Porting iron P-car heads & whoops!

Got about 30 hours on the intakes went to do the exhaust, and then I seen em.. AIR PUMP PORTS.

So can they be epoxied? Or do I have to braze em shut? Also, just the outside ones, or the inside ones? Thanks.

Drill and tap the holes for a set screw that will sit below the flange surface. It's been a while since I did a set, but you might not have to drill if the hole size is right for tapping. Can't remember if it was 1/4" or 5/16".

The holes will take a 5/16th coarse tap. Thread them and put 5/16th set screws in them. I just did a set yesterday on the 360 going in my truck.

Thanks gentlemen

I have been doing the same to the heads that I have. I tapped 7 of them successfully using my 5/16 - 18 thread tap and then broke the tap in the hole on #8

I have now broken it off below the surface (it keeps crumbling) and resists easy removal. My next step is to use my Dremel and a tiny grinder bit to get all the rest of it out. I will use a proper pre drill bit and go up to a 3/8 - 16 tap on one hole in this head. Just a little hiccup in the process. I know better, I just wanted to hurry the process and it bit me in the A**

I too broke off a tap in my 302 heads. The AIR holes in my heads were about exactly 1/4". I found a 5/16" tap and found the proper drill bit, then drilled the first inch or a little more. Tapped to 5/16 - 18. I had a bunch of 1" Grade 2 bolts so I ran-em in as far as I could and cut off the heads. Messy but OK. I used a small punch to work on the broken off tap, then filled the hole, with the remainder of the tap still inside, with JB Weld. There's been no sign of leakage from any of the holes. I believe when the exhaust gases can't travel through, the holes carbon up pretty quickly.

I believe if you drilled out the holes so they were clean that JB Weld would be all you needed. In my case I had too many bolts.

R.

30hrs grinding intake ports on OE iron heads??? Yikes!!!
Noooooo thanks......

Just heat the broken tap with a cutting torch and and give it a quick shot of oxygen. The broken tap will instantly vanish.

Kevin

Cause I don't have your skills Good thing I don't charge myself labor

#1 of 8 lol. So like this? What about the hole inside the port? Leave it?

Heat to what color? Heard this before on removing broken studs and things.

I would do that if they were just cores and no great loss, but the heads had been through a machine shop, valves ground, PC stem seals on all valves etc. (the full treatment) are completely assembled and I don't want to heat the one and risk any further steps back. I will just get comfortable with the Dremel and work it out.

I grind the bump down and let it go. Just keep plugging the holes like you are.

I still have a few sets of iron heads leaning against the wall in my garage but so far I have been smart enough not to touch them. I hope I stay smart enough for the rest of my life so my kids can scrap them after I'm dead.

I just used spare/old bolts. Drill/tapped, bottomed them good, ground them off & flush. Buh-bye to dat. Those ports'll never get smog hdwr on any day.

If you break a tap off below the surface, screw getting it out as if you got a torch just fill it with braze, or clean and arc hit it with nickle rod.

Calling me dumb? Seems about right!

WAIT! I WAS right! Had a stop on the drill bit, and I hit water.. junk in 30 seconds.

Well well well well.. what's Summits # again?

You are killing me over here. LOL I'm trying to get ready for a Mopar race weekend.

Why didnt you just tap the existing small holes and use a smaller threaded plug?

The few sets of smoggers ive done I dont recall ever pre drilling, but I did break a cheap tap one time, just butsed it up with a tiny punch and it dumped out.

If you just jacked 30 hours work it might be cheaper to buy some heads, that iron material and dust isnt good for your lungs.

I sure did just jacked 30hrs of work.. in 30 seconds no less


Just followed the advice given to me. Put a stop on the drill bit to be safe and to avoid what just happened. In my younger days I wouldn't have taken this so well. LOL. Now it's:

"C'est la vie".

braze it up???

Braze it or put some threads on it. Smear JB weld over a piece of threaded rod with a screw slot on the end of it.

I'll try the JB weld. It's a small banana shaped hole at the very bottom. About double the width of a credit card looked edge on. Thanks.

I guess I'm confused.......the air injection hole goes all the way through.
How do you hit water like that ?

Way to learn😅

Gotta start somewhere.



Dunno. Drilled 5/16ths as suggested, boom water. Drilled the first two to the same depth, no problem.

That's what I'm wondering. If you are just cleaning the hole up to tap how did you find water?

You could have turned some stock down on a lathe and just pressed them in.

You are just plugging a a small hole.

That's what she said. HAHA.


Don't have a lathe unfortunately. I'll fix her up.

All you need is some 1/8" set screws. You don't have to plug the holes with plugs that large. I didn't even have to drill my heads. I just bought a new tap and went at it.

Good luck with the plug. In cases like this JB Weld is your friend.

I don't believe anyone said drill with a 5/16" drill bit. I did say to use a 5/16" tap and drill with the correct size drill bit. This info used to be stamped right onto the tap shank. I only drilled as far as the tap would go in. In your case it illustrates that blocks weren't the only thing to have core shift.

I am convinced that once the AIR hole is cleaned out, filling it with JB Weld would keep things sealed up for the rest of time. So that's what I'd do with the hole in your cylinder head.

R.