Chopshop13
Member
As the title suggests i need Head bolt torque settings using High tensile cap screws on my eab? They have high tensile washers under them.
Regards
Regards
eab Head torque settings using High tensile cap screws?
- Thread starter Chopshop13
- Start date
Chopshop13
Member
well as you could imagine, bolts of different tensiles stretch differently and torque isnt the objective pressure is.
Having stated that, and using my big big brain, the pressure required for the compression of the head is equal to the pressure resisted by the threads in the deck. and at said pressure there will be a friction force between both bolt and block. follow me now. So 'torque' is simply achieveing that level of friction and subsequently head pressure. So tensile strength or strech of bolts wont factor in... untill the thing gets hot.
Your thoughts?
Having stated that, and using my big big brain, the pressure required for the compression of the head is equal to the pressure resisted by the threads in the deck. and at said pressure there will be a friction force between both bolt and block. follow me now. So 'torque' is simply achieveing that level of friction and subsequently head pressure. So tensile strength or strech of bolts wont factor in... untill the thing gets hot.
Your thoughts?
Chopshop13
Member
Ive read a list of different torque settings for different types of bolts, god knows where.
34PKUP
Well-known member
The use of higher tensile strength bolts than required only allows you to tighten to a higher torque to give a higher clamping power. ( getting too agressive could mean pulling threads out of block)
Torquing to the original spec's will give the same clamping force as the original bolts.
Using washers seems to indicate the use of aluminum heads, if so torque to the spec's required for those heads.
Torquing to the original spec's will give the same clamping force as the original bolts.
Using washers seems to indicate the use of aluminum heads, if so torque to the spec's required for those heads.
Using bolt or stud tensile strength as a basis for determining torque to apply to the head fasteners is inappropriate. The determining factors should be, in this case, the overall construction of the unit. If everything is clean and lubed I suggest 45 ft. lbs. and never more than 50.
Chopshop13
Member
Thanks, as i said id seen a list with torque settings for different fastners but thinking about it for two minutes dispelled that. thanks.
Chopshop, If you over torque it, you could cause bulges into the bore area. Flaheads are weak in the top of the block. This is why some engine builders use torque plates. It means that the bores are finished with bulges in them, so that the bulge caused by torqueing the heads is compensated for. Some piston manufacturers give two different specs. One for use with torque plates, and a greater clearance for when torque plates are not used.
JWL had it covered.
JWL had it covered.