E30 M52

[B C]

I got a wave of motivation, went out and fixed the stripped threads, re-installed the cam.

Guess what happened?

Yep, stripped another one!

[Earl]

So are you sure you have the proper torque specs? I don't want to seem like I'm second guessing you but I find it very hard to believe that they would put a torque spec that dangerously close to the yield of that thread in aluminum.

[B C]

11 foot pounds/132 inch pounds, certified calibrated torque wrench that goes from 40 to 200 inch pounds so I am right in the middle of the torque wrench capacity and everything to

[B C]

(Reserved for future post about stripped threads)

[B C]

(Reserved for future post about stripped threads)

[B C]

(Reserved for future post about stripped threads)

[straight6pwr]

(Reserved for backhanded comment about you doing torques wrong)

[B C]

No

[GunMetalGrey]

I want to believe you aren't doing something wrong, but I'm having a very hard time doing so. 
I've rebuilt many of these motors, and the only time I had a stripped thread was the small torx screws that go into the timing cover. 

Those cam caps are a glorified hand tight, so I don't quite see how you are having so many issues.

[B C]

I've been a ding-dong many times before but I promise that in this instance I am 100% right and the cylinder head threads are 100% wrong.

Mitch mentioned my torque values may be in yard-pounds [emoji23]

[i_love_cars]

Let me know when you are ready to work on this again. I will stop by and supervise to provide the final word on whether or not you are right or the cylinder head threads are.

[patsbimmer1]

You know there are different tightening torques for M6, M7 and M8 bolts right?  Are you sure you don't have M6 bolts?  Those are only torqued to 7ft/lbs.

[jc43089]

How do you have the camshaft?  Could you take a picture of what you are doing?  I am confused (easily).  When I swapped an intake cam I had it turned so only the #1 cylinder lobes were down and tightened that cap first to compress the valve springs and my helper was holding the cam with a wrench to prevent it from turning while I installed the other caps and torqued it down.  I think I might have needed longer bolts because the studs weren't long enough to get the nuts started. and then once all of the others were installed I rotated it so there was no pressure on that spot and removed the bolts and put the studs back on.  It was a while ago and I was installing an m54b30 cam.

[B C]

patsbimmer1 said:

You know there are different tightening torques for M6, M7 and M8 bolts right?  Are you sure you don't have M6 bolts?  Those are only torqued to 7ft/lbs.

Most definitely M7. 

jc43089 said:

How do you have the camshaft?  Could you take a picture of what you are doing?  I am confused (easily).  When I swapped an intake cam I had it turned so only the #1 cylinder lobes were down and tightened that cap first to compress the valve springs and my helper was holding the cam with a wrench to prevent it from turning while I installed the other caps and torqued it down.  I think I might have needed longer bolts because the studs weren't long enough to get the nuts started. and then once all of the others were installed I rotated it so there was no pressure on that spot and removed the bolts and put the studs back on.  It was a while ago and I was installing an m54b30 cam.

This is exactly how I am doing it. Cyl #1 lobes are the only ones under any valve spring pressure. Bearing cap #2 is installed first with a1/4 turn on each nut until its flush with the cam tray, then all other bearing caps are installed flush, then torqued evenly (1/4 turn on each nut) until it reaches 11 ft-lbs or the threads strip, whichever comes first.

At this point I am planning on having to repair every last one of them. If in some horrible nightmare I manage to start pulling-out the threads on the repaired holes, that's the point at which I will part it out, ban myself, lease a new Prius, and disappear from the car community forever.

[jc43089]

Strange.  Is this on just one of the cams?  Did you remove the studs from the head ever?  I'm just speculating, could the studs not be fully seated and the stud is turning in the aluminum rather than the nut turning on the stud?  Just grasping at straws.  I guess I would just put inserts in all of them at this point.

[Jdesign]

Snap said:

At this point I am planning on having to repair every last one of them. If in some horrible nightmare I manage to start pulling-out the threads on the repaired holes, that's the point at which I will part it out, ban myself, lease a new Prius, and disappear from the car community forever.

Thanks. I just spit water all over laughing.

Could it maybe justtttt MAYBE be that your torque wrench is out of calibration? I know you said that it is certified and calibrated, but it can EASILY get out of calibration if you leave it out and your offspring decides to play light saber wars with it or you simply tightened it to 100ftlbs and leave it like that over night for example.

[B C]

Stripped 6 or so with a small beam type torque wrench, went out and bought this Husky click style specifically so that the torque value I need lands right in the middle of the range and includes a calibration certificate.

The other 4 or 5 have been stripped with the new wrench

[m42b32]

Out of curiosity, do you have the correct torque value? I have heard that sometimes the bentley/hanes/etc can be off at times

[jc43089]

If the torque value keeps stripping them then don't go so tight?  Insanity is doing the same thing over again expecting different results

[patsbimmer1]

m42b32 said:

Out of curiosity, do you have the correct torque value? I have heard that sometimes the bentley/hanes/etc can be off at times

He's right.  I checked it against BMW's repair procedures.