How You Torque Head Bolts

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Cray2751
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How You Torque Head Bolts

#1

Post by Cray2751 » Fri Nov 17, 2017 7:47 pm

Ok I know.... I’m not asking about the tools you use or the gasket material but how you torque your head bolts in the frame. No manual really goes over this. Here is what I have been doing. On a cold bike loosen the top motor mount grab my torque wrench and check base nuts at 35ft pounds then head bolts to 65 ft pounds. It hit me last night that I maybe should be rolling the motor over where the pushrods on the cylinder I am torquing are on the base. I am using hydraulic units. Am I over thinking or just have been doing it all wrong this entire time



Doc37W
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Re: How You Torque Head Bolts

#2

Post by Doc37W » Fri Nov 17, 2017 8:32 pm

Over thinking it. Doc

Bigincher
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Re: How You Torque Head Bolts

#3

Post by Bigincher » Sat Nov 18, 2017 5:21 am

Doc, is loosening the top motor mount necessary? Seems like snugging a few foot/pounds would have little effect on the top mount. I could see it if you were drawing the heads down a measurable distance, even a few thousandths. But will 5-10 ft/lbs, let's say, draw the heads down any measurable amount really?
Standard procedure may be to loosen the top mount bolt- and it seems logical- but I've always wondered about the necessity to do so. What are your thoughts?

Doc37W
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Re: How You Torque Head Bolts

#4

Post by Doc37W » Sat Nov 18, 2017 4:51 pm

Tom, I've done it both ways, Loosening the top motor mount first to torque the heads and/or just going after the head bolts & base nuts. If you're just checking the torque with a "clicker style" torque wrench, I don't bother, as you're not trying to cinch them down any significent distance. However, If you find one or more that are loose, I would loosen the top mount as you could be shifting the top end parts. One thing to check is the spacing of the mount to the frame tab when installing the engine the first time or replacing the mount. I try to get the spacers & shims to just slip in between snugly with the nuts & washers on the heads tight. I've replaced many broken top mounts because it was pulled into the frame on account of it was lacking the proper spacers/shims. Doc

Bigincher
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Re: How You Torque Head Bolts

#5

Post by Bigincher » Sat Nov 18, 2017 5:51 pm

Doc37W wrote:
Sat Nov 18, 2017 4:51 pm
... One thing to check is the spacing of the mount to the frame tab when installing the engine the first time or replacing the mount. I try to get the spacers & shims to just slip in between snugly with the nuts & washers on the heads tight. ...
Yes, that's a given. Very important step.

Cray2751
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Re: How You Torque Head Bolts

#6

Post by Cray2751 » Mon Nov 20, 2017 3:54 am

Doc37W wrote:
Fri Nov 17, 2017 8:32 pm
Over thinking it. Doc
Usually the story of my life Doc. Thanks for the input.

Tunglegubbin
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Re: How You Torque Head Bolts

#7

Post by Tunglegubbin » Tue Nov 21, 2017 9:36 am

“If you're just checking the torque with a "clicker style" torque wrench, I don't bother,”

I might have misinterpreted your message but if you’re re-torquing you should loosen the bolt first.

Cray2751
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Re: How You Torque Head Bolts

#8

Post by Cray2751 » Fri Nov 24, 2017 4:38 am

Tunglegubbin wrote:
Tue Nov 21, 2017 9:36 am
“If you're just checking the torque with a "clicker style" torque wrench, I don't bother,”

I might have misinterpreted your message but if you’re re-torquing you should loosen the bolt first.
Checking the torque at 500, 1000, 2500 intervals. Just the PM headbolt checks

Doc37W
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Re: How You Torque Head Bolts

#9

Post by Doc37W » Fri Nov 24, 2017 10:05 pm

I would never loosen a head bolt when just checking the torque of it. However, if I found 1 or more bolts undertorqued or loose, THEN, I would, in order to retorque it and its' companions evenly. But first I would try to figure out why it was loose. (broken bolt, stripped threads, forgot to tighten, etc.) That's why a "clicker" type torque wrench is used. It breaks or "clicks" when the PRESET torque is reached. The trick is to pull slowly on it untill you get to the preset, not just yank on it, as you can get it to click at a lower torque. Doc

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