M20 tightening torques

[ss109]

I searched through the Bentley but on my head rebuild I could not locate the following torque specs:

Camshaft oil seal housing to head
various studs (exhaust, intake, and cover)

[turbodan]

The only bolts you need to torque on the M20 are the ones holding the connecting rod caps on and the ones holding the head onto the block. I like to torque main bearing cap bolts too, but I'm sure thats not really necessary.

[mooseheadm5]

Basically, make them tight enough. If you must use a torque wrench on everything, there are standard tightening torques for each bolt size, and those charts are available online.

[rodpaine]

Extract from company standard BMW N 600 02.0, 20/10/97
Torque specs are for M20, unless shown other wise.

Camshaft bearing cap
M6 bolt - 10 Nm/7.4 ft lbs
M7 bolt - 15 Nm/11 ft lbs

Sprocket to camshaft
M10 bolt - 65Nm/48 ft lbs

Cylinder Head Cover
M6 bolt - 10 Nm/7.4 ft lbs
M7 bolt - 15 Nm/11 ft lbs

Connecting Rod Bolts, New, washed and very lightly oiled
M10/M30 - 55 Nm/40.5 ft lbs
M20 - 20 Nm/14.8 ft lbs
S38 - 30 Nm/22.2 ft lbs

Intake manifold on cylinder head
M8 bolt - 22 Nm/16.2 ft lbs
M7 bolt - 15 Nm/11.1 ft lbs

Exhaust manifold to cylinder head. Screw connections
on exhaust with Molykote HSC compound coat
M6 bolt - 10 Nm/7.4 ft lbs

Drain plug for coolant on engine block
M14 x 1.5 - 25 Nm/18.5 ft lbs

-Rod

[WVe28]

http://www.e28calendar.com/Misc/bmw_torq.pdf

[ss109]

http://www.e28calendar.com/Misc/bmw_torq.pdf

Perfect! Thank you!

[rtuite]

The spec on the rod bolts is WRONG, and cost me the bottom end of my motor. It should be 20 Nm/14.8 ft lbs + 70 degrees.

Don't make the mistake I did. It held up fine until I started getting my tune honed in, then it stretched the rod bolts, ate a bearing, dropped oil pressure in the motor, and ruined all my brand new bearings and my crankshaft. This is about a $1,000 screw up. Learn from my mistake. Double check everything. Even thought this is one of the first pages that comes up in a Google search for M20 torque specs, it is wrong.

After 3 years of building this car & sinking every spare dime into it, this is absolutely heartbreaking.