Hooptie

so I'm trying my best here not to throw a wrench through the windshield of this car. (70 Delta88 455) as the trend continues that once I try to fix one thing something else goes wrong...so I'm so close. after taking 2-3 weeks off of work to specifically work on this car and nothing else, to get it in driving condition. I was down to one last thing. the thermostat. easy straight forward job. well just like the choke heater, both of the bolts broke off. and if these are going to be anything like the choke heater bolts there is a 0% chance they are coming out. so I have to drill and re-tap them. I'm about to go out and buy the nicest metal drill bits I can afford and a proper tap set. my question: if this fails, and I have to replace the whole intake manifold how intense of a job am I looking at? will I have to take off the distributor and re-time it? where do I even find a proper manifold? I've stalked ebay since the choke heater broke off and cant find one for my year that isn't a racing intake. I'm also terrified that the intake manifold bolts will snap off too. every bolt I've removed from this intake has snapped right off. and I'm talking after spraying them with PB blaster for 2 days before even attempting to remove them. if its going to be another job where I have to spend $300 in parts and tools, and have another week in labor ahead... I think my hopes of driving this anytime soon are back down the drain again, and its going to have to sit. this car OWES me some good luck at this point.

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Hooptie

also, does anyone know what the bolt size is for this, so i can get it right when I tap it? thanks guys

garage goat2

In my opinion , I would remove the intake . And no you don't have to take the diistributor out, But pull the carb and work on this on the bench.

RandyS

You may have to remove the intake, but first I would try taking off the thermostat housing and seeing if there is enough of the bolt sticking out to get a vice grip on. If there is, I would heat the area around the bolt with a torch and attempt to back a bolt out. You may get lucky.

RetroRanger

if its a 2bbl intake ill give you one free you pay shipping if a 4bbl i think i have one $50 plus ship either one stock cast iron intake.

CRUZN 66

I believe they should be 5/16 x 18...

Sugar Bear

This is easy to say but...walk away from it for a day if you can. With respect for others advice, I do not see a reason to remove the intake and possibly open another can of worms.

Try to locate a new thermostat housing first as a back up, then drain the coolant down a few inches, remove the thermostat housing (it may break, remember locating the new one?), take out the thermostat, put a rag into the left and the right sides of the water passage where the thermostat sat. Hopefully, the bolts are protruding slightly, if yes put penetrating oil on them and use vice grips to tighten (not loosen) them downward into the manifold to break them loose. If possible have someone tap on the top of the bolt with a punch and hammer while tightening them. Once the bolts break loose, remove them upward so the threads in the manifold don't get damaged from the vice grips being on the broken section.

If you can apply heat to the bolts, spray them warm and walk away it helps a lot because it wicks the penetrant in as it cools.

Worst case drill and tap, not a big deal.

Yes 5/16 - 18, I don't know the length.

Good luck!!!

Hooptie

awesome! thanks!

the water neck is threaded through the holes, and snapped off at the very top. so I don't think I'll be able to get it off without drilling.



oh. awesome! thanks! if you have a good 4bbl manifold with the port for the choke heater then I'd be interested in buying it. just in case the drilling doesn't work out. thanks

Sugar Bear

The water neck definitely should not be threaded. The threads are in the intake.

m371961

Removing stuck bolts is a chore. All the above apply. They do not thread through the neck, only into the manifold, otherwise they would not tighten the neck down. I would continue to deal with it and not pull the intake. Tap around the base of the neck and keep soaking it. It will pop off. If you have to drill after the neck is off I would install heli-coils and use stainless studs and nuts to reinstall. Make sure neck is flat and smooth on bottom. Welcome to the art and frustrations of dealing with old cars.

Hooptie

yeah, it wasn't threaded it just looked like it cause the rust was so bad. I tried tapping it off with a mallet for about 30 min before I just decided to drill with it on there which got it off. now I just need to get the right size tap and hope it works. to add to the fun I'm not so sure the thermostat was the problem anyway. I tested it and it did open.

76olds

Buy a good 3 flute tap rather than a 4 flute for cast. John is correct they are 5/16-18.
You could go to 3/8-16 and clear the T-stat holes out to accommodate.
Nice of RetroRanger to offer up a 2 barrel intake free if your is a 2bbl.
A 4bbl for $50isn't bad either, you have options.
All the best with your repairs
Eric

MDchanic

This happens all the time.

As others have noted, heat will get these out, but it sounds like you're past that now.

Centerpunch and drill as close to center as possible. If you drill a little undersize, and you then apply a good amount of heat, you've still got a good chance of peeling the skin of the old screw out of the original threads.

Once the screw stubs are out, and the threads are cleaned up or re-cut, I would recommend using stainless steel screws and Nevr-Seize, so that this doesn't happen again.

- Eric

Olds64

x2

I use anti-seize on most of the threaded fasteners on my engine. I figure, it might not have been used "back in the day," but after working on modern aluminum engines with steel fasteners it's become habit I guess.

Good luck making the repair. Keep us posted.

Professur

OK, first off, lose the vice grips guys. A small pipe wrench has many times the bite. Failing that, the best way to get a broken bolt out is to weld a nut to it. No drilling necessary. Anyone with a welder ... be it stick, cheap *** flux core, or a tig can do it. There's more than enough heat to break the rust too.

On an aluminum engine or head, you can burn a steel bolt out using an alum solution. Plenty of Youtube videos on it. The alum eats the steel, but won't touch the aluminum threads. It can take a little time, but the benefit far far outweights the cost.

Olds64

Never heard that trick before. It's good to know though, thanks for sharing it. I've gotten lucky removing bolts in the past. I just use PB Blaster liberally for a day or two and they usually come right out.

Hooptie

Update: I think I did this the right way this time. the last two bolts that snapped off ( choke heater) I went straight to an easy out. and I will never make that mistake again. once the first two easy outs snapped off in both bolts, they proceeded to eat, no lie, 2 more easy outs, 4 titanium dremel bits, about 10 titanium nitride drill bits (they were harbor freight), and 1 punch head. over 3 days of trying to get some sort of hole back. I settled for like 2 threads on each side and was just happy the thing was on there only slightly tight and with a lot of orange permatex. this time I went and got expensive drill bits and the right tap. and just started by drilling them out. with a lot of patience it worked out Ok. my holes were a little off, but I got two new stainless bolts with anti-seize on there and managed to tighten it to spec (20 ft lbs) so-far no leaks. and the car seems to like the new thermostat. I won't know for sure till I can drive it for more then 10 Min. but it stayed at a steady 190. and I can finally see the coolant move. thanks for the help guys!

droldsmorland

Like MD said Anti seize and or stainless. Be sure its not china SS bolts. Also cut the bolt so there isnt any or very little threads protruding into the underside. This is one of the causes of this common problem, the threads get rotted off and wont back out. Another reason to flush your cooling system regularly as well as adding a rust boost inhibitor/pump shaft lube.