602 head bolt torque

[0well]

anyone know the correct head bolt torque for a 92? The chart is confusing to me= 15 nm, 35nm m 8:23. I have sorted out what a newton meter is and how to convert it to ft/pd.
thanks for your help

[sixto]

Correction, it's a 4-stage process as described later in the thread.

It's a 3-stage process. Torque all bolts to first stage, torque all bolts to second stage, give all bolts a quarter turn (IIRC the 3rd stage is 90* but you should confirm).

Try this site to convert Nm to lb-ft - http://www.onlineconversion.com/torque.htm

Sixto
87 300D

[0well]

Originally Posted by sixto

It's a 3-stage process. Torque all bolts to first stage, torque all bolts to second stage, give all bolts a quarter turn (IIRC the 3rd stage is 90* but you should confirm).

Try this site to convert Nm to lb-ft - http://www.onlineconversion.com/torque.htm

Sixto
87 300D

thats the confusing part, once we get passed the issue of either 15nm or 35nm m 8:23 it says to turn 90 degrees, wait 10 minuties and turn another 90 degrees, so is it a 3 step process or a 4 step

[sixto]

My bad. It's a 4-stage process. Give the bolts a 90* turn, wait 10 minutes, give the bolts another 90* turn. Expect sounds like a submarine imploding at depth during the 4th stage 5-stage if waiting is a stage

What do you mean by "m 8:23"?

Sixto
87 300D

[mplafleur]

15 nm
35 nm
90 degrees
10 minutes
90 degrees

I just performed the 1st two stages a few minutes ago. I'll do the rest tomorrow when I've got better light.

[0well]

Thanks sixto, I pretty much deaf, the noise won't bother me

[sixto]

You're using new bolts or old bolts within elongation spec, right?

Sixto
87 300D

[0well]

new bolts, the old ones are out of spec

[Number_Cruncher]

A useful tip for angle tightening cylinder head bolts is after the torque stages, mark the bolt heads with a dab of paint.

If you mark all the bolt heads with a dab of paint, say, pointing towards the front of the car, then, after stage 3, all the paint marks will be pointing to the driver's side (assuming LHD), and after stage 4, all the marks will point towards the rear of the car.

The reason why a dab of paint, tippex, liquid paper, or whatever is helpful is that if you get distracted midway through the procedure, [telephone call, SWMBO offering a cup of tea, or something more enticing,...] the paint marks will enable you to check which bolts you've done, and which you haven't - because once past stage 2, you can't check with a torque wrench anymore!

[mplafleur]

I finished the tightening process yesterday for my OM603.

Only one bolt did the snap! pop! while tightening on the second 90* step.

All the others were absolutely smooth and almost alarmingly easy. I attribute this to liberal amounts of oil on the bolt shoulder/head seat. I also chased down each bolt location with an old bolt. 16-17 threads down to bottom of each. I must not have had much oil on the noisy one. That one scared me. I thought it was going to break.

I used a rotation gauge to make sure I hit the 90* and used small ratchet sockets (4mm) placed upside down on the bolt of the row I just completed to make sure I didn't skip any (which I think I must have done last time).

I have just the belt tensioner and fluids remaining to complete the job tonight.

[cscmc1]

I just did this, too. I chased each hole with a tap, lightly oiled the head bolts as they went back in (they were all in-spec), and also marked him with a dab of white paint for the 90 degree stages. This helped SIGNIFICANTLY, as I needed to remove and reposition the breaker bar once or twice when clearance became an issue during the final torquing stage. That's a LOT of torque applied!

Be sure those bolt heads are good and clean. Since they're new, they ought to be, but if you have any gunk that prevents the bit from seating, you may break it. I broke two -- one when removing the bolts, and another (the official MB Hazet tool!) when replacing. I am hoping the dealership will replace the latter; it certainly should not have broken, as I was being particularly careful with it.

Good luck!

[cscmc1]

Originally Posted by mplafleur

I have just the belt tensioner and fluids remaining to complete the job tonight.

Michael -- please keep us posted. I did my head gasket, and am getting lots of nailing at idle now. Crank timing marks check out good, so I am hoping it's just in need of IP timing. I am looking into renting the RIV timing lights now.