Head Bolts Vs. Head Studs
05-02-2009, 01:34 PM
#1
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Head Bolts Vs. Head Studs I have decided to pull my heads off when i am doing my cam swap to port them out. I am going with aftermarket fastners so i dont have to deal with the torque to yield stuff. I am putting a blower on the motor and plan to run around 10 psi of boost. I dont know weather i shoudl run studs or bolts
Which do you guys prefer, is there any quirks with either that i should be aware of?
Thanks
Which do you guys prefer, is there any quirks with either that i should be aware of?
Thanks
05-02-2009, 04:25 PM
#5
studs for sure.
holds better, looks cooler, cleaner to maintain, but most important when you pull the heads off you dont have to deal and clean up as much deep in the holes when the coolant pours down. Assuming you might have to take heads off at least once more.
they arent that much more for all the added benefits
holds better, looks cooler, cleaner to maintain, but most important when you pull the heads off you dont have to deal and clean up as much deep in the holes when the coolant pours down. Assuming you might have to take heads off at least once more.
they arent that much more for all the added benefits
05-02-2009, 06:53 PM
#8
One of the primary advantages of studs is you have full thread engagement in the aluminum block when you start applying the torque to the nut (loading the threads). Secondly, since the stud is threaded on the head side to match the block, the nut side can have a different thread for better load distribution. My vote would be for studs.
Should you re-torque? That's up to you but I did after two heat cycles and found that there was some change. To do this, back off 1/8 turn and then re-tighten to the correct torque one stud at a time in order.
Should you re-torque? That's up to you but I did after two heat cycles and found that there was some change. To do this, back off 1/8 turn and then re-tighten to the correct torque one stud at a time in order.
05-03-2009, 06:47 AM
#12
Just make sure you don't drag the head across the studs when installing. If this is an issue, install the head on the upper studs and dowels, then install the studs afterwards if they will fit using this method. I had to do this on a few studs due to interference with the header flange.
05-03-2009, 09:09 AM
#13
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Studs wont stretch with the added cyl pressure and bolts will. Using studs will not let your heads lift and coolant go everywhere. Those are just some obvious advantages.
05-03-2009, 10:26 AM
#14
On my engine i have about 1" clearance between the stud and the body. you can install the head but just be careful. The hardest part to me is putting on MLS head gaskets, the layers will hang on the stud threads and intends to hang up.Just take your time and every thing will fit just fine.Im just glad the we have aluminum heads, Cast iron heads would be very difficult to in stall on a f-body with studs, trying to hold the head and not scuffing the heads ageist the stud.
05-04-2009, 04:52 PM
#15
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well im going to go with the studs then, the install is not a problem for me the engine is in a old chevy truck and i am going to have the motor out when i pull the heads
05-04-2009, 05:17 PM
#16
Bolts will twist when you torque them down, this increases the load placed on the material as well as the stretching from being torqued. Which inadvertly reduces clamping force and under higher cylinder pressures will fail due to a twist and stretch force acting upon the shaft of the bolt. Studs do not experience the twist force of the bolts, so they only see the stretch factor. This results in more consistent torque reading and better clamping force for high cylinder pressures.
