Torquing Heads
08-24-2011, 10:01 PM
#32
Rennlist Member
What I've learned, over the years, is that the people at Porsche aren't stupid....they might have "issues" with a "current" design of hardware, but they know the problems and they are working on a solution, if they do have a problem. I also learned that consistant stretching of the hardware is very critical....actually way more critical than the "torque number".
Even pressure, properly stretched, is the best senario one could ever imagine. I try to make sure that this happens as perfectly as I can make it happen.
Even pressure, properly stretched, is the best senario one could ever imagine. I try to make sure that this happens as perfectly as I can make it happen.
so was how much room they allowed for the headers to be removed in the car. 1" more on each side would have made the car a dream to work on.
08-24-2011, 10:03 PM
#33
Rennlist Member
Thread Starter
08-24-2011, 10:03 PM
#34
Rennlist Member
and thats the main thing right there. if we were all so concerned for the proper stretch, i think we all would get new bolts every time we pulled the heads and did angle torque. no way the bolts stretch exactly the same the second time you do a 90 90 tightening sequence after an engine has seen several thousand heat cycles. 
08-24-2011, 10:21 PM
#35
Rennlist Member
Thread Starter
So I take it Mark that you aren't a fan of the 15ftlbs/90/90?
08-25-2011, 01:27 AM
#36
Former Sponsor
and thats the main thing right there. if we were all so concerned for the proper stretch, i think we all would get new bolts every time we pulled the heads and did angle torque. no way the bolts stretch exactly the same the second time you do a 90 90 tightening sequence after an engine has seen several thousand heat cycles.
I wouldn't dream of telling you guys everything I do to keep the heads on....you'd really freak out.
08-25-2011, 01:30 AM
#37
Former Sponsor
Not trying to nitpick, but I still don't get this. If the torque went down because of the washer spinning, but the bolt is turned to the required angle, it just means it was easier to turn the bolt because of less "washer friction" on the bolt head. The bolt is still turned to the desired angle resulting in the desired clamping force. Maybe I didn't understand your explanation though.
I didn't make up the rules....I just follow them and it seems to work, for me.
08-25-2011, 01:33 AM
#38
Former Sponsor
yes, i agree and would like someone to find some part of what you are saying that is not true!
torue going down doesnt effect stretch Greg. its angle and distance, not force in the case of the head nuts on the S4. the ony thing that might be valid as a reasonable assumption, is that the washer moving removes material , but there is no way two quarter rotations moves 1 thou of material away from the washer seat. I think you have thought this one into a hole.
torue going down doesnt effect stretch Greg. its angle and distance, not force in the case of the head nuts on the S4. the ony thing that might be valid as a reasonable assumption, is that the washer moving removes material , but there is no way two quarter rotations moves 1 thou of material away from the washer seat. I think you have thought this one into a hole.
08-25-2011, 01:34 AM
#39
Rennlist Member
im not a fan, because it doesnt take into account bolt stretch and material variances. (for mainly reusing old bolts which Greg doesnt do, but i do , because its been done before and no one has had issues. )
However, it would be interesting to see the number of head gasket failures and see if they coorelate with the number of heads that have been removed and have had the bolts or studs removed.
However, it would be interesting to see the number of head gasket failures and see if they coorelate with the number of heads that have been removed and have had the bolts or studs removed.
08-25-2011, 01:37 AM
#40
Rennlist Member
08-25-2011, 10:16 AM
#42
Rennlist Member
Thread Starter
Well I am lead to another question now. I have been through a few torque sequences now with my engine. When I do 15/90/90 and the washer doesn't move, I don't get the same ending torque on each bolt at the last 90. Do I need to wrap my head around this or just forget it?
08-25-2011, 11:16 AM
#43
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Well I am lead to another question now. I have been through a few torque sequences now with my engine. When I do 15/90/90 and the washer doesn't move, I don't get the same ending torque on each bolt at the last 90. Do I need to wrap my head around this or just forget it?
I use the old bolts and then put the new ones in for the final torque.
08-25-2011, 01:26 PM
#44
Rennlist Member
what type of torque are you getting on the last 90? i know when i was doing the studs, where they are 15, 35, 64ftlbs, the last step, losen from 90 dgrees back off , and re-torque, was just a little more than 90 degrees and the nuts were loose at backing off 90degrees. so thats really about 1 90 .
anyway, what did you see on the last 90 as far as ft-lbs. did you have a torque wrench on the angle meter? i wouldnt worrry about it. no shop will replace the studs on a rebuild unless they are bad. (at least very few) replacng them at about 7 bucks each x 20 = $140, is an expense that is just not needed.
just angle it out and walk away. you will be fine!
Mk
so thats really about 1 90 .anyway, what did you see on the last 90 as far as ft-lbs. did you have a torque wrench on the angle meter? i wouldnt worrry about it. no shop will replace the studs on a rebuild unless they are bad. (at least very few) replacng them at about 7 bucks each x 20 = $140, is an expense that is just not needed.
just angle it out and walk away. you will be fine!
Mk
Well I am lead to another question now. I have been through a few torque sequences now with my engine. When I do 15/90/90 and the washer doesn't move, I don't get the same ending torque on each bolt at the last 90. Do I need to wrap my head around this or just forget it?
08-25-2011, 01:57 PM
#45
Rennlist Member
Thread Starter
what type of torque are you getting on the last 90? i know when i was doing the studs, where they are 15, 35, 64ftlbs, the last step, losen from 90 dgrees back off , and re-torque, was just a little more than 90 degrees and the nuts were loose at backing off 90degrees. so thats really about 1 90 .
anyway, what did you see on the last 90 as far as ft-lbs. did you have a torque wrench on the angle meter? i wouldnt worrry about it. no shop will replace the studs on a rebuild unless they are bad. (at least very few) replacng them at about 7 bucks each x 20 = $140, is an expense that is just not needed.
just angle it out and walk away. you will be fine!
Mk
so thats really about 1 90 .anyway, what did you see on the last 90 as far as ft-lbs. did you have a torque wrench on the angle meter? i wouldnt worrry about it. no shop will replace the studs on a rebuild unless they are bad. (at least very few) replacng them at about 7 bucks each x 20 = $140, is an expense that is just not needed.
just angle it out and walk away. you will be fine!
Mk
Wife is helping on the final torque to hold the washers with an awl and to steady the block.