Torqueing head bolts problem

Automania · Post by **Automania** » Sun Dec 23, 2012 9:46 am

Hi guys just fitting my heads at the minute. I was doing the 20nm plus 90 plus 90 system. But I had been told with care you can do 80lbft. So set my torque wrench to 80 so I didn't go above that. So I did the first 90 now I've come to the second 90 the first six all went ok, but from bolt 7 onwards there all hitting the 80 limit without barely turning! Any advice on this? Cheers mike

sidecar · Post by **sidecar** » Sun Dec 23, 2012 12:31 pm

You are using stretch bolts I take it? (I presume that you are building an RV8)

Automania · Post by **Automania** » Sun Dec 23, 2012 12:46 pm

sidecar wrote:You are using stretch bolts I take it? (I presume that you are building an RV8)

Hi yes using stretch bolts on a rover v8.

unstable load · Post by **unstable load** » Sun Dec 23, 2012 5:19 pm

Are the bolt holes thoroughly clean?
It could be you are becoming thread-bound on gunge
in the hole that is preventing it from going all the way
into the hole and torquing correctly.

Automania · Post by **Automania** » Sun Dec 23, 2012 6:00 pm

unstable load wrote:Are the bolt holes thoroughly clean?
It could be you are becoming thread-bound on gunge
in the hole that is preventing it from going all the way
into the hole and torquing correctly.

I'll be honest I never checked that, but the block was cleaned etc. before fitting.

I fitted the other head and it's done the same, so it's torqued up to 80lbft.

If I took them off again would I need new head gaskets? Cheers mike

unstable load · Post by **unstable load** » Mon Dec 24, 2012 7:12 am

I have successfully reused gaskets after torquing before, so I'd say go for it, but with the usual disclaimers.....

ian.stewart · Post by **ian.stewart** » Mon Dec 24, 2012 6:40 pm

You can easily get bad torque reading from dirty holes, even a bit of water at the bottom of the threaded hole will cause it to hydraulic, being over generous when oiling the threads can cause similar problems.