The reality of the torque sequence

[hombres ruin]

I just installed new head gaskets with my aluminum heads I need to know once I have the final torque and run the engine to op temp then cool I need to re torque but do I retorque going up in foot lbs like 35,45,55 or do i retorque on the highest ft lbs e.g ..55

[ford3]

all ways torque any head in the torque pattern and go up in steps

[Karl Wolf]

Use steps for initial tightening,Not for retorque... When I retorque, I start each bolt (singely) by releasing the tension (loosening). I find that with this the nut moves farther than just retorque from the set position...

I took a silver pencil, made lines to check my theory. One time.
Karl

[cuzncletus]

I was at a friend's house watching an old mechanic assemble a Ford 6. It was a government job; one man working a five supervisors. I did offer one supervisory piece of advice as I watched him torque lower end bolts. He pulled the mains front to back. Then he pulled the rods. All were pulled one time each to max torque using the old bar-type torque wrench. No torque sequence, which I'm not sure is that important on mains but I always pull from the middle out when I don't know. But no oil on the threads, no pulling in steps, no turning for resistance after each rod was tightened. It makes me wonder how long the engine will last and if I ought to stick my nose in to try to help my buddy. These two guy are old friends but I hate to see someone face the effort and expense of a rebuild because their friend was too lazy to torque bolts in increments.

P.S. I didn't watch the head go on.

[hombres ruin]

Some differing views on this. Should I back the bolts off before each warm up/cool down retorque?.

[V8COOPMAN]

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Do NOT loosen! Just re-snug back to final figure, following the circular sequence. DD

[ford3]

my mistake , read the post wrong, the guys are right,when retorquing torque to max specs, do not loosen the bolt or nut, sorry, im old lol, if you really want true torque, take a bottoming tap with grease applied in the flutes to catch the particals that will be loosend up, run to bottom to clean threads, same with the studs, run a dye over the threads, then lightly oil bolts or nuts and procede to torque, if you dont do that your not getting a true torque reading because of the added resistence of dirty threads, check torque charts, two different readings for wet and dry totque

[Ol' Ron]

The Flathead is very forgiving, I've put engines together without a torque wrench. Couldn't afford one.

[flatjack9]

I never run a tap in the threads for head bolts. Ford used a special tap that provided a tight fit. I use an old head bolt and cut slots along the length of the thread and use them to clean out bolt holes. I wire brush the bolt or stud threads. As far as retorqueing, I can see no problem with backing off a slight amount and then drawing up to full torque. I think you will get a truer reading. And I wouldn't worry about the sequence on retorqueing, start on one end and work to the other.

[hombres ruin]

Thanks guys. I cleaned the bolts holes of particles using a long brush and an air gun which got any reside out no problems and never ruin the threads . I will torque at 55 ft lbs per aluminum head.

[Mart]

I ain't no expert, BUT didn't Ol Ron say 45 lbs is plenty for an Aluminium head? You talkin bolts or studs and nuts?

Mart.

[Henry/Kokomo]

Good point, Mart. The studs, with the finer threads, will exert more clamping force per ft/lb applied than will the coarser threaded bolts.

[flatjack9]

Yes, 45 lb is quite sufficient. No more than 50.

[BillM]

On re-torquing: A method a mechanic friend of mine used was to check each bolt with a beam and pointer type wrench; slowly approaching the final toque value to see if the bolt would move before reaching the final value. If it did then he would back off the bolt and re-torque. Just one of several ways to skin this cat.

[4t8v8]

Edelbrock's instructions are: Tighten in the order the engine manufacturer recommends. Tighten in 3 increments - 20 ft#, 40 ft # then 50. Warm the engine to operating temp twice and re-torque both times. Did it the way they recommended but stopped at 45#. Figured that was plenty. Back when I was a young feller I didn't have money for a torque wrench. Built a bunch of them and never had a problem.

[Ol' Ron]

I'm supprised how many times this comes up. Torque to #45 in 3 equal steps. Then re-torque through 3 heat cycles. Start fron the middle and work out. Over torquing can cause deck warping and broken Bolts/studs. Now how many of you have broken a stud or bolt when torquing to 55-65 lbs.??

[Lawrie]

We run our blown engine on 45ftlbs ,12psi boost no drama.
Lawrie

[40grit]

Originally Posted by Ol' Ron

I'm supprised how many times this comes up. Torque to #45 in 3 equal steps. Then re-torque through 3 heat cycles. Start fron the middle and work out. Over torquing can cause deck warping and broken Bolts/studs. Now how many of you have broken a stud or bolt when torquing to 55-65 lbs.??

Ron is correct. Torque through 3 heat cycles. You will pull more every time. Especially if you are torqueing aluminum heads with composit head gaskets. I went back a month or so later and still pulled more on a few head bolts.

John L

[dumb person]

Originally Posted by Ol' Ron

I'm supprised how many times this comes up. Torque to #45 in 3 equal steps. Then re-torque through 3 heat cycles. Start fron the middle and work out. Over torquing can cause deck warping and broken Bolts/studs. Now how many of you have broken a stud or bolt when torquing to 55-65 lbs.??

i stripped helicoils torquing to 55...

[joel]

Ah yes , the old calibrated fingers. LOL. Ron, your comments brighten my day