Head Studs

[Flicky]

I was wondering if anyone has looked into getting custom head studs made from someone like ARP. I know the stock setup is with bolts, but I'd like to do studs for the turbo. I see that DPI has a set, but I don't know the details like if they are a cross-over from another engine or the specs such as tensile strength. I'd prefer to know they are made with a high quality alloy like 8740 chrome moly.

Does anyone happen to have these specs?:

thread diameter and pitch
thread length
overall stud length
washer outside diameter


If there are others interested, then it might be possible to do a group buy and get it to around $200 a set.

[dustybarn]

I discovered while replacing a worn rocker arm that my car has head studs rather than bolts. I believe they may have been installed by Ben Byrd's Scientific Automotive back in the 80's in conjunction with the turbo installation, but I don't really know. I wish I knew whose studs were used.

I do believe that using studs rather than bolts may reduce the risk of damaging the threads in the block, but you're on your own in determining the right torque setting.

Another thing I noticed on my engine is that the recesses in the block where the head bolt holes come through, are filled with what looks like Moroso engine epoxy. I believe this was done to prevent oil that makes its way down the stud from weeping out.

[David T]

I discovered while replacing a worn rocker arm that my car has head studs rather than bolts. I believe they may have been installed by Ben Byrd's Scientific Automotive back in the 80's in conjunction with the turbo installation, but I don't really know. I wish I knew whose studs were used.

I do believe that using studs rather than bolts may reduce the risk of damaging the threads in the block, but you're on your own in determining the right torque setting.

Another thing I noticed on my engine is that the recesses in the block where the head bolt holes come through, are filled with what looks like Moroso engine epoxy. I believe this was done to prevent oil that makes its way down the stud from weeping out.

At the levels you can run a turbo at there is no issue with the clamping force on the head gaskets. The original bolts are sufficient. If you do use studs you may not be able to get the heads on and off with the motor in the car. If you are worried about the threads in the block install threaded inserts (Heli-Coils). If you go with studs you are on your own to determine how to torque the nuts on the studs.

[Delorean Industries]

Custom made exclusively by arp for us. Used on every build regardless of mods now.

[dustybarn]

At the levels you can run a turbo at there is no issue with the clamping force on the head gaskets. The original bolts are sufficient. If you do use studs you may not be able to get the heads on and off with the motor in the car. If you are worried about the threads in the block install threaded inserts (Heli-Coils). If you go with studs you are on your own to determine how to torque the nuts on the studs.

I had forgotten about the clearance issue. I did have to pull the studs out of the block after removing the nuts in order to remove the head. A nuisance, but manageable.

[Flicky]

Custom made exclusively by arp for us. Used on every build regardless of mods now.

Ah, well that makes it easy. Thanks Josh!