Paging inconel stud crew
 

Because my inconel studs are backing out with just street driving. The car has not seen the track yet. Removed them, put MORE resbond on them, and they still came out.

Obviously the studs are not the problem, I'm trying to figure out what is.

Do you guys who have inconel studs have it coupled with other anti backing out measures? A couple things I could think of:

-A manifold where the studs don't see direct exhaust.
-Is your downpipe supported in anyway, like the stock one with the bracket that bolts to the tranny?
-Do you have some kind of mount to support the turbo?

My setup consists of a begi log manifold, downpipe that is not bolted to the tranny, and turbo is not supported by anything.

Opinions/ideas/name calling?

I'm going to swap out manifolds with another begi piece and see what happens, but I'm not keeping my hopes up.

Custom manifold, studs do not see direct heat. I'm not using resbond or locking hardware, and have not had a single problem street driving.

I haven't got my turbo setup installed yet, but after having a good read through the EPIC nuts/studs loosening thread this is what im installing.

I tapped my Begi manifold out from 8mm to accept M10x1.5 Inconel studs, some Resbond 907TS threadlocker, and Stage 8 fasteners. From what others have said about this setup I hope I shouldn't have a problem.


https://www.miataturbo.net/attachmen...ine=1329021449

^ you are installing my exact setup. Realistically, you shouldn't have any problems. I'm just unlucky and/or doing something very wrong here.

On my install (street driven so far, ~10K miles turboed), I discarded the studs and used 8.8 bolts drilled for safety wire. I used Inconel safety wire. Haven't had any issues.

I'm curious why everyone uses Inconel studs with locking nuts rather than Inconel bolts? Obviously, if you could use Inconel bolts with safety wire, you would be all set. Studs + Resbond + Fancy Locking Nuts sure looks overcomplicated to me. As you've discovered, studs can back out.

Don't know whether drilled Inconel bolts are available or whether they can be drilled without using some kind of special bit. Maybe that's the reason?

The studs are custom made too, so having to customize bolts by drilling safety wire holes shouldn't be a problem. Bolts will back out the same as studs, I believe studs were chosen because the stage 8 locking hardware is easier to use than drilling a hole. Plus studs are cheaper to manufacture than bolts.

OP, you are or are not using locking hardware along with your resbond?

I am, I'm using exactly what green_comet is using. Along with resbond.

It's not physically possible to install bolts into at least one (possibly two) of the holes on a normal T25 turbine housing. Also, using Inco safety wire on steel hardware is like rearranging the deck chairs on the Titanic. ;)

Abe, didn't we chat on the phone about this a couple of months ago? You said the studs wiggle in the threads even with almost all of the threads engaged in the manifold? I am pretty sure the threads in the manifold are your problem.

This is what I was about to post, as I've experienced this on one of the cheap cast manifolds I had - which ended up stripping the bolts (not inconel) and manifold threads. Can OP heli-coil flange without experiencing any thermal expansion issues from the helis?
FYI, I've tracked TSE's kit without ANY loosening - which is freakin awesome not dealing with it...

I'm a little worried you guys say that, I just checked the studs in my manifold and they all wiggle around a little no matter how much thread is screwed in. They lock up when they bottom out, but other than they they wiggle around a little.

Which is why I hope this second manifold works.


Any more info about your setup? Turbo/downpipe brackets/mounts, etc?

This is exactly how mine are. They're tight when they bottom out. I'm seriously hoping sav is right.

I'd rather see Inco bolts myself, scratch the locking hardware, and EDM drill.

That would be cool but it would be physically impossible for me to use bolts.

Hmm, I wonder if some manifolds are threaded with inferior taps. I know different classes of threads can have looser tolerances. Do you know what class thread your studs are made to Sav?

Because of the damaged manifold or something else?

I would only be able to fit a bolt in 2 of the holes, the other 2 would end up hitting the exhaust housing.


I'd like to know this too.

I'll ask Bryan's question again, since I'm curious. Any issues with Heli-Coils in this application? If not, there shouldn't be any problem re-drilling the manifold since you'll need to drill a larger diameter anyway. It sure sounds like your current threads don't have the correct dimensions.

Nobody here torques the studs into the mani after the shoulder seats? I do that with about 1/2 of the torque I use on the nuts, with a stud driver. This torquing also pre-loads the stud, in theory allowing the stress from the nut to distribute along the stud's threads.

I used a BEGI log mani before my ETD mani, and never had a problem with steel studs on the street.

To the OP, how hard do you drive on the street / Hwy 9?

I torqued the studs in. Probably with more torque than that. The torque specs on the instructions say to torque the nuts to 15 ft lbs. Would overtorque cause these to come out? (I'm not sure how but I figured I'd ask) Measuring 15 ft lbs with a wrench in your hand is kind of hard.

I stopped going on hwy 9 after my first track day :giggle:. I don't really drive that hard on the street, my commute right now is a total of 10 miles a day.

I got an idea too add. Anyone ever use time-serts? We used to use them for repairing stripped sparkplug holes and other things that heli-coils were just a bad idea to use them on. Link
http://www.timesert.com/html/mtrcsert.html
My boss had a dragster, don't know what motor anymore, with a couple of these holding the sparkplugs in. Lots of compression and supercharger. Never had issues with them because they replace al the metal you stud engages on.

ARTech taco clone, Garret T3 with SVO mustang housing (EWG), braced down low to PPF. My thread stripping happen on the cast Taco - but that was using G8 hardware. TSE kit was used when Abe fabbed me up the new manifold

No hard street driving and your studs loosen??

So, what's the difference between these and Heli-Coils? They look exactly the same.

