Aftermarket head studs are vital for high-performance engines with high compression or turbochargers, both of which experience extremely high internal cylinder pressures. ARP studs are a popular upgrade in automotive racing engines, and are proven to be more durable than OEM head bolts. Here then are some quick tips on how to install them.
1. Inspect the holes in the block and remove any dirt or oil residue if present. Use brake cleaner and a wire gun barrel brush to clean out the holes in the block to ensure all the studs go in the same depth. The head studs will feed back incorrect torque readings if there are any traces of oil on the threads.
2. Apply ARP moly-based thread lube on the wider threads of each stud. This is the threaded side that does not have the hex head on it. Finger tighten the stud into the block, then proceed to use a hex bit to bottom the studs out against the block, making sure not to over-torque the studs.
3. On about 50 percent of head studs, you might experience some hard spots threading them in, even though the holes were perfectly clean. Don't be alarmed-this is perfectly normal. After getting by these tight spots, the studs should continue to go right in with no further problems. It is very easy to tell the difference between hard turning and a stud that's bottomed out, as it will come to a very firm stop when you hit bottom. If the studs are difficult to turn, immediately stop the process before any damage can occur and simply remove the stud and reinspect the holes for any debris.
4. An easy way to ensure each stud has been properly seated is to use a dial caliper to measure from the top of each head stud to the block deck. All should be the same length.
5. After scraping all the old gasket material off the block, clean the deck surface once more before laying on the head gasket. Be careful not to gouge the cylinder heads during reassembly by dragging them across the head studs.
6. The final step consists of following the engine manufacturer's torque pattern when installing the head(s). Be sure to double and triple check your torque specs upon completion.