Proper torque for tightening head bolts?
#1
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Proper torque for tightening head bolts?
We are about to start putting our 94 Regal with a 3.8 series I engine back together and have conflicting information on torquing the head bolts.
The insert that Fel-Pro sent with the new head bolts says to:
"Consult the latest OEM torque specifications as changes may have taken place since this printing" Fel-Pro printed 2000
1- tighten all bolts to 35 ft lbs
2- Turn all bolts to 130 degrees
3- Finally turn bolts 1-4 an additional 30 degrees.
I have the factory 1994 Buick Regal service manuals which state:
1- Tighten all bolts to 37 ft lbs
2- Turn each bolt 120 degrees in sequence
3- Turn 4 inner bolts an additional 30 degrees.
Which set of specs should I use?
Another question I have is about the lower intake bolts. I see many people recommending new lower intake manifold bolts (on the series II engines). I have found little information on the series I.
Thanks
Anna
The insert that Fel-Pro sent with the new head bolts says to:
"Consult the latest OEM torque specifications as changes may have taken place since this printing" Fel-Pro printed 2000
1- tighten all bolts to 35 ft lbs
2- Turn all bolts to 130 degrees
3- Finally turn bolts 1-4 an additional 30 degrees.
I have the factory 1994 Buick Regal service manuals which state:
1- Tighten all bolts to 37 ft lbs
2- Turn each bolt 120 degrees in sequence
3- Turn 4 inner bolts an additional 30 degrees.
Which set of specs should I use?
Another question I have is about the lower intake bolts. I see many people recommending new lower intake manifold bolts (on the series II engines). I have found little information on the series I.
Thanks
Anna
#2
Senior Member
This one is correct.
I have the factory 1994 Buick Regal service manuals which state:
1- Tighten all bolts to 37 ft lbs
2- Turn each bolt 120 degrees in sequence
3- Turn 4 inner bolts an additional 30 degrees.
I have the factory 1994 Buick Regal service manuals which state:
1- Tighten all bolts to 37 ft lbs
2- Turn each bolt 120 degrees in sequence
3- Turn 4 inner bolts an additional 30 degrees.
#3
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Thread Starter
Thanks carfixer007..
The head bolts also have a blue chemical on the threads and a red chemical under the bolt heads. According to fel-pro all I need to do is put a drop or 2 of oil under the head of the bolts so they wont bind on the top of the cylinder head. Of course I have to chase the threads in the block....
The head bolts also have a blue chemical on the threads and a red chemical under the bolt heads. According to fel-pro all I need to do is put a drop or 2 of oil under the head of the bolts so they wont bind on the top of the cylinder head. Of course I have to chase the threads in the block....
#4
Senior Member
Thanks carfixer007..
The head bolts also have a blue chemical on the threads and a red chemical under the bolt heads.
Hmmm....thread locker?....Have the heads been removed before?
According to fel-pro all I need to do is put a drop or 2 of oil under the head of the bolts so they wont bind on the top of the cylinder head. Of course I have to chase the threads in the block....
The head bolts also have a blue chemical on the threads and a red chemical under the bolt heads.
Hmmm....thread locker?....Have the heads been removed before?
According to fel-pro all I need to do is put a drop or 2 of oil under the head of the bolts so they wont bind on the top of the cylinder head. Of course I have to chase the threads in the block....
#5
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I do not know if the heads have been off before. I was talking about the new head bolts from fel-pro "have a blue chemical on the threads and a red chemical under the bolt heads".
Another issue I have come across is with the thermostat housing bolts. One appears to be too long.... We have kept all the bolts separated and often put them back in the threaded holes they came from so we wouldn't mix them up.. There is a long and short bolt for the thermostat housing. The long bolt is the one with the problem. It is about 2 threads too long to tighten down properly. I have chased the threads down in the intake as well as measured the depth of the bolt hole with the housing sitting on top and the bolt is just too long. We used a piece of plywood and saw horses to make our workbench beside the car under the car port. So there was no extra bolts laying around.
The upper intake uses shorter bolts and the LIM uses different size bolts. I do not remember removing a bracket from underneath the bolt and have found no pictures from the service manual showing any type of bracket or spacer under that bolt. Now the water pump and thermostat has been changed by the PO so perhaps they installed the wrong bolt but,,, they are the same type of bolts.....
Any ideas?
Another issue I have come across is with the thermostat housing bolts. One appears to be too long.... We have kept all the bolts separated and often put them back in the threaded holes they came from so we wouldn't mix them up.. There is a long and short bolt for the thermostat housing. The long bolt is the one with the problem. It is about 2 threads too long to tighten down properly. I have chased the threads down in the intake as well as measured the depth of the bolt hole with the housing sitting on top and the bolt is just too long. We used a piece of plywood and saw horses to make our workbench beside the car under the car port. So there was no extra bolts laying around.
The upper intake uses shorter bolts and the LIM uses different size bolts. I do not remember removing a bracket from underneath the bolt and have found no pictures from the service manual showing any type of bracket or spacer under that bolt. Now the water pump and thermostat has been changed by the PO so perhaps they installed the wrong bolt but,,, they are the same type of bolts.....
Any ideas?
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