: jakes studs



sassanach
07-14-10, 04:06 PM
as a matter of idle curisoity,are the head studs jake supplies torqued the same as head bolts or tighter/looser ? is there any advantage to being tighter etc.(ps mods, if this is sensitive info feel free to delete as appropriate)

Submariner409
07-14-10, 05:14 PM
Head bolts or studs are torqued to either a specific ft/lb setting OR to a set angular rotation figure after initial preload torque.

The idea is to apply an even, high clamping force across the entire cylinder head gasket surface in order to (hopefully) sandwich two huge pieces of metal into one gasket-sealed block. (romantic, but you get the idea).

Anyway, the torque or load on the bolts is engineer-deduced to apply a certain amount of bolt stretch in order to achieve the clamp pressure, so the final torque is dependent on what you're doing with what size bolts.

Usually, applying too much torque for a given assembly breaks things - like pulled/broken bolts and cracked heads.

Jakes nuts :rolleyes: come with specific torque settings in the directions.

97EldoCoupe
07-14-10, 05:33 PM
Clamping pressure on the head gasket is about the same amount as the factory head bolts. Actually just a touch more.

Much more even clamping force though. Torque specs on the nuts are 75 ft. lbs. done in three passes to promote even clamping across the head. The new rolled thread studs will handle 110 ft. lbs. without any damage; but I advise DO NOT torque to this amount. The studs have a very smooth, fine thread on top so 75 ft. lbs. on these fine threads is actually producing a lot of clamping pressure.

Coarse thread in the block, fully engaged in the aluminum before any torque is applied; fine thread on top for even and accurate torquing. This is the combination required for a successful head gasket job on an aluminum block engine.

This is a valid question and you have all the rights to ask this.

I was on the phone today with Engine Builders Magazine- (www.enginebuildermag.com) Northstar Performance is going to be featured in the December issue; particularly with the thread repair method known as the SureGrip Stud Kit!