[pavel]

General question that probably applies to any aluminum block.

When you torque head bolts there's a large amount of force on the threads deep in the block. Are those threads just tapped into the aluminum material, or are there steel inserts cast in down there which can withstand the forces much more easily? Perhaps there are glued-in "helicoils"... does anyone know?

Cheers, Pavel.

 

[p76rangie]

General question that probably applies to any aluminum block.

When you torque head bolts there's a large amount of force on the threads deep in the block. Are those threads just tapped into the aluminum material, or are there steel inserts cast in down there which can withstand the forces much more easily? Perhaps there are glued-in "helicoils"... does anyone know?

Cheers, Pavel.

Just tapped into the aluminium. Nothing special there.

 

[pavel]

I wonder how many threads the steel head-bolts are holding onto down in the block... Generally, with steel, you need about as many threads as make up the width of the bolt, perhaps a few more. But with aluminum, you surely need double or treble that? I'm amazed there isn't a steel insert down there.