1135 cylinder head torque

[1135]

I rebuilt my 1135 which is now due its first service. I used molybdenum disulfide  under the nuts as I have done with other engines. In the genuine Suzuki manual it says undo each cylinder head nut and then re-tighten, what is the point of this normally you just re-torque not undo first.

Any body got any ideas? just trying to understand why!

[gs7_11]

I'd assume it's something to do with breaking a corrosive bond or stiction which might stop you getting an accurate torque.

Torque figures are for dry threads normally, so that might be why it's an issue.

If you grease the threads all bets are off anyway.

I've come across this method on my BM before, and it makes a difference. You can measure tappet clearances before and after and they change, being a pushrod engine, so it's doing something!

[1135]

On 3/30/2019 at 11:06 AM, gs7_11 said:

I'd assume it's something to do with breaking a corrosive bond or stiction which might stop you getting an accurate torque.

Torque figures are for dry threads normally, so that might be why it's an issue.

If you grease the threads all bets are off anyway.

I've come across this method on my BM before, and it makes a difference. You can measure tappet clearances before and after and they change, being a pushrod engine, so it's doing something!

Hi, thank you for that, I don't lubricate the threads just surface between  nuts and washers, I will do it by the genuine w/shop manual

[Reinhoud]

On 3/27/2019 at 6:30 AM, 1135 said:

I rebuilt my 1135 which is now due its first service. I used molybdenum disulfide  under the nuts as I have done with other engines. In the genuine Suzuki manual it says undo each cylinder head nut and then re-tighten, what is the point of this normally you just re-torque not undo first.

Any body got any ideas? just trying to understand why!

Thread works on friction, if you use a grease or whatever, you reduce the friction, when you reduce the friction, and then you torque it at the mentioned setting, you turn the nut/bolt a lot further then it's supposed to be, which can lead to stripped thread, and this is something you have to keep in mind, especially when working with aluminium, also the nut/bolt can come loose. 

The studs and the nuts may be steel, but the crank case isn't.

 

A lot of people put all kinds of stuff on thread, just clean it and degrease it, and you won't have any problems.

[Reinhoud]

On 4/1/2019 at 6:42 AM, 1135 said:

Hi, thank you for that, I don't lubricate the threads just surface between  nuts and washers, I will do it by the genuine w/shop manual

If you work with torque, don't! If you work with angles, you can, but I wouldn't, because it can come loose because of reduced friction. Just clean it.

Edited April 10, 2019 by Reinhoud