How many times does a guy have to retorque the head studs on an oringed head to get a proper seal?? I had the block and the head CNCed perfectly flat. Had the head Oringed and buttoned it up with head studs torqued to 125#. Fired it up ran a few miles and retorqued. About 200 miles later Im leaking coolant. Retorque and no more leak. About 500 miles later Im leaking coolant. Retorque no more leak. I put on about 4000 miles with no problem. Boost has been under 40 at all times. Last week I pull a heavy load for the first time and really worked the engine. Higher EGTS and Higher boost levels. Nothing outrageous and now Im leaking coolant again. Time for another retorque I guess. How many times does it take to get a good seal??

 

Whose studs did you get that are torqued to 125ft/lbs?

Also, not all torque wrenches are accurate. If the bolt is over torqued past it's point of elasticity, it will continue to stretch and stretch.

Do the re-torques feel spongy? Are you loosening them (one at a time), and retorquing? Have you checked your torque wrench?

Any idea how much protrusion was left in the o-ring wire? If too much, the head can't seat down far enough.

It shouldn't take but the intitial torque, warm the engine to operating temp, and cool to about 140 deg, then retorque. After about 400 miles, retorque one more time, and that should be good....

 

Haisley studs. Could be the wrench. Not sure what kind it is. Retorques feel good, not spongy at all. Torque procedure is like you describe. Loosen, retorque, loosen, retorque one at a time. How can I check the wrech? Not sure on the oring protrusion but I will check.

One question, is it neccessary to relube the nuts and studs to do the retorque?? I have been and it takes alot of extra to do it. Seems like it definately wouldnt hurt so I have been lubing them each time.

Thanks,
Chad

 

[QUOTE=One question, is it neccessary to relube the nuts and studs to do the retorque?? I have been and it takes alot of extra to do it. Seems like it definately wouldnt hurt so I have been lubing them each time.
Thanks,
Chad[/QUOTE]
Lubed with what? 125 ft-lbs with different lubes gives different tension. I did my Haisley 12mm retorque to 125 with no additional lube. Has held for 20 months. Checked last month without loosening and still ok.

RJ

 

How to check the torque wrench...

I'll tell ya what I do, but your gonna laugh...



Aren't ya!.....


OK, if you PROMISE....



Put the square drive shaft in the work bench and tighten.
Measure 12" (1 foot) from the center of the drive shaft up the handle.
Wrap and tighten wire at this location.
Suspend a 5 gallon bucket from the wire.
Weight (with a known, reasonably good scale) your tool box, or what ever. I have dumb bells and flat plates for weight lifting that stack into the bucket.
Set the torque wrench for the weight of the stuff you weighed (hopefully 125 lbs).
Place the mass into the bucket while holding the handle up.
Gently release the handle. Did the wrench click (if break away type), did the needle point at the correct weight (if torsion type)....

Some torque wrenches can be adjusted, some can not. Break aways usually can.

For your own information, you chould check the wrench over most of it's rating. If you know how far it's off for a reasonably small range of weights, just compensate for it.

 

HEY!

You PROMISED not to laugh!!!

 

Blue, why didnt I think of that. Thats good. Maybe Ill have my 125# daughter do some pullups on the torque wrench. If it it clicks......
Thanks for the help.

I have always taken the nuts off, lube the nut, washer, and stud with ARP Moly lube and then retorque. If I dont have to relube that would save some time. I''ll try it this time.

 

I always pull the nut and washer, then lube the threads, washer and nut again. This ensures that the torque is being applied to the stud and not the twisting moment.

Doug

 

Doug has the strongest o-ring system I have ever seen. Just plain ol, run of the mill stainless o-rings and a marine gasket using the ARP studs TQ'd to normal values. It has held back 832 HP with nitrous for a year now!

Don~