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  #1  
Old 01-15-2001, 04:24 PM
stevepeck
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What is meant by "torque them one last 90 degrees?"

Thanks.
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  #2  
Old 01-15-2001, 05:39 PM
engatwork's Avatar
busy
 
Join Date: May 2000
Location: Soperton, Ga. USA
Posts: 11,773
It means turn it another 1/4 turn

Take a good marker and put a mark on the bolt head. Turn it 1/4 turn. After I have completed all of the required 1/4 turns I mark up the top of the bolthead so I know that one is complete.
Jim
'95 E320
'97 CRV
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  #3  
Old 01-16-2001, 11:30 AM
stevepeck
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REALLY?

So after I torque down all the head bolts to the specified torque, I retorque them another 1/4 turn???

I am asking again, because this sounds wacky to me, and I don't want to screw up my engine.

Thanks again.
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  #4  
Old 01-16-2001, 02:14 PM
Stevegman
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Stretch bolts

This was recently covered on this board. The bolts will be torqued to a specific torque. Then they are turned another 90 degrees to set the final torque position. The bolts have a minimum thickness and should be measured to be sure they are in spec. When the last 90 degrees is achieved they may actually be at a lower torque setting as the bolts stretch so they cannot be tightened by torque alone. I am only an amateur and my response is paraphrased. Perhaps you can find the right thread.

Steve
'85 SL500 Euro
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  #5  
Old 01-17-2001, 12:33 AM
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Location: New Bedford, MA USA
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Steve, here is a cut from another thread..
""4. Remember to check the length of the head bolts prior to reassembly, as they can be stretched beyond specification. The head bolts are torqued in three stages, the last two being angle tightening thru 90 degrees. I would replace them. Not very expensive insurance.
5. Have the cam checked for lobe wear and end play while the head is apart.""
Angle tightening is done with fasteners that are designed to stretch as they are tightened. If memory serves me correctly, on the M103 motor, the head bolts are initially torqued to 55 ft/lbs, the angle tightened thru 90 degrees two more times. The basic concept here is that angle tightening is more accurate than absolute torque numbers because in torqueing by the numbers, it requires a lot more effort to get a fastener moving than to keep it moving (so to speak)
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1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.
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  #6  
Old 01-17-2001, 07:54 PM
engatwork's Avatar
busy
 
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Location: Soperton, Ga. USA
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good explanation jeffsr - Maybe it is my imagination but when I recently tightened up some flywheel bolts the remaining 1/4 I could actually "feel" the the bolt stretch.
Jim
'95 E320
'97 CRV
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  #7  
Old 01-17-2001, 11:29 PM
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Egatwork, I hope that was your imagination that you were feeling!!. You really shouldn't be feeling a noticeable decrease in turning force. If you are, then you have exceeded the elastic stretch limit for that fastener, which is just a silly little step away from shear separation (read as broken capscrew)..
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Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.
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  #8  
Old 01-17-2001, 11:40 PM
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Join Date: Jan 2000
Location: New Bedford, MA USA
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Egatwork, I hope that was your imagination that you were feeling!!. You really shouldn't be feeling a noticeable decrease in turning force. If you are, then you have exceeded the elastic stretch limit for that fastener, which is just a silly little step away from shear separation (read as broken capscrew)..
__________________
Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.
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  #9  
Old 01-18-2001, 08:09 AM
engatwork's Avatar
busy
 
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It was probably

my imagination
Jim
'95 E320
'97 CRV
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