Head studs

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937carrera
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Re: Head studs

Post by 937carrera »

That's good info, I was just updating my post to add the detail about type 1 fitment as you posted.

The WBX has dome head nuts, so are you simply going to use washers to space the nut away from the head where the stud is longer or cut the stud. What will you do on the shorter studs ?

On the Mecatecnic site there are also listed the case repair studs, looks like they drill the M12 to M14 to allow the M10 stud to fit. Any chance you could put up a photo of your case ?

It might be possible to get a thinwall repair piece to allow an M12 thread in the M14 hole. From an engineering perspective VW moved from M8 to M10 and then M12 on the case side as the engines grew in size and power. I would have thought that the larger thread diameter provided greater strength against threads being pulled out, so the question is can you / should you go back to stock diameter on the case side ?

Here's the Timesert alternative http://vwparts.Aircooled.net/Time-Sert- ... /10155.htm
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bigbadbob76
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Re: Head studs

Post by bigbadbob76 »

If both ends are 1.5mm pitch, could you turn down the M12 end and cut a new M10 thread on it?
I'm tempted to go this route on mine.
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937carrera
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Re: Head studs

Post by 937carrera »

You might be able to do that, but someone (a proper engineer, not me) would need to think about the stress relieving where the thread meets the stud.

It might cost as much as putting a Timesert in, and then you would be back on standard parts, and availability.
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itchyfeet
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Re: Head studs

Post by itchyfeet »

937carrera wrote:You might be able to do that, but someone (a proper engineer, not me) would need to think about the stress relieving where the thread meets the stud.

It might cost as much as putting a Timesert in, and then you would be back on standard parts, and availability.

I'd agree risky unless you are a metals expert, you have no idea how there are made and treated to withstand the stress they are under.
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itchyfeet
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Re: Head studs

Post by itchyfeet »

I have asked of the FB WBX group for you lets see what they come back with.
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Re: Head studs

Post by tobydog »

937carrera wrote:You might be able to do that, but someone (a proper engineer, not me) would need to think about the stress relieving where the thread meets the stud.

They look like they're waisted down below the core diameter of the M10 thread, I don't think there would be an issue of stress as a result of the transition from the turned and re-threaded down portion, as long as they're screwcut with the correctly profiled tooling (thread root radius). I think the hardness might be more of an issue depending on tooling available. Try one to see how it goes?
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937carrera
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Re: Head studs

Post by 937carrera »

BBB has successfully removed his helicoils and the original M12 x 1.5 threads seem intact so going back to standard studs is viable for him,

bigbadbob76 wrote:And they're out. I was being too carefull. Haha. A sharp screwdriver hammered down the side of the first thread got it to stick out enough to grip with the needle noses.
A quick check with a tap proves they are M12x1.5.

Image

http://forum.club8090.co.uk/viewtopic.p ... 4#p8218113
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Re: Head studs

Post by robinsbw »

The head studs are are class 10.9 Alloy steel,quenched and tempered. The threads are rolled on at the first stage of production for greater strength. The turning down and threading cannot be done as the studs are too tough.
The studs that are too long I'll cut equal amounts off either end with a angle grinder that has a cutting wheel. those that are slightly short I'll check the depth of thread in the domed nuts and not screw into the case full length.
The removal of case nuts doesn't seem correct as the threads may have stripped or been damage before.

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