question: to retorque or not retorque the head bolts
- Thread starter deQuincey
- Start date
BTW- I have 2 cylinder heads to replace in the
next 2 weeks- I will try out my new torque angle meter and my new torque wrench to see what I find and post the results here.
next 2 weeks- I will try out my new torque angle meter and my new torque wrench to see what I find and post the results here.
done !
hi, my little but profound problem is solved !
recapitulation:
1- i had a new head gasket from VictorReinz, and new bolts (streched type) also from VictorReinz
2- i went through the old torque instructions, the three stage torquing procedure: 40, 60, 72 N.m
3- i ran the car for 1000Km (600 miles)
4- i started asking questions, and thinking about the answers...
statement and deductions:
1- even using strech type bolts, considering the new torquing procedure i deducted that in no case my bolts should be in the plastic range of their behaviour, so a retorque IS needed to be coherent with the old torque instructions
2- i need to retorque to the final 3rd stage (72 N.m) of the old procedure, but first i MUST slightly undone each bolt to retorque them in the dynamic range
procedure:
1- warm up the engine runing the car for 1 hour
2- stop the car for three hours, check the coolant temp (35ºC), move the coolant a little by pumping it from inside the engine to the reservoir by means of the big hoses
3- remove the air filter, open the head top cover, clean each bolt head, ...
4- mark the sequence near the bolts heads from 1 to 14 to avoid mistakes in the sequence
5- paint a reference in each bolt head and in its base plate to know the final position after retorque
6- for each bolt: undo 1/4 of turn, and immediately retorque to 72 N.m
please see this video that shows it better than my words (from bolt number 5 on) , (sound in spanish, sorry)
remark: thanks all for your help, ideas, and opinions,...;-)
hi, my little but profound problem is solved !
recapitulation:
1- i had a new head gasket from VictorReinz, and new bolts (streched type) also from VictorReinz
2- i went through the old torque instructions, the three stage torquing procedure: 40, 60, 72 N.m
3- i ran the car for 1000Km (600 miles)
4- i started asking questions, and thinking about the answers...
statement and deductions:
1- even using strech type bolts, considering the new torquing procedure i deducted that in no case my bolts should be in the plastic range of their behaviour, so a retorque IS needed to be coherent with the old torque instructions
2- i need to retorque to the final 3rd stage (72 N.m) of the old procedure, but first i MUST slightly undone each bolt to retorque them in the dynamic range
procedure:
1- warm up the engine runing the car for 1 hour
2- stop the car for three hours, check the coolant temp (35ºC), move the coolant a little by pumping it from inside the engine to the reservoir by means of the big hoses
3- remove the air filter, open the head top cover, clean each bolt head, ...
4- mark the sequence near the bolts heads from 1 to 14 to avoid mistakes in the sequence
5- paint a reference in each bolt head and in its base plate to know the final position after retorque
6- for each bolt: undo 1/4 of turn, and immediately retorque to 72 N.m
please see this video that shows it better than my words (from bolt number 5 on) , (sound in spanish, sorry)
remark: thanks all for your help, ideas, and opinions,...;-)