If those ex bolts have been removed and replaced with neversieze on  them you might get lucky .But if those bolts haven't been loosened in years you are going to have a difficult job. I owned a 69 cyclone for over 30 years lucky for me I didn't have to remove those exhaust manifolds .Even if you pull out that engine it still isn't easy like Rory said the bolt heads seem to shrink .Get yourself a new six point socket .Good luck! Doug

[machoneman]

Strange, but I had never seen what someone did to an FE until a car show 2 weeks ago. My eye first caught shiny bolts on the top flange of a '63 boxtop Galaxie's 390, but on closer inspection the owner, or his builder, drilled out the threads entirely.  A SS bolt, lock washer and nut were used to secure the topside flanges to the head. Actually it was well done, not a cheap rebuilder  shop trick, and looked just fine if unusual.

[turbohunter]

I’ve seen that nut on the back deal done as well.
But to the op’s question....it’s a bitch. Just take your time. Once you break one there are a couple ways to do it. Welding a nut on and drilling out with a reverse bit. If you use a drill try and grind yourself a flat surface to use a center punch on or you won’t get it centered.
Good luck.

[machyoung]

I am trying to avoid pulling the engine but understand that in the end it might be what's needed.

There is a shop here in Orange County (Santa Ana) that removes broken bolts, studs, etc., Jerry's Tap Removal. They use a metal disintegration method that really works. They have been in business since the 60's. I have used them several times over the years.

If I have to pull the engine, I am afraid of the snowball affect. 

[TomP]

You would only likely break the one at the top of #8 but that would be near impossible to drill in the car. You may end up pulling the head off to fix it.  So try that bolt first and try to heat the top ear of the head and use wax and whatever other trick. If it breaks then pull the head with the manifold attached. If you are able to remove the rest will be easy.

[machyoung]

Thanks all for your assistance...

Well, here's the update. Removed engine. Patiently and methodically removed the pass side w/o issue (BTW, 14mm box end is slightly smaller than a 9/16 and was certainly necessary to keep wrench from slipping/stripping). Manifold came off in 2 pieces. Upon inspection of drivers side noticed crack in ear at #8. Upon attempt at removal, ear broke off and bolt broke leaving an ever so precious 1/4" protruding. Also broke a second bolt in the process 1/4" proud again. I'll work on those and see. Score - pass side 0, drivers side 2.