Head bolts

htr · Sep 28, 2014

K series head bolts. I see Rimmers and others offer uprated head bolts.
I been looking but haven't found details about these yet other than they are £20 extra.
In what way are they uprated?

Nodge68 · Sep 28, 2014

They are stronger. 9.8 instead of 8.8 iirc.
This gives a higher clamping load on the gasket at a lower pre-load.

htr · Sep 28, 2014

Nodge68 said:
They are stronger. 9.8 instead of 8.8 iirc.
This gives a higher clamping load on the gasket at a lower pre-load.

Thank you. Do they use a different tightening method?

Nodge68 · Sep 29, 2014

htr said:
Thank you. Do they use a different tightening method?

Hi Alan.
I've just checked this information rather than use my failing memory!
The standard bolt rating is 9.8 This requires a 20Nm initial pre-load followed by 180° rotation and a second 180° rotation to finish.
The stronger head bolts are rated at 10.9 These require the same 20Nm pre-load then a 180° initial rotation followed by a final 135° rotation.
I hope this helps.

Head bolts

htr

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Nodge68

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htr

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Nodge68

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