Re-torquing cylinder heads

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Re-torquing cylinder heads

Postby MalcW » Mon Jul 08, 2019 8:14 am

Hi

When re-torquing a cylinder head, should you just apply the torque wrench until it clicks, or back the nuts off slightly and then re-torque. The first couple of times (this is with a composite gasket) it's not necessary, in fact it's quite amazing how much the gasket has settled. But when checking them after a few hundred miles and a few re-torques I sometimes feel like I might be overtightening them slightly before the torque wrench gives.

I've done it both ways, but I wondered which is correct.

Malc

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Re: Re-torquing cylinder heads

Postby Mick D » Mon Jul 08, 2019 8:32 am

Hi

Get as much information from the process as you can.

Set the torque wrench to the required torque and torque the fasteners, (in the correct sequence), note if any move indicating the gasket has settled.

Now back off the fasteners about 1/4 of a turn and re-torque, again following the sequence for both loosening and tightening - this negates any 'sticktion' in the fasteners and applies the correct torque.

Regards Mick

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Re: Re-torquing cylinder heads

Postby MalcW » Mon Jul 08, 2019 9:47 am

Thanks Mick

I've done 400 - 500 miles since changing the gaskets, and everything seems fine, but I want to check them again, just to be sure.

Malc

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Re: Re-torquing cylinder heads

Postby Ozmadman » Tue Jul 09, 2019 10:50 am

Mick D wrote:Hi

Get as much information from the process as you can.

Set the torque wrench to the required torque and torque the fasteners, (in the correct sequence), note if any move indicating the gasket has settled.

Now back off the fasteners about 1/4 of a turn and re-torque, again following the sequence for both loosening and tightening - this negates any 'sticktion' in the fasteners and applies the correct torque.

Regards Mick

+1
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed

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