Main Stud Torque specs?

Hey guys,

My Halo girdle and Main studs came today. What should the main's be torqued too using studs?

 

Thanks Rob,

I see on TA's site where they say torque the mains to 110lbs..... Is there really if differance of 20lbs from Bolts to studs? That seems like a big differance.

Just to be on the safe side, can anyone else confirm the 90lbs spec for mains when using studs?

 

Just a quick question...

You are going to line hone that motor.. right?

It MUST be done..

Duplicate whatever specs of torque and type of lube that is used by the machinist when he line hones the block.

We use 110 ft lbs, with 30 wt oil here.

JW

 

I have to reline hone just from switching to studs? When the motor was built 5 years ago, it was line honed........ Maybe I should re plastic gauge the mains? I had no intent on tearning the guts out of the motor..............

 

Yup...

Studs and bolts "pull" the block differently..

The main bores on these things are so touchy, going from 100 ft/lbs to 110 WILL change the size of the main housings. Some times is see a small change, other times a much larger one.

Throwing the halo girdle into the mix compilcates things even more.

An example of how much these blocks move..

During a recent build of a block girdle motor, I was curious on how much the torque of those little 5/16 bolts, at only 25 ft/lbs could possibly have on the size and roundness of the main bores.. I mean come on.. the main caps/girdle are held in place with 1/2 dia bolts, at 100 + foot lbs..

So I did some fooling around on a couple different block girdle motors I had in the shop.. one had the water jackets fill to within an inch or so of the deck, the other had no water jacket filler.

I found that the "empty" block really made a difference in the overall size of the main housings, as well as the out of round.. I do believe it went .0005 out of round, with the vertical clearance being smaller without those little dinky bolts torqued.

The filled block did not move hardly at all, as the water jacket filler was doing exactly what we want it to.. strengthening the bottom end.. I do believe the bores went maybe .0001-.0002 (now that's tenths folks which is one thousanth (.001) split 10 times)

The moster size mains on these motors are very touchy, and are the source of more than one "chevy" shop screwing up a 455.

Personally, I think you would be better off running what you have now, and set those cool parts asided until your ready to freshen the motor up again.

JW

 

Hummmmm........

Man, I'm not sure if I would be better off resking the retorque, or letting the block go without stablizing it . Thanks for the input Jim, I'm just trying to see all my options, while getting it back together for Vegas. The motor is out of the car...... so something better get done to it besides droping the Compression via more grinding in the chambers and a thick head gastket :grin: