Temperature during head torque

[hogrdr]

I am in the process of torqueing my heads. My garage is 45°. Will that affect my torque. Using a cometic gasket.

[No Cents]

 your good...I've torqued heads out in the barn way below freezing temps.
Just make sure you put a little dab of oil on the head bolt threads and on the shoulder of the bolt.

[kd]

    ....  emphasis on "little" dab   

[hogrdr]

Thanks that's good to know

[Phu Cat]

put a little dab of oil on the head bolt threads

Interesting.  Won't that throw off torque reading?

PC

[kd]

put a little dab of oil on the head bolt threads

Interesting.  Won't that throw off torque reading?

PC

   ....  emphasis on "little" dab   

A trace drop on the start of the "clean" stud thread and a light smudge on the face of the nut prevents galling and drag that WILL effect the torque applied. It is not meant to lube but more to prevent drag that robs the torque applied and gives a lower clamping or stretch in the fasteners.

[1FSTRK]

Normally when a manual specifies lube on threads and clamp surfaces like the HD factory manuals do, the torque specs given have been set with the specified lube in place.

[Norton Commando]

Normally when a manual specifies lube on threads and clamp surfaces like the HD factory manuals do, the torque specs given have been set with the specified lube in place.

Exactly 

Jason

[rbabos]

Normally when a manual specifies lube on threads and clamp surfaces like the HD factory manuals do, the torque specs given have been set with the specified lube in place.

True but the manual only gives initial torque then 90* or whatever. I've always been one to increment the torque to full value of 40-42 lbs but after dealing with an older bike with rusted stud threads and nuts, I will use the degree method on all from now on for any stretch studs. Way too much error factor with torquing in increments with uneven friction between threads or face contacts and made worse with stopping the rotation for the next level of torque. Lube starts to burn off and this again is uneven between them. This has been proven over and over again. One of those old school methods that just keep hanging on but no way accurate or the best method. Let's face it x amount of rotation on a thread creates x amount of repeatable clamping, each time.
Ron

[1FSTRK]

Normally when a manual specifies lube on threads and clamp surfaces like the HD factory manuals do, the torque specs given have been set with the specified lube in place.

True but the manual only gives initial torque then 90* or whatever. I've always been one to increment the torque to full value of 40-42 lbs but after dealing with an older bike with rusted stud threads and nuts, I will use the degree method on all from now on for any stretch studs. Way too much error factor with torquing in increments with uneven friction between threads or face contacts and made worse with stopping the rotation for the next level of torque. Lube starts to burn off and this again is uneven between them. This has been proven over and over again. One of those old school methods that just keep hanging on but no way accurate or the best method. Let's face it x amount of rotation on a thread creates x amount of repeatable clamping, each time.
Ron

Agreed
The factory head sequence uses all three, lube, very low torque values (which are also effected by lube) and the degrees of final rotation. We found long ago that converting to inch/lbs when ever possible will keep the lower torque numbers more accurate before moving to the degree step.

[Norton Commando]

Normally when a manual specifies lube on threads and clamp surfaces like the HD factory manuals do, the torque specs given have been set with the specified lube in place.

True but the manual only gives initial torque then 90* or whatever. I've always been one to increment the torque to full value of 40-42 lbs but after dealing with an older bike with rusted stud threads and nuts, I will use the degree method on all from now on for any stretch studs. Way too much error factor with torquing in increments with uneven friction between threads or face contacts and made worse with stopping the rotation for the next level of torque. Lube starts to burn off and this again is uneven between them. This has been proven over and over again. One of those old school methods that just keep hanging on but no way accurate or the best method. Let's face it x amount of rotation on a thread creates x amount of repeatable clamping, each time.
Ron

Using a torque value to pre-load a fastener is inherently flawed. Small variations in friction have a huge affect on preload; therefore torquing fasteners has a pre-load error of +/- 25%.

