No thanks. I'll stand by my statement that I would rather weld a proper bung on there. I like having an EGT.

I still would have gone to Home Depot and spent $.12 on a normal tapered NPT plug. Maybe add a little bleach to increase oxidation and screwed it in there and let it rust itself sealed. :P

Maybe a piece of bailing wire or two to make a champagne cork cage to keep it there just in case.

LOL @ Dean. It's stripped good. The plug would not have bit. I didn't know bleach causes rust. Should I coat the threads of the bolt with that before screwing it in?

I like having an EGT too, but the probe is fried and they don't make replacements. I'll probably search around to see what others with the Omori EGT gauge have done. But it's in the wrong manifold so I'll tap the driver side if I do end up getting a replacement probe.

Bleach is an oxidizer. Spray some on your brake rotors, they will rust in minutes.

If it wasn't upstream of the turbo, I'd suggest throwing a couple pieces of bailing wire in there to act like wooden matchsticks in a wallowed out wood screw hole. :P

What do you think's holding it in there now?

I'll tell you one thing, I'm definitely losing less exhaust out through the probe now than I was through the UP gasket I just replaced. The car feels much more responsive (and sounds better too). :cool:

Wait.. so you're going to ram an SAE threaded bolt into an NPT hole to try and plug it? Am I reading this right, or did I get confused (entirely possible) somewhere along the way? If so, that is a Bad Idea. NPT holes need NPT plugs.

And don't worry about bolt/plug grade, this isn't a structural application and I assume very little torque will be put on the fastener, so it doesn't much matter.

No the the bolt I'm using will match the newly cut threads in the manifold perfectly.

The only reason I went with grade 8 is because I was concerned with thermal expansion and had no idea what grade would be best but all of the OEM fasteners on the manifolds are grade 8 so I figured it couldn't hurt. Obviously cost wasn't a concern at $3.22. :P

Okay. FYI the bolt grade will not affect thermal expansion. You only need a certain grade if you need to develop a torque requiring its strength.

Well, then I wasted a buck. Hopefully the guy at R&E was right and I'll be able to cut the bolt with a cut off wheel. Should I consider a lower grade bolt or should a cut off wheel work. I have dremel cut off wheels and an angle grinder.

An angle grinder with a thin cutoff blade will work just fine. You need a metal cutting blade for whatever size grinder you have, you can get it at any hardware store.

I bought "cut-off wheels" for my angle grinder and they worked fine for cutting open struts for Koni inserts. Those should work eh? Or do I need an extra thin metal cutting blade?

They're fine, just don't rush it. You might want to make sure you have the reinforced kind though, or you'll go through like 25 of the crappy discs by shattering them.

I don't think they're reinforced.

What do you guys think about spraying some high temp copper gasket spray I have on the bolt to help it seal and stay in place? Too hot to matter?

The one I have here in front of me is .040" thick, but anything rated for metal will work. You could use a thick grinding wheel if you wanted, it'd just be extra ugly and you might have to do more cleanup on the threads.

Gotcha. Should I leave the bolt bare or spray it with high temp copper gasket spray before installing it? Can't hurt right?

I don't know what temp the spray you've got is rated for, or how hot the manifold casting gets during operation, so it's hard to say. My concern would be goop melting away and doing something to the turbo, but I dunno if it would be an issue or not. You might want to try finding a copper crush washer that will fit the bolt instead, to be your sealing surface, instead of gooping some spray in the threads.

I think what I'll do is only use the copper spray on the threads that are closest to the head of the bolt and on the washer. I was wondering if a copper washer would be a good idea given the heat involved. The guy at R&E recommended one but had no idea if it would melt.

This may officially be the longest thread on the internet about your bung hole, Cody.

....wait, nevermind, there's that other thread on that other site I almost forgot about.

For god's sake, plug that damn hole already and see if it works... more talking about it isn't going to get you any closer to being leak free!

Copper has a 1900+deg melting point, so I'd say it's worth a shot.

Awesome. If the exhaust gasses are only ~1600* hot the metal should be cooler. I'll definitely use a copper washer then, maybe one on either side of the grade 8 washer and then I might not even need to cut the bolt. I'll play with it.

I would not use any "spray" or a copper washer. With goop of most any flavor, the carrier will carbonize.

Copper washers may not melt, but the become quite soft and deform at forced induction temps. I tried copper gaskets and they were far worse than the OEM steel from a leaking perspective.

Agreed on the copper gaskets. The one I had between the UP and PS Ex. Man. lasted about a year before it blew out and looked like a volcano. Then the one I had between the Ex. Man and head started leaking shortly after. What a headache.

However, gaskets are exposed to the exhaust gasses while the copper washers will be on the outside of the pipe where, I imagine, it's much cooler.

They expand and contract at a different rate than the steel around them. that is what loosens things and causes leaks.

Did I mention I'm going to have a rabbi bless it first?

