Cylinder head bolts specs
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From: Winter haven
Cylinder head bolts specs
I have a ? I have an 03 sohc v6 4.0 ranger and the specs on the cylinder bolts say step1 turn 25ft lbs step2 turn an additional 90degrees and step 3 turn another 90degrees? After I turn the first 25 ft lbs I can barely turn it a quarter turn more don't get it? in desperate help please
These are torque to yield(TTY) bolts so need to be new
Yes, in sequence tight to 25ft/lb which is just above hand tight, this is to seat the head on the dowels
And do the 2 smaller 8mmm heads bolts to 25ft./lb as well at this time
Then in sequence rotate each 12mm head bolt 90deg(1/4 turn)
Then repeat, in sequence rotate each 12mm head bolt 90deg(1/4 turn) again
The bolts stretch out to hold head tight, which is why they can't be reused
The TTY bolts are better but also save engine builders like Ford a ton of money, it was expensive to calibrate torque wrenches daily, also pay some one to do the tightening sequence
With TTY a machine can do all 8 or 10 head bolts in sequence and at the same time
90deg is 90deg, no calibration needed, the 25ft/lb is just snug and not all that important
Yes, in sequence tight to 25ft/lb which is just above hand tight, this is to seat the head on the dowels
And do the 2 smaller 8mmm heads bolts to 25ft./lb as well at this time
Then in sequence rotate each 12mm head bolt 90deg(1/4 turn)
Then repeat, in sequence rotate each 12mm head bolt 90deg(1/4 turn) again
The bolts stretch out to hold head tight, which is why they can't be reused
The TTY bolts are better but also save engine builders like Ford a ton of money, it was expensive to calibrate torque wrenches daily, also pay some one to do the tightening sequence
With TTY a machine can do all 8 or 10 head bolts in sequence and at the same time
90deg is 90deg, no calibration needed, the 25ft/lb is just snug and not all that important
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