Re-tensioning Head Down.

HONES · petrol head Joined: 04 Feb 2002 Posts: 1786

Ok, its about that time i do it.

What sequence do i do it in? 1-8 front to back opposite what?

i got the torque wrench set to approx 74 pbft or ftpb. something like that...

so i gotta crack them and then tension them up...
anyone?

taa
matt

HONES · petrol head Joined: 04 Feb 2002 Posts: 1786

oh yeh, drain radiator before hand.

it'd be ok to use the same rocker cover gasket wouldnt it??...just a lil grease or silicon to seal her up is cool right.

MJ · newbie Joined: 03 Nov 2001 Posts: 8

What Engine is it ?, If G161, if Starting from the middle of the head, ie between pots 2 and 3. its those head bolts first. so from front of the engine it would be like this LHS ( your looking towards the rear of the engine ) 9,5,1,3,7 and RHS 10,6,2,4,8. With 9 and 10 being the two little bolts ( inside head ) that bolt through the head into the top of the timing case don't over tightn these as you will either strip the thread out of the T/Case or shear the bolts off Sad

.

9 5 1 3 7
* * * * *
FNT Rear
* * * * *
10 6 2 4 8

When Tensioning the Head down it's a three stage process ( diff torque settings each time ). From Memory you have to crack the bolts first then do the re-tensioning.

MJ.

MJ · newbie Joined: 03 Nov 2001 Posts: 8

opps damn typo " With 9 and 10 being the two little bolts " should read " 11 and 12 " .....

Stock TE · backyard mechanic Joined: 12 Mar 2002 Posts: 853

Almost right
10 6 2 3 7
* * * * *
FNT Rear
* * * * *
9 5 1 4 8
and when retensioning dont you only tighten it to the third stage of tightening (not sure on this bit)

MJ · newbie Joined: 03 Nov 2001 Posts: 8

LOL yeah it doesn't really matter which side you start just as long as you continue the same way all the way through. Hmmm i think so, been to long since i last did one. That was the old engine that was in 95 when i did that one. It was just a standard 60th over, full rebuild, pistons, rings ect.. lumpy cam, port'n'polished head, electronic ign. Got a new project about to start soon, an EFI DOHC G200.

Stock TE · backyard mechanic Joined: 12 Mar 2002 Posts: 853

This is my dads car, dont have to worry about installing the engine as its completly standard, http://www.hotgemini.com/cgi-bin/gallery2.cgi?action=sv&vid=485

Poida · Posted: Fri Jan 16, 2004 12:13 pm Post subject: Re: Re-tensioning Head Down.

Ok I have in front of me a genuine ISUZU manual for the G161Z engine. It shows the correct tension sequence as:

F 7 3 2 6 10 R

T 8 4 1 5 9 R

It states to tighten in two steps, firstly to 8.5 kg-m then finally to 10 kg-m.

I can't find reference to cracking the head bolts before retorquing and I've never found any reference manual suggesting cracking a boly prior to retorquing. I'd not suggest you crack a torqued bolt. Just retorque to check it is at the correct final torque setting. It may not need any adjustment. Retorquing is a form of checking.
_________________
I try to tackle one day at a time, but often several days attack me at once.

(The views I present are my own and NOT necessarily of the administrators or other members of this site.)

Racegem · backyard mechanic Joined: 30 Jan 2002 Posts: 987

Depends who writes the book...
Start with the middle two and work out from there, either clockwise, anti-clockwise, or opposites, it doesn't really matter. The critical thing is to get the tension evenly spread across the head rather than all down one side or from one end. That's why when you're fitting the head the first time, you start with a small tension setting and do the lot, increase the setting and do them again, and so on... just don't do the two at the front the same as the rest! Very Happy

I would agree that you shouldn't have to crack them first, you're only checking that they're at the final tension.

Sprocket · Posted: Sun Jun 17, 2007 9:02 pm Post subject:

To do it right ..start from the center as if you are tensioning the haed for the first time . Now one at a time crack the head stud/bolt and tension to the final setting DONT CRACK ALL OF THEM AT ONCE.!!!
BINGO you have now tensioned your head

HONES · petrol head Joined: 04 Feb 2002 Posts: 1786

oh ok, cheers

READ THE DATE OF THE ORIGINAL POST

YOUR HELPING ME FROM WHEN I POSTED IT 3 YEARS AGO

MR_GEMI · Posted: Tue Jun 26, 2007 11:13 am Post subject:

how good was 3 years ago
_________________

LOK15 · Posted: Tue Jul 10, 2007 10:57 pm Post subject:

MR_GEMI · Posted: Wed Jul 11, 2007 4:05 pm Post subject: