I've got an old Edelbrock C3B intake. Someone capped off one of the heater hose ports with a steel pipe plug in, I'm guessing, 1969. The two metals have become one. I'd like to use that port. Any suggestions on getting that pipe plug out of there? I'm obviously worried about stripping the threads out of the aluminum, but it's in there so tight I'm even worried about breaking the manifold by putting too much pressure on it. I've heated the plug with a torch, and I've coated the visible portion of the threads with wax in hopes that old trick works...nothing. It's on the engine, and I'd rather not remove the intake to drill it. Any other ideas I might have missed? -Brad
With it off the engine ... I have drilled them out ... starting small and progressing larger until I got almost the correct size for tapping. Then I could take a chisel or a punch and " tap " away portions of the remaining plug. Then I re-tapped the threads On the engine ... ??? not a clue ...
If'n it was off the car I would say soak it (the area around it ) with Coke. Go back in a day or two and tap it with a hammer...then repeat. Sometimes that with diffuse dissemillar metals bonded together. (Where the **** did I come up with that ! ) On the engine is another matter.
Try using a 6-point socket and Torque wrench so you can see how hard you're pulling; tap with hammer while turning. If it tears threads when it comes out you can prolly re-tap it 1/2" NPT since the threads are tapered but you may have to pull the manifold to re-tap.
Try taking the fitting you want to use, cutting the top off, and welding it onto the plug once you've drilled a through hole. Depending on skills and equipment it may be the fast and easy way.
Hoe about drain a little coolant, pull the thermostat and fill that side with shaving cream and use a magnet when you are done?
Hey, Given the years the plug has been in the manifold, and the possible electrolitic issues ,I'd drill it out as suggested. If you do damage the manifold upon removal of the plug, you'll be removing it anyways! Start with larger drill bits after you center punch the plug, and when you get close to the o.d. of the steel plug take a small curved hook tool and roll out any remaining steel. This will take some time, but so will instalation of a HeliCoil or welding the manifold if you get in a hurry and force it. S****ey Devils C.C.
i did the same manifold before. i stuffed a greasy rag down into fitting then with my dremal cut it 1/8" above the manifold carefully removed the greasy rag. i have a flexible shaft for my dremel that i use to remove bearing races with mini-cuttoff wheels drop a magnet with a string attached (to collect up 99% of the metal shavings) and start making slice cuts until you can remove chunk with chisel or punch. slow method but works.
Does Helicoil make an NPT repair kit? I'v had good luck by damming up the area so Kroil can stay in a puddle. Shoot a little in every morning for 3-4 day's. Get everything blocked up so the intake - off the engine at the time - doesn't move, put a socket and breaker bar on it, get the big br*** hammer and give it an accurate and fairly firm hit. No wimping out. The penetrant and the shock loadiing usually get's it out. If you damage the threaded hole and it's beyond re-threading, make - or get from Earl's - an aluminum threaded weld bung, drill to suit and JB Weld the weld bung in place. Unless you prefer to weld, but if you're careful you can JB it in with no epoxy showing.
Lay a steel washer over plug Rosset weld washer to plug Then weld a nut to washer Allow steel to cool - the aluminum will act as a heat sink Now Heat the aluminum to expand the tap'd hole & wrench out plug. & Heli coil does make NTP kits.
I have had great luck using Kroil to free up everything. Put the Kroil on and get a 6 point socket and a breaker bar, tap the breaker bar with a hammer, not hard. Let sit, hit the breaker bar to the left and right, this will help the Kroil work its way down into the threads. It's not fast, but it works.
On the drilling: I've had several stuck plugs suddenly become easy to remove after drilling the first couple of sizes while sneaking up on the thread diameter. Apparently they relax a bit in size when the center is drilled out.
Here's another thought: Many machinists like straight kerosene for a penetrant. Recommendations usually being soak it for a couple days to a couple weeks. I left a 10" South Bend tailstock immersed in kerosene for one year. Only meant to leave it in for a couple months, but it got p***ed by several times etc. The tailstock had been out in the weather from about 1993 to 2004. When I pulled it out, things that were rusted solid were moving although with difficulty. A little PB Blaster helped free it up all the way. Strangely enough, the kero removed quite a bit of the surface rust and the tailstock is to the point where a little more work would allow it to be painted etc....
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