Head Torque

PostPost by: steveww » Mon Jul 09, 2007 8:40 pm

How many miles should I put on the car after refitting the head before rechecking the torque of the head bolts?
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PostPost by: gjz30075 » Tue Jul 10, 2007 11:49 am

Steve, one heat cycle should do it, although it depends on the type of material the gasket is made of. I've used composite type material gaskets.
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PostPost by: garyeanderson » Tue Jul 10, 2007 12:13 pm

I would follow the head gasket manufactures recomendation. I know Ajusa has it on the packaging instructions.
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PostPost by: types26/36 » Thu Jul 12, 2007 9:20 am

steveww wrote:How many miles should I put on the car after refitting the head before rechecking the torque of the head bolts?


The workshop manual says to tighten the head bolts at the Initial Service @ (500 miles) and there after @ the C service every 6000 miles.
This is of course with the standard Lotus gasket but if you are useing an other type of gasket as others have said follow the manufacture's recommendations.
For my part I run the engine hot (until the electric fan cuts in) two or three times then leave it overnight to get stone cold and retighten, after about 500 miles then retighten with engine cold.
Brian
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PostPost by: paros » Sat Jul 14, 2007 6:38 pm

I agree with all that has been written but would add that having gone to Ajusa I do realise that the totque friction of the bolts to the head has an effect.
Thus I note they say relieve the torque by 90 degrees and then re do the totrque on each bolt. I think [!] this make sense, be it the composite gasket or the copper one - after a heat cycle or two
Richard
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PostPost by: types26/36 » Sat Jul 14, 2007 7:16 pm

[quote="paros"relieve the torque by 90 degrees and then re do the totrque on each bolt. [/quote]

Agreed, break the "toque lock" .....by loosening 1/4 turn then tighten to specified torque.....ONE BOLT AT A TIME....do not loosen all bolts and then retighten
Brian
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PostPost by: steveww » Sun Jul 15, 2007 11:16 am

Thanks for the advice. Before I can heat cycle it I need to get the !"?$%^&* exhaust back on :x There is one bolt that refuses to go back in.
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