The washers won't work because they'll get hot, **** will stretch, and they'll deform. It won't work. But...I know something you don't, lol.

 

Iam speaking of the mani/turbo flange,I first lapped it on a granite plate to 600 grit then polished with a fine stone.the flanges are dead flat,with an even nondirectional finish.mymanifold flange is 9/16" thick,FYI.
-G-

 

Inconel won't work, it doesn't have the coefficient of thermal expansion you need. The hardware I'm trying to get but can't find a good source for I seem to not be able to do without a 20000 dollar order. Even if I got the parts in they would easily be a 100 dollars for 4, and the only size I can currently get them in for a 100 dollars for 4 is standard.

 

Please share! Save me the time and money!

Joe P's already talked about Belleville spring washers. They can use Inconel and other high temp materials. The high temp versions are supposed to handle tens of thousands of cyclings. They are used in military, industrial and aeronautical applications where temp cycling can cause loosened connections.

Sounds like our problem doesn't it?

 

What cueball1 said.

We're talking about a conical spring washer that's specifically designed to deal with thermal expansion of very hot flanges. I think I posted the specs earlier; the high-end ones are rated to like 700°C or something ridiculous like that. Until somebody actually tries a set of them (properly installed) and still has studs coming loose, I really think they sound like a viable solution.

 

If there are no final non-V-band solutions yet, I'm gonna do this:

1) Use 8mm SS studs
2) Use these fancy SS nuts from APT
Aircraft Quality Turbo Lock Nut, M8 x 1.25 - 034 MOTORSPORT
3) Use resbond on studs and nuts
4) Cinch the studs with Matt's stud driver thingy
5) torque the nuts to just 10 ft-lbs
6) hope the SS studs allow more stretching than the usual crap

Anyway I'm not after spec miata records.

All we need now, is SS M8 studs. Where do I get 'em?

 

BTW where can M8 belleville washers be purchased in the US?

Are any of them spec'd for high temperatures?

 

I do not stock SS 8 mm studs, but I can get them. They are available in 304 and 316 stainless.
Stephanie

 

Anyone with ASTM access?
ASTM A193 / A193M -09 Standard Specification for Alloy-Steel and Stainless Steel Bolting...

 

glow color vs temperature

Temperature when metal glows red | Hearth Wiki

Looks like we need hardware good to at least 500°C

°C °F Color
400 752 Red heat, visible in the dark
474 885 Red heat, visible in the twilight
525 975 Red heat, visible in the daylight
581 1077 Red heat, visible in the sunlight
700 1292 Dark red
800 1472 Dull cherry-red
900 1652 Cherry-red
1000 1832 Bright cherry-red
1100 2012 Orange-red

 

Hmm, this pages suggests that 316 has a higher yield strength
Guide to Buying Stainless Steel Online | Online Metals Guide to Selecting Metals for Your Project

and these pages say that 316 is better suited at high temperatures, is more corrosion resistant at higher temps, and has the same Young's modulus as 304:

Stainless Steel - Grade 304
Stainless Steel - Grade 316 - Properties, Fabrication and Applications

How much for the 316 studs?

 

ASTM A193 high temperature fasteners grades B5 B6 and B7 are for high temperatures
American Fastener - ASTM, SAE, and ISO Grade Markings

and McMaster sells em
McMaster-Carr

Surprise, grade B8 is 304SS, grade B8M is 316SS:
Material Specifications

 

I will sell them to you at my cost, plus what ever freight I am charged. If you wait until I have another order from this supplier, no charge on incoming freight. I did call on these studs. They are $6.00 each, and would have to be made. They are not in stock. They also have those spring washers you wanted too.

Stephanie

 

I can check at work to see if we have M8 tap ends in 316.

I work at a fastener manufacturer, so I should be all over this...but I'm chasing other problems and still haven't seen a trackday.

If Travis would let me know what he's looking at I can see what we can do. We are a specialty fastener company...that's what we do:

Specialty Flange, Fasteners, Seals and Forgings - Lone Star Fasteners

We mainly deal with oil service companies...but we have a huge inventory, and I've seen <$1000 custom jobs for a 4" x 4" x 4" box quantity before.

I'm pretty busy with school work, but can do some homework. Let me know what you'd like to find (without having to read the whole thread). I was under the impression the actual fasteners weren't the problem....

 

I got my fasteners supplier figured out. I'm going to see if I can get engineering samples first to test. Price will be about 139.00 shipped. Its the best hardware in the world pretty much. I checked 50 grades of stainless and sorted all the standard metal suspects and nothing came close to this performance. The catch is I have to have commitments to do this because the upfront order quantity is big.

You can put all the patches you want on this, but this fastener pretty well fixes all. It holds a 120,xxx psi at 1600 degrees compared to 316 stainless which holds about 12,000psi. Yes its 10 times as strong at high temp, and dramatically outperforms it all the way cold. This is especially made for high temperature stability, and it has the coefficient of thermal expansion that keeps up with the stainless flange.

 

Are you still talking on STD threads, or can you get it in the usual suspect, M10x1.5? If you can get the metric then you can count me in 100%

 

This is metric, that's why it is expensive. The first 15 quotes I had for this material I couldn't get the studs done in metric for less then $55 a piece and minimum order was ridiculous.

I'm planning on placing an order for M10 1.5mm thread pitch, and 1.5inches long and M8 1.5mm thread pitch at 1.5inches long. Does anyone know if these do not fit? Can someone send us your current hardware just so we can verify the lengths/thread are correct. THESE THINGS ARE STILL EXPENSIVE. A mis-order would put boundary out of business I believe.

 

40mm long, so the 1.5 inch long studs will work fine.

You could always order a single stud from ATP turbo, i believe they use 38mm long IIRC, i am currently using 40mm studs and they are fine. You could always call ATP/BEGI and ask too..

 

i'm down for the m8 size. if you can get them to me quick i can test in the next few weeks. i have a bunch of events coming up and it's still mid 90's here in texas. plus i have a built motor, heavily tracked car and run sub spec times. i should be doing 4 events between now and the end of oct.

 

https://www.miataturbo.net/forum/t39021/

M10x1.5 Inconel group buy. $100 a set. I will prove these on track before anyone pays me a dime, which means you get a pre-tested proven solution. If they don't work, we'll go back to the drawing board.