Yah, I dunno. Too many options and it's not my expertise so I guess I'll just stick with the original plan and just use the single grade 8 washer. I'd like to at least coat the washer with the copper spray, but I'll have to read the can first and see how high of a temp it's rated for.

I can't believe it took 69 posts before someone made this joke. :lol:

I know you guys want to talk about my bung more.

I've decided that whoever suggested that I just go to the next size plug was right. (Dean?)

I've got a 1/4-19 Pipe tap and a 1/4-18 Pipe tap. I just hope that the material that the plug is made of can withstand the temps. The plug I saw at true value for the existing hole size appeared to be solid, so that's good at least. Any plug that's not copper should withstand the temps right?

PS: Dean, good idea. Rebooting the BBQ fixed it. I think I need to be sure to open the valve on the tank before opening the valve on the BBQ to avoid it in the future.

A steel or iron plug will be fine in a tapered pipe thread joint.

A straight threaded hole using a regular bolt needs a sealing washer between the part's outer surface and the bolt head. If that washer softens up because of the temperatures involved, then the joint loses preload and will eventually leak and loosen up. All this depends on the specific temperatures involved. Copper crush washers are used routinely on cast iron brake calipers that obviously can get very hot during operation, but a hot caliper is probably still quite a bit cooler than an exhaust manifold. So, I dunno. Might work, might not. Hard to be more specific over the internet.

Yah, that's the issue. The "casting button" (raised bump on the manifold that is thicker than the rest of the pipe) where I tapped the original hole years ago is not wide enough to provide a flat seating surface around the larger hole I had planned to tap for the straight bolt. So by the time I tapped the larger hole, the casting button would be almost gone and I'd probably have to grind it off completely to create a flatish surface for the washer[s] to seal.

Obviously the tapered pipe thread is an effective way to seal or EGT probes wouldn't have been designed to utilize one. I figure I just need to secure a plug that won't melt, and I'm in business.

Thanks ALM I'll call True Value to see if they have a plug made of iron or steel on my break since they're on my way home from work and open in the evening. I'd rather not take another long lunch to go to R&E.

All Pipe plugs you will get at any "hardware" store will be steel and be fine at those temps. Brass would also work as that is what the EGT compression fitting is made of.

Yes, that is why they use pipe thread. the thread itself is the seal due to the taper.

Ahh. Yeah, a crush washer will not work. They are used in conjunction with a smooth, flat surface perpendicular to the hole's axis. You would not be able to create one smooth enough with a grinder, they are normally milled out.

That's what I figured, plus I wouldn't want to grind away at the pipe. :eek:

So True Value has a 1/4 NPT plug for 79 cents (:lol:) and all the guy could tell me is that it's "black pipe". He was actually a real asshole over the phone to me. I asked him what the thread pitch on it was and he said, "I dunno. I don't know what thead you're using." I said, "Well, it's NPT right?" and he said it was so as long as "black pipe" metal is okay, I'll grab it on the way home and FINALLY plug my bung!

Black pipe is fine. It is probably damn close to the steel the header is cast from.

Pick up one for your current size as well for $.79. You never know, the taper on it might go further out than your egt. Depending on the head on it, you might drill a cross hole in it and put a piece of safety/baling wire through and around the header for a while.

Don't over tighten a tapered thread. It it has enough bite, it might split that button in half.

Hmmm, redneck safety wire, I like it. :lol:

I certainly won't be overtightening it. That's what got me in this mess in the first place.

That's when you say "eeeeeehhhhhhehehehehehehehhheeeeehhhhhhheheheh... ..I need NPT for my bungholio!"

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:lol: :lol: :lol: :lol: :lol:

HEY! You just got 1995 all over my 2009!

:brill:

Think a brass plug would be okay (lower melting point but less thermal expansion) or should I drive further for a black pipe plug? Afterwork plans changed so now brass at home depot is closer.

OMG, you lazy SOB...

Brass might be a better choice if you plan to put the EGT back, steel if not. The former will not rust, the later will.

LOL, brass will save me 12 miles and 20 minutes of driving.

Ace, 5 minutes from here, has galvanized and brass. They're like twice as expensive as True Value though! :o

Is galvanized okay better than brass?

Dude, your bung hole is high maintenance.

My mom used to go to a bar called The Brass Ass when I was a kid.

Galv = steel, just like the black only coated differently.

Which one is on your way to the meet? :P

Ace is, but unfortunately I have to get my hairs cut and then get home and plug my bung and pack my travel bag. :lol:

I'm going to friggen close this thread and make Cody PM me when he finally has his bung plugged and then I'll re-open it so he can write 40 posts on how he finally figured out how to put a screw in a hole.

Righty-tighty right?

Jesus, I'm looking forward to Cody's nine page oil change thread

You mean the one where I removed the Fumoto oil valve and cut a groove into it and then measured how much oil it still held back? We talked about Royal Purple and all sorts of stuff. Good find.