alunox exhaust manifold installation.

[stormy69]

thanks Travis, is that m8 x 1.25? and the length?

[sailorbob]

The exhaust manifold to cylinder head studs are M8 x 1.25 x 41 mm, A286 grade I believe.

[DJ Bob]

I'm assuming this is a support brace and bracket. Where do they attach?

[jcslocum]

The plate will mount across the back of the cam towers, with the 4 bolts holding the caps on. The strut will mount between the 2 tabs on that hat bracket and then to one of the threaded holes on the side of the turbo mount.

 

Edited September 27, 2016 by jcslocum

[Zig]

To further relive turbo weight stress on headers I decided to add another header support turnbuckle referenced to two transmission bolts.  It will utilize the spare attachment point ALUNOX machined on turbo flange and utilize a custom bracket..

ALUNOX header to bell-housing mount support - parts...

 

Spherical bearings from UK:  

M8 X1.25mm Male Rod End Rose Joint Right Hand Thread 8mm Bronze Liner MMSAK8B

( 161231127784 )

M8 x1.25mm Male Rod End/Rose Joint Left Hand Thread 8mm BRONZE LINER (MMSAKL8B)

( 161257865667 )

 

316 Stainless Steel M8 Turnbuckle from China:

(Will shorten turnbuckle if necessary)

316Stainless Steel Closed Body Jaw Jaw Turnbuckle M5 to M16

 

Header support studs:

http://www.ebay.com/itm/200893751675

Any 316, 324 or Inconel M8 1.25 stud will work, but I liked this set... These 316 stainless studs are a good starting point to have them machined to fit 8 mm rod bearings.  The 316 studs I picked allows for tightening stud to the header using the hexagon surface it incorporates. This surface will allow me to use a wrench to hold and prevent the stud from rotating when removing or installing the nut holding rod end in place.  Preventing stud from unscrewing or over tightening will save manifold threads from thread galling and possibly seizing, which is the common problem when using stainless steel to stainless thread surfaces. 

The 10 mm step I will re-machine down to 8 mm to perfectly support rod end. By leaving short 10 mm spacing step at hexagon surface and slightly angle cutting hexagon I will be able to create a gap which will allow tie rod head to rotate freely. 

Ordered all parts today.  Prices were great...  less than $35 total!

Zig

 

Edited September 28, 2016 by Zig

[MarkKassim]

I've found some notes from previous GBs hope this helps

This is the Stevens Fitted with Heat Shield

This applies to G Car and Stevens:

1. The pipes rotate in the collector so you need to align them before you fit. Bolt the new manifold to the old one to ensure alignment.

Do not panic too much as most of the alignment needs to done on the car.

2. Remove or push to one side the turbo.

3. It helped me to remove the engine mount and raise the engine by about 1 inch

4. Pull the hand brake cable back out of the way, helps getting manifold in place.

5. Remove the heat shields, all of them.

Getting manifold in place......

 

1. Push the turbo flange end of the manifold up past the exhaust flange then guide the other end into place.

2. It's more than possible that all studs will not align, start with one end, closest to the timing pulleys, get the nut on the last stud, even if it's just one or two threads.

3. Work alone the top row guiding the flange on each port into position, I needed to use a strap just to align the flange.

4. Fit all nuts and loosely tighten. The new nuts don’t require tab washes as they are of the self locking type

5. Follow changes instructions re tightening diagonally, nip up, then tighten, do not over do it.

6. Once you have fitted everything else back on run engine on tick over only then let it cool, re tighten nuts, I suggest that after 100 miles the nuts should be checked and tightened as necessary.

 

In addition to this for people running the External Wategate , i.e all the G cars and some of the Stevens

You will need to modify the heat shield slightly where the pipework clashes . Cut or bend

The threads in the Turbo flange where for the machining process and the lock nut and bolt configuration should be used as shown.

adjust the brace so it is loose not taking the weight of the manifold, its for shock loading . The manifold will support the wight of the turbo easily.

Hope this helps ,

Mark

[MrDangerUS]

On 12/09/2016 at 04:47, Loose Cannon said:

Hi all, just a quick query - I have read on these various manifold threads that Aerotight nuts are not as highly heat rated as K-nuts which was a surprise.

I actually bought Aerotights in preference to the M6 oval manifold nuts supplied with the kits, which looked a bit cheap and flimsy.

Can anyone confirm if the supplied bright aluminium oval nuts are genuine K-nuts? They look a lot less "industrial" than the ones pictured on the K-Nut website thus;

Q. Should I be swapping the Aerotights immediately or just see how they get on?

The silver K-nuts (also called Jet Nuts) have different metallurgy and are real Silver plated. They have an advantage of 10mm hex, which enhances installation!

M8 Aero Nuts  have hex size = 13mm = more difficult to install.

[Barrykearley]

I’d recommend getting both studs and nuts from alunox. 

I had some crap studs supplied from elsewhere - and locking nuts - binned them off when one sheared on nipping up. Don’t be tempted to try getting a cheaper or an alternative option - alunox have sold lots and lots without issue

[MrDangerUS]

On 28/09/2016 at 12:15, MarkKassim said:

I've found some notes from previous GBs hope this helps

This is the Stevens Fitted with Heat Shield

The threads in the Turbo flange where for the machining process and the lock nut and bolt configuration should be used as shown.

adjust the brace so it is loose not taking the weight of the manifold, its for shock loading . The manifold will support the wight of the turbo easily.

Hope this helps ,

Mark

Mark,

Very informative thread, thank you.

My turbo flange has four holes with M8 thread. Are you suggesting drilling them out to accept M10 bolts?

Isn't it easier to install M8 studs using existing status-quo?

 

Edited March 12, 2021 by MrDangerUS

[MrDangerUS]

Everything is cool!

My calipers were off, not zero-ed properly. "Problem" gone! Sorry for panic.

[Chillidoggy]

@MarkKassim

With reference to the originally supplied turbo 'support brace', one of the rose joints broke fairly early on, due I suspect to heat cycles. As I'd always thought the brace was an unnecessary addition from my engineering viewpoint, I removed it.

Since then the car has covered 20,000 miles without any issue. That is to say, my turbo has not fallen off, and there has been zero broken studs or bolts.