retorqunig cylinder heads after 1000 miles NECESSARY?

[fredmeister]

I wanted to know if it were really necessary to retorque the cylinder head studs after running the engine for 1000 miles or so?

Considering the magnitude of what it takes to get to the cylinder head nuts with the engine in the car to retorque them, is this something that can be skipped or am I making a terrible mistake?

I have a '79 3.4 liter turbo and am using 98mm Nickies and ARP studs. I am doing a top end rebuild (detonated a piston or 2) and noticed some witness marks on my heads and top surfaces of the liners indicating a little movement after 4000 miles of running.

I did not retorque these after the original engine break in, but dont know if the detonation is to blame for the witness marks or by me skipping the retorque process.

Also, is it possible to get to the cylinder head nuts, say with a partial engine drop, so that I dont go thru an entire engine drop just to retorque the nuts?

Thanks,
Fred

[afterburn 549]

Most will say no.........

[porterdog]

Originally Posted by fredmeister

...am using 98mm Nickies and ARP studs.

I imagine Charles at LN has some insight; have you contacted them?

[BURN-BROS]

I would verify the torque when it's time to adjust valves.

[Steve@Rennsport]

Originally Posted by fredmeister

I wanted to know if it were really necessary to retorque the cylinder head studs after running the engine for 1000 miles or so?

Considering the magnitude of what it takes to get to the cylinder head nuts with the engine in the car to retorque them, is this something that can be skipped or am I making a terrible mistake?

I have a '79 3.4 liter turbo and am using 98mm Nickies and ARP studs. I am doing a top end rebuild (detonated a piston or 2) and noticed some witness marks on my heads and top surfaces of the liners indicating a little movement after 4000 miles of running.

I did not retorque these after the original engine break in, but dont know if the detonation is to blame for the witness marks or by me skipping the retorque process.

Also, is it possible to get to the cylinder head nuts, say with a partial engine drop, so that I dont go thru an entire engine drop just to retorque the nuts?

Thanks,
Fred

Hi Fred,

JMHO,....

You need to stay on top of head torque using ARP studs in a Turbo motor. While they are plenty strong, I've found that the head nuts do not maintain torque settings and loosen up due to differential expansion rates between the studs & cylinders.

We do not use ARP head studs in any engine for this reason and instead, prefer the factory 993TT ones as used in the RSR & GT-2 race engines.