Re-torqueing Head Bolts(studs)

[BRENT FAY]

cmw.... I agree with with on your points about torqueing the heads .... I use a special socket that was made by Snap On that is about 4" long and 12 point for 1/2 in. nuts. (BTW they dont offer them any more) and use a slow steady pull, doesnt matter if click style or dial.

I read one of your other post about some lube you might manufactuer?........ but why do you think that everything has to be relubed? Are you saying that once something is torqued the lube is gone? Have you ever cleaned any nuts,washersand studs after taking an engine apart???? It is still there per say!!!! Didnt microscope the parts, but with the naked eye there was no galling and no problems.

Are you saying that your lube is gone after a certain PSI after torqueing? What good would that be? Thrashing between rounds, wait.....we must stop and clean every nut,washer and stud and relube! Or our head gasket are sure to fail!!??

I'm ignorant so help me. I'm sure you have a great product and have done more engines than I have and you have never had any failures. Thanks, Brent

[BRENT FAY]

Barry_R, Come to think about what my feeble mind remembers, I do think his name was Roger! Super nice person! Whats he into now? Brent

[68corvette]

What about bolts that go into water jacket?
i mean if you must use some kind of sealant isnt there a worry that water comes up if bolts are opened 1/4 and re torquet?

[cmw]

Brent, when you torque a fastener any type of lube can squeeze out and you are also burnishing the treads of the fasteners,it is a good practice to relube. I have tested fasteners after the rods were cleaned installed and there was not enough lube on them. The clamp load diminishes after the second time you use any torque lube. It does not drop alot but it does drop. Just think if the shop that resizes your rods uses another lube than what you use what could happen. All I am trying to get accross is to be as correct as you can to be consistent. I have my lubes on Cup, Busch,NHRA,IHRA engine builders. You need to lube the fastener every time to take it apart. I have broke and seized nuts and bolts together, this is how you learn and correct the problem.

[Silverback]

FWIW, I don’t see the point of backing off one bolt at a time and torquing it (will not tension the head in the same way as if they were torqued in the correct order) or just checking torque on the bolts (unless something backed off or moved you’ll be fighting more break away torque then anything else).

For heads (and I’ve done this on intake manifolds also but they are nowhere near as critical, but if the manifold is already installed you really need to loosen them to get even torque on the heads), I almost always do the cold retorque thing, I back them all off about ¼ turn and then torque them all again at least a few hours later, usually overnight or so, and then with my own stuff or stuff that I see after it’s been run I will do the same deal a few heat cycles in or any time I have a reason to disassemble it enough that they are exposed. I do tend to give them all a squirt of whatever I was using to lube them out of a pump oiler type thing after I loosen them and before I retorque them but I doubt that it really does a difference unless we’re talking about studs/nuts/washers.

As far as head bolts that go into water jackets… I don’t know what to tell you. I’ve never been particularly happy with anything that I’ve used on the threads because even though I can’t remember the last time I actually had a leak if ever on anything that I did, it does seem like some disproportionate amount of them that I take apart have some signs of weeping around the bolt heads/washers on top. Anything that hardens like RTV should leak if you retorque it, it seems that everyplace that I’ve ever used any Teflon pipe thread dope type stuff I’ve had leaks so I’ve never actually tried the “right” stuff on those threads (that and supposedly the ARP stuff isn’t sensor safe). I’m debating trying one of the aircraft grade, 3 series permatexes or the 300 series stuff or some hylomar, but since I don’t know anyone that has tried them so that makes me nervous. Usually I try to use a stud in that case, so you can seal the bottom threads and do whatever on the top threads, but that is not always an option (a lot of my time is spent with SBC’s in F-bodies which don’t have room to remove the heads with studs installed, there’s no chance in hell on the 4th gens where the bottom half of the engine is under the cowl), and to be honest with you I tend to play those by ear… I do what feels the most right at the time I’m doing them.

[cmw]

When you get your rods they have been lubed to put them together. I check bolt length before I take them apart. Now what if the bolts were not installed with the stretch that you use. All I am trying to show you that there could be problems from the get go. When you get rods resized did you spec the torque lube to be used on YOUR RODS. Did they torque them properly. (bolt stretch length) And when you get them do you clean the rods or just (I hope not) just install them. Are you checking if there is enough lube on the bolts when you are checking Clearances and doing your pre-assembly??? This also goes with any load point fasteners in your engine. If you angle mill your heads did you respot face all the bolt holes?
Hopefully paying attention to details increases engine life.

[awesomebill]

When you get your rods they have been lubed to put them together. I check bolt length before I take them apart. Now what if the bolts were not installed with the stretch that you use. All I am trying to show you that there could be problems from the get go. When you get rods resized did you spec the torque lube to be used on YOUR RODS. Did they torque them properly. (bolt stretch length) And when you get them do you clean the rods or just (I hope not) just install them. Are you checking if there is enough lube on the bolts when you are checking Clearances and doing your pre-assembly??? This also goes with any load point fasteners in your engine. If you angle mill your heads did you respot face all the bolt holes?
Hopefully paying attention to details increases engine life.

Even our shop torques all bolts down and then goes back over to make sure all were hit. We then take one at a time from the center out, back it off and then pull it right to 70. This allows the bolt to come to stretch without stopping at 50-60-and then 70. The sheer factor when this is done stops and starts and may not be evenly torqued tight. We then back one at a time off and bring it right to 70 in 1 sweep, sometimes it will chatter so we take the bolt out and relube and boom, you got a good smooth pull.

You will have proper stretch along with a nicely burnished area under and over the washer area along with the 7/16 block threaded area. We have done this for years and have never had a bolt need to be retorqued even after dyno pulls.

Ofcourse, people have also done it 50-60-70 and retorque after warm up and have not had a problem either. Who's right? I would think that 1 pull to 70 after total head clamp was achieved would be more accurate.

We also use the same lube the honing man does when he machines the block. Both have the same stuff and both have the same torque wrench. I think this would promote better cylinder wall prep for ring sealing being we can reproduce what the cylinder wall sees every time.

Trying to keep the 2 procedures and not get into super expensive trick stuff works very well for us.

As we all know, most head gaskets come pre rolled. They squeeze these things more evenly than we ever could. So retorque should not be needed.

Now for copper oring and reciever groove, you will need to go over a few times and after warm up before yeilding proper clampingload. JMO