Existing: EngineQuest Testing Head Bolts


Hi, this is Joe from EngineQuest. I’m here to show you how we load test our head bolt and head stud kits. We have a load meter that we send out and have calibrated. We have a load cell that is hooked to the load meter, and today we are going to show you with an LS stud on how we load test for clamping force on the head gasket.

First thing, this is our LS head stud here at EngineQuest. We are going to install this, get an Allen wrench, make sure it is run down to the bottom, just a quick check that its down to the bottom. Then what we are going to do is we are going to install the load meter but we are going to torque it using these torque specs. This is the instruction sheet that comes with our head studs. Tells you everything you have to do so we are going to go off this sheet.

First thing, install the protection plate for the load cell. Second thing, install the actual load cell. Third thing, there is another spacer, or protection plate. As soon as you are done with that, you install a washer that has been lubricated on both sides. The lubrication lube that we use is MSP Performance, it is a Moly-type lube. That lube is also in the kit. Last but not least, you’re going to install the 12-point nut on the cylinder head, where it is just touching.

First torque is 35 lbs., second torque is 50 lbs., and the third torque is 70 lbs.. So right now we have the torque wrench set at 35 lbs., and we are going to bring it around. Ok, we are going to take that reading and register it. 723. Now we are going to take the torque wrench up to 50 lbs., and second torque, bring it around. There it is, 986. Register that value. Set the torque wrench at 70 lbs., bring it around; 1436.

Ok, so at this time, what we are going to do is 24 hours later we will come back. For a good head bolt or good head stud, the value that will be displayed here should not be below 1050 because, remember, everything is times 10 in lbs. here.

We are here 24 hours later; the current reading is 1429. It only gave up .35% of its original torque from yesterday. This is a really good head stud, as normal head studs and head bolts give up about 3 to 5% over a 24-hour time period. Our LS head studs didn’t even give up 1%.

Thank you for watching how EngineQuest tests all of our head studs and head bolts.