The turn-of-nut method is superior but not without flaws, too. The tricky part is understanding when to start measuring rotation. That's why turn-of-nut uses a nominal toque value initially to ensure all slack has been removed followed by turning X-degrees. Also, stud wind-up is difficult to account for accurately.

Nevertheless the turn-of-nut method is superior to torque as its error is +/- 15% compared to +/- 25% for the torque method.

Best,

Jason

[Phu Cat]

 stud wind-up is difficult to account for accurately.

Yer one-up on me here.  What's 'stud wind-up' mean?  Never heard this phrase before.a

PC

(In my little league days I thought I was quite the stud because I was a pitcher altho my wind-up left a lot to be desir............Never mind.)

[Tail Ridr]

 

[Norton Commando]

stud wind-up is difficult to account for accurately.

Yer one-up on me here.  What's 'stud wind-up' mean?  Never heard this phrase before.a

PC

(In my little league days I thought I was quite the stud because I was a pitcher altho my wind-up left a lot to be desir............Never mind.)

Ha, that's a good one!

Stud wind-up occurs when you have long studs, such as the case with the Japanese in-line-fours and even the longish studs for securing head and cylinder assemblies on HDs. What can happen is that the stud may actually twist slightly when rotating the nut. For example, if during nut rotation the stud twists two degrees, that's two degrees of rotation that is not accomplishing preload.  So for a 45-degree nut rotation a two-degree stud twist would result in a preload error of nearly 5%.

Best,

Jason

[rbabos]

stud wind-up is difficult to account for accurately.

Yer one-up on me here.  What's 'stud wind-up' mean?  Never heard this phrase before.a

PC

(In my little league days I thought I was quite the stud because I was a pitcher altho my wind-up left a lot to be desir............Never mind.)

Ha, that's a good one!

Stud wind-up occurs when you have long studs, such as the case with the Japanese in-line-fours and even the longish studs for securing head and cylinder assemblies on HDs. What can happen is that the stud may actually twist slightly when rotating the nut. For example, if during nut rotation the stud twists two degrees, that's two degrees of rotation that is not accomplishing preload.  So for a 45-degree nut rotation a two-degree stud twist would result in a preload error of nearly 5%.

Best,

Jason

I've seen this happen even with the torque method on my softail at the time. I used cam break in lube on the nut faces and plain old oil on the threads. At any point the friction is less under the nut then the thread area, you can see the nut rebound slightly from stud torsional effect. If the friction is high at the nut face, head interface, you won't notice it but the stud will end up with a slight torsional load when torquing is done. It's there, you just won't see the effect. Most never notice any of this, nor would have I , had it not been for the super lube on the nut faces. It was an easy 5* rebound in rotation.  Minimum torque and rotational degrees is still the best method to eliminate as much clamping variances between studs for overall errors but you are correct, the torsional stud wind up still exists but if all of them do it about the same +/- a couple of degrees, it's not earth shattering in overall error.
Ron

[Hillside Motorcycle]

Normally when a manual specifies lube on threads and clamp surfaces like the HD factory manuals do, the torque specs given have been set with the specified lube in place.

True but the manual only gives initial torque then 90* or whatever. I've always been one to increment the torque to full value of 40-42 lbs but after dealing with an older bike with rusted stud threads and nuts, I will use the degree method on all from now on for any stretch studs. Way too much error factor with torquing in increments with uneven friction between threads or face contacts and made worse with stopping the rotation for the next level of torque. Lube starts to burn off and this again is uneven between them. This has been proven over and over again. One of those old school methods that just keep hanging on but no way accurate or the best method. Let's face it x amount of rotation on a thread creates x amount of repeatable clamping, each time.
Ron

Agreed
The factory head sequence uses all three, lube, very low torque values (which are also effected by lube) and the degrees of final rotation. We found long ago that converting to inch/lbs when ever possible will keep the lower torque numbers more accurate before moving to the degree step.

Who is "we"?