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914World.com _ 914World Garage _ Injector Tube Torque?
Posted by: 7275914911 Sep 24 2008, 07:32 PM
So I'm checking with the resident mechanics or anybody else that knows off the top of their head..
4-13mm nuts on base of each tube.
Thx in advance for all replies..
jkp
Posted by: ArtechnikA Sep 24 2008, 07:51 PM
So I'm checking with the resident mechanics or anybody else that knows off the top of their head..
4-13mm nuts on base of each tube.
Not trying to be excessively anal-retentive but there is a BIG difference between a 13mm nut and a 13mm ATF nut ...
So I'm assuming these are actually M8 fasteners.
Virtually every M8 fastener gets 2,5mKp torque.
call it 18 lbs-ft.
Posted by: 7275914911 Sep 24 2008, 08:35 PM
So I'm checking with the resident mechanics or anybody else that knows off the top of their head..
4-13mm nuts on base of each tube.
Not trying to be excessively anal-retentive but there is a BIG difference between a 13mm nut and a 13mm ATF nut ...
So I'm assuming these are actually M8 fasteners.
Virtually every M8 fastener gets 2,5mKp torque.
call it 18 lbs-ft.
They are M8 as you say. I use my 13mm socket.
Thanks for torque info.
Posted by: jk76.914 Sep 24 2008, 08:40 PM
Depends on what the mating thread it. If it's an 8.8 hardness male thread, going into steel, then 18 ft-lb would be right.
These are steel into steel, so 18 sounds right, except that the other end of the stud is anchored in aluminum. So the limiting torque is at the other end of the stud- the aluminum head. M8 steel into aluminum is only typically rated at 14-14.5 ft-lbs. And that's what the Porsche shop manual gives for all the M8 into aluminum applications that I can find.
If you tighten beyond this, your nut will be OK (steel into steel), but you risk pulling the stud from the head. Not sure what Haynes says, but I'd stick with the theory and the Porsche manual.
Looking at the Porsche shop manual, all M8 nuts on studs are listed at 14.5 ft-lbs, EXCEPT the bolts or studs that go into steel. These are listed at 18.1 ft-lbs and up-the higher ones being hardened bolts like the CV joint bolts.
Here's a torque spec that I printed out and put in my drawer with my torque wrenches. It's so consistent with what the shop manual says, that I use it now instead. Just be careful anywhere parts are clamped together that are subjected to thermal stresses- like case halves and head nuts- go with the manual on these always!
http://dodgeram.org/tech/specs/bolts/M_bolts.html
Posted by: 7275914911 Sep 24 2008, 10:32 PM
Depends on what the mating thread it. If it's an 8.8 hardness male thread, going into steel, then 18 ft-lb would be right.
These are steel into steel, so 18 sounds right, except that the other end of the stud is anchored in aluminum. So the limiting torque is at the other end of the stud- the aluminum head. M8 steel into aluminum is only typically rated at 14-14.5 ft-lbs. And that's what the Porsche shop manual gives for all the M8 into aluminum applications that I can find.
If you tighten beyond this, your nut will be OK (steel into steel), but you risk pulling the stud from the head. Not sure what Haynes says, but I'd stick with the theory and the Porsche manual.
Looking at the Porsche shop manual, all M8 nuts on studs are listed at 14.5 ft-lbs, EXCEPT the bolts or studs that go into steel. These are listed at 18.1 ft-lbs and up-the higher ones being hardened bolts like the CV joint bolts.
Here's a torque spec that I printed out and put in my drawer with my torque wrenches. It's so consistent with what the shop manual says, that I use it now instead. Just be careful anywhere parts are clamped together that are subjected to thermal stresses- like case halves and head nuts- go with the manual on these always!
http://dodgeram.org/tech/specs/bolts/M_bolts.html
Thx for cheat sheet, Jim...
I had only gone to 16 lbs fearing the worst.....things look good to my un-trained eye..new injectors, painted tubes, removed EGR(exhaust end welded closed) and new upper fuel lines and I'm back
Ready for RCR when I get rid of some rear camber for the road trip!
WooHooo
jkp
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