torgue for the head

[teknob]

hei here from fredensborg
i have taken out the engine of my murena 2.2 ,in ned of a new head gasket.
i would like to know the torgue for the top bolts.........
and the hydrallic chaintensioner..is there a feather or some kind of o ring/package to make it keep pressure....
with regards
karsten

[teknob]

i have found it by making a search in this forum..........
90 nm for top bolts
but i stil would like to hear about the chain tensioner....

with regards
karsten

[teknob]

i found this site as wel
http://home.arcor.de/michael-tj-faust/Motor2-2.htm

[Anders Dinsen]

Hi Carsten

Sorry for not answering yesterday as I promised on the phone, but here are a couple of scans from the Tagora workshop manual:





/Anders

[Oskar]

dont they have a number for how many degrees the bolts should be turned after a specific torque?
its very rare the resistance is fixed in boltholes

[Anders Dinsen]

dont they have a number for how many degrees the bolts should be turned after a specific torque?

No, why would you want that? If you torque it up, then it's correct. If you do it more, you risk damaging the thread (at least those in the aluminium parts).

Note, by the way, that the torque list is from the Tagora which is slightly different than the Murena in certain areas: Engine mounts and sump is different, so please disregard those.

[Oskar]

well because of the step high from the bolt you get a more exact boltaxisforce then you get from the resistance in the thread. some small dirt etc can make you believe you have enough force in the head but you actually dont

[Anders Dinsen]

well because of the step high from the bolt you get a more exact boltaxisforce then you get from the resistance in the thread. some small dirt etc can make you believe you have enough force in the head but you actually dont

I understand your point there, however, if you torque a bolt up to the specified torque, then turn it a given angle (which is just the same as adding torque if you know the thread), how can that be different from just torqueing up a bolt to a (higher) torque?

I think the two methods are just different. Dirt can ruin the numbers either way... and I don't hope there will be any dirt/rust in Karstens cylinder block when he does that...

But I'm speculating here... can we find some authoritative info here?

/Anders

[Jon Weywadt]

hei here from fredensborg
i have taken out the engine of my murena 2.2 ,in ned of a new head gasket.
i would like to know the torgue for the top bolts.........
and the hydrallic chaintensioner..is there a feather or some kind of o ring/package to make it keep pressure....
with regards
karsten

Hi Karsten.
Just as important as the correct torque is that you tighten the bolt in the correct order.

Once you have them "finger tight" you must start with one bolt at the center of the head. Then you work your way around in a spiral pattern, so that the bolts are tightened from the middle of the head and towards each end.

See the page from the 505 motor manual.

[roy4matra]

dont they have a number for how many degrees the bolts should be turned after a specific torque?
its very rare the resistance is fixed in boltholes

No.  You are talking about a modern engine, where you are given a soft torque and then a torque angle which adds the final torque.  This stretches the bolts, and they don't need to be re-torqued after a set mileage.  However, with this system, you often need to replace the head bolts, since once they have been stretched, they cannot be re-used.  You must always measure the lengths, and compared with the spec.

The Murena uses older designed engines where you are given the actual torque and the bolts are not stretched.  However, you must re-torque the head bolts after approx. 1000 kms and re-set the valve clearances.  If you do not, the head gasket which will have settled, may blow.

Roy

[Oskar]

yes indeed im with you and anders. but as you say without using degreetorque after you overcome the resistance in the screw makes the torque very sensitive for dirt.
for old engines its very important to clean the holes and torque with oil on the bolts if needed. or your head wont take the force.

im more into the newer school with stretchbolt.  and they can be meassured to assure they arent passed their strechtlimit Rel

[roy4matra]

yes indeed im with you and anders. but as you say without using degreetorque after you overcome the resistance in the screw makes the torque very sensitive for dirt...

Anyone used to working on old engines knows that the head bolts are always oiled before torquing.  That is one of the pre-requisites, that was always stated in workshop manuals.

There should be no dirt on the threads unless the head as been left off and the block and bolts left lying about for some time, which is bad practice anyway.  It is also good practice to run the bolts down all holes before putting the cylinder head on the block, to make sure all liquid is out of the holes.  You often get oil and sometimes coolant, run in to the bolt holes when removing a cylinder head, so you have to clean that out.

Roy