Intake studs vs Exhaust studs - General Question

[marshallnoise]

On my m30 swap, I have to replace the exhaust studs on the head. The spare head I have has a nice clean set of intake studs that I want to install on the good head where the exhaust studs were.

Looking at the part numbers, there is a difference.

Intake Stud: 07129908135 M8x50
Exhaust Stud: 07129908134 M8x40

The intake stud is longer by 10mm. This is not a huge deal at all. However, the material that the intake studs are made of look like aluminum while the exhaust studs looked to be steel.

Is there a problem with running aluminum studs where steel studs used to be on the exhaust side?

[IronFreak]

I can't give a technical answer but I'm assuming BMW did it that way for a reason.

[marshallnoise]

I can't give a technical answer but I'm assuming BMW did it that way for a reason.

I am doing lots of interwebz searching and yeah, the only alternatives are stainless steel or hardware store stuff. I am betting that aluminum, when in stud form, can't take the heat as well as steel.

But since the head is made of aluminum...I suppose aluminum valves and aluminum valve seats and springs and stuff don't exist. Maybe I am over thinking this. :loco:

Oh well.

[slammin.e28]

Intake studs are intake studs.

Exhaust studs are exhaust studs.

[IronFreak]

You're Welcome

This is where I bought all my studs. Save you some money and super fast shipping.

[AndrewBird]

They are the same, only different lengths. ALL of them are steel, NOTHING on the engine in the way of fasteners is aluminum. A threaded stud is a threaded stud.

[MR 325]

What's the issue here? Buy new OEM studs. They are $1 each for the intake and $0.50 each for the exhaust...

[marshallnoise]

They are the same, only different lengths. ALL of them are steel, NOTHING on the engine in the way of fasteners is aluminum. A threaded stud is a threaded stud.

If so, I will reuse the intake ones then. I will test the studs with a magnet. That should be the end all.

MR 325, I agree. Not expensive at all. But why spend any money if you have a scrap head you can salvage the parts off of for free?

[Project535]

I have extra studs from a head refresh I did on my E28 (M30B34) that you can just have. PM me if you want them.

[marshallnoise]

Thanks Project535! I will pass on the offer. I verified what AndrewBird said and they are steel so I will be reusing the ones from my bad head. Thanks for answering the questions!

[mr2peak]

I believe the M54 ones will fit, and they have provisions for an allen key to tighten/loosen them

[lambo]

I believe the M54 ones will fit, and they have provisions for an allen key to tighten/loosen them

I'm definitely going to look into that for when I replace studs. That would be super handy.

[ccsdo5]

You're Welcome

This is where I bought all my studs. Save you some money and super fast shipping.

This place rules I've literally ordered something on a Monday around 4pm and had it on Tuesday.

[jrobie79]

They are the same, only different lengths. ALL of them are steel, NOTHING on the engine in the way of fasteners is aluminum. A threaded stud is a threaded stud.

just for clarity, I believe the exhaust manifold nuts are copper, if not copper they are definitely a different color than standard deformed thread nuts

[SkiFree]

The exhaust nuts are copper plated steel ... the intake studs and valve cover studs are zinc plates steel.

Couple pictures here when I redid my head with new bits (including the hex head exhaust studs).

http://www.r3vlimited.com/board/showpost.php?p=4327787&postcount=234

One last tip is to use the 11mm thin intake nuts, they're much easier to get a handle on with your manifold in the way.

http://www.iemotorsport.com/bmw/2002-fuel-intake/M10.html