Blown head gasket.

[Fred]

As per title i have blown the head gasket on the rear bank :angry:. Haven't heard of these as being a common failure. Its using more coolant than fuel.
Anyway, does anyone have the specified loosening/tightening sequence of the head bolts (front & rear bank. I'll do both) & the torque settings/degrees(if applicable.) also the loosening/tightening sequence of camshafts, & tightening torque. I will get both heads machined, Put a VRS kit through both heads, buy a cooler kit, replace engine mounts, replace leaking seals in transfer case & replace all main radiator hoses/thermostat & replace valve lifters. . All input & help greatly appreciated.
Regard.Fred.

 

[Fred]

Also if possible, R&R sequence for valve guide seals.

 

[jungle]

Bugger, what a pain, mine let go today as well, not the Leggy though Let me know how you get one?

 

[Fred]

I still can' t source the torque setings for anything. Does anyone have this info handy?
Fred.

 

[SiliconAngel]

One of the things that SHOULD have been in the workshop manual, but a great deal of critical info like this was left out, frustratingly. It SHOULD be in the Japanese version, then you just need to find someone who can translate it for you (or find the relevant section and use machine translators).

 

[jungle]

I still can' t source the torque setings for anything. Does anyone have this info handy?
Fred.

Fred,

I dont know the specs but i would suggest 60-70ft/lbs would be pretty close. I use 70 on my RB25 and 30.

Couple of things you can try, ring Dave at RPW he may know. Ring Mitsubisi and ask what it is for the 6G72. I would suspect that the V6 range will be very similar?

Head studs sequence wise, just start in the middle and work your way out in a circular pattern. Any cylinder head is the same with this aspect.

Cams, take it VERY SLOWLY. investing some time here is critical, it's very easy to snap cams so just undo each bolt a small amount each time, again working from the middle to the outside, same when you re tighten.

Hope that helps.
Let us know how you get on?

 

[jungle]

After a bit of searching the 6G72 head bolts are torqued to 80ft/lbs or 110nm.

 

[jungle]

Also found this but not sure how to interpret it. It says 20Nm +120 degrees +120 degrees.
http://www.mivec.co.nz/tech/6A1_Engine_Manual.pdf


Now it's for the 6A1- series motors but it's a little strange in that is doesn't give a spec, rather a small spec 20Nm and then tighten a further 120 degrees twice?

I think 80ft/lbs would be safe for you. I'll be using that when i re-assemble my engine

 

[Kitty's VR4]

These are the 6A13 settings from supplemental 2002 Jap Manual

Rocker Covers are 3.4 Nm
Rocker Gear Cam Caps are intially tightened to 10～12 Nm then to 20 Nm
Heads are 20 Nm 120° +120 (so tighten to 20 Nm then tighten by a further 120°)

 

[Fred]

I did think they were angle tightened. A lot of jap cars are. Will give that a try. Cheers. Will let you know how i get on. Fred.

 

[jungle]

What Kitty says is correct, found an old thread from 2007 http://www.mivec.co.nz/forums/viewtopic.php?f=29&t=5092&view=next
that says the same thing.

this is it here.....

*edit* found what seems to be a head bolt torque spec, but it has it in 7 phases! 22ft lbs then 36ft lbs then 54ft lbs (this is the amount of torque which broke the bolt), then back 180 degrees then 15ft lbs then 90 degrees then a further 90 degrees!

 

[Guest]

Part of the reason for me getting rid of my car was because of a leaky head-gasket on the rear bank. Mine was also using more coolant than oil, but it was dripping a fair bit when I traded it in.
I contemplated spending the money to get it done, but after spending $5k+ in the last 6 months with zero performance gains, I'd had enough. I miss it though...