Heli coils are basically like a spring coil of wire. The time-serts are actually a collar or a ring with threads on the outside and the threads you want on the inside. It comes as a kit with drill bit, boreing bit?, tap, and insert tool. You drill the hole out that is fubar'd, used the little bore bit to make the top of the hole shaped right, then tap it with the supplied tap. The tap that come with the kit is for the outer threading on the time-sert. Then you use the little tool for inserting it into the new shiny hole, not the virgin you found down at the movie theater, and the time-sert has a locking mechanism that locks it in the hole. Voala, new threads! You can remove the time -sert with reverse drill bits or an extactor, but they usually never come out with normal use. I never seen it anyway.

Heli coils suck. They're cool for fixing holes things mount to. Like alternator bracket mounts, to radiator stuff. I've seen them mangle themselves in the hole after use, and they don't really like a lot of torque. Some love them-some hate them. They are easy to use and can usually be done on a motor in the car. I wouldn't trust them on anything but a lemons car to hold in a spark plug though. Helicoils basically use a bigger, but same thread pitch as what is in the hole already, so if it gets bound up they come out with studs/bolts. Timeserts use a differnt thread and thread pitch, and have some nasty teeth things that bind in the hole they use. Think of timeserts as a hollow stud and helicoils as a bandaid.

Cool. I've never used time-serts. Need to check them out.

Ive used Timeserts on blocks and transmission housing and they are a million times better than helicoils.
The only issue here, would the timeserts hold up to the heat from the manifold? Ive never used them on an exhaust manifold so I would be worried that the heat would kill them.

Exactly. If I were to track the car right now I'm pretty sure the turbo would fall off.

The timeserts I was looking at were carbon steel. We used them to replace exhaust manifold to head stud holes with no issues. Also if it holds up to cylinder pressures/heat replacing spark plug holes I would trust it to hold a turbo on within reason. Never tried it. I'm overly ---- retentive to over building and I'd try it, especially before buying a new mani and way way way before Helicoils.

I looked at doing timeserts when I drilled/tapped my BEGi manifold for Trackspeed studs and decided that there wasn't enough material around the holes... there are multiple versions of the BEGi and FM manifolds though so YMMV.

Bolt the downpipe to the bellhousing?

This is what I was wondering about. Anyone experience more failures without this? I dont really want to do it if it's pointless.

All you're going to get is anecdotal evidence, since no-one has done precise durability testing with or without this part. I installed the FM exhaust brace a year or two after my build. Eventually one stock stud broke and another backed out, but the exhaust noise was negligible and the brace basically kept everything together until a repair could be effected (I now use Inconel studs). I think the theory is sound and it's pretty cheap insurance at $32 or so.

I put on a different manifold, same style, and the fit between the threads/studs is way smoother/snug.

I'm confident this will work but only time and a track day will tell.

What is the difference between the tse stud kit and the fm one? Just the lock tite?

it's resbond, much stronger than any lock tite available.

TSE is 10mm, FM is only 8mm.

TSE will tell you how much faster then spec miata times the cars they tested their inconel studs one, other companies have not ever released that data.

I think that's fairly irrelevant statement that doesn't actually answer the question asked. Blindboxx, the FM kit is better than stock and is plug and play if you have 8 mm studs. You can make it even better, like I did, by buying a bottle of Resbond and using it during your installation. If you have 10 mm studs, buy the TSE kit, which comes with a small bottle of Resbond. If you have 8 mm studs and want a stronger set-up, drill and tap for 10 mm studs and get the TSE kit. If you want the most robust set-up possible, throw it all away and get a V-band system.

To summarize:
Inconel > Steel
10 mm > 8 mm
V-band > Studs of either size or type

thank you for splainin that. and curley, i know i didnt call it the right name, i just didnt want to go look it up ;)

i was actually going to buy a precision v band in/out but decided against it since it was almost another 300 bones. i ordered this guy 2 days ago. so im assuming i'll need the 10mm eithe rway, and ive come to terms with the fact that im going to be poor as ---- when im done with this motor, but i'll sure have a cool car. so i wont sweat the extra 55 bones ;)


edit:
and i had no idea that these studs make your car 'faster'... why is that?

Lol, no, they don't make you faster.

Keeping the turbo sealed to the manifold makes you faster, or at least your engine more powerful, and they obviously have a part in that.

i guess i cant believe everything i read on here. :bowrofl:

V

The faster your car is, the more stress that goes into the studs. The point he's making is that if FM's cars were going as fast as TSE cars, 8mm might not be enough.

TSE has said how fast they're going, and that their 10mm studs are holding up.

FM hasn't said how much faster then SM times their 8mm studs were tested at, so it's a bit more of a risk. For the average Joe I'd say FM's 8mm are fine, and TSE's 10mm would be bullet proof peace of mind. In the end that's easily worth $55.

oh okay. makes a little more sense now. just the fact that TSE makes bigger ones and comes with thread locker makes the extra 55 bones justifiable (to me)...

i also sent an email to FM asking why they dont include thread locker in their kit and this is what i got back:


is TSE's kit made by ARP? my dad uses arp on teh race car everywhere and swears by them, so we gotta bust out the catalog and have a field day at the store.

Nope, they're specially made for TSE. Well, I don't think they're using ARP.

Our studs are not made by ARP. Our threadlocker (Resbond) also does not destroy the studs or manifold even when taking it all apart.

Parts installed with Resbond come apart with hand tools. It acts a lot like blue loctite, except that there is no way a mere mortal will ever deactivate it using heat.

sounds good to me! once i had found out your studs were bigger, you pretty much had me sold.