Is 90ftlb for Supermiata head studs too much? Cracked head
#1
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Is 90ftlb for Supermiata head studs too much? Cracked head
When the head cracked I was in denial and didnt want to believe it, so I went ahead and buttoned the car up and it was ok for the first 20 miles or so before it started to idle like a subaru and blow a ton of smoke out. I had a guy comment on my YT channel that he too cracked a head on the EXACT same stud so this isnt the first time someone has had this happen. Shitty head or too much tq? You tell me.
Last edited by andyfloyd; 01-12-2021 at 09:03 PM.
#2
Which style washer did you have? There were a few threads round these here parts that stated the 90ftlbs was pretty smoothbrain for the run of small diameter washers.
SM instructions should probably stand to mention that little caveat since it was likely through history they sold both revisions of hardware.
SM instructions should probably stand to mention that little caveat since it was likely through history they sold both revisions of hardware.
#3
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Which style washer did you have? There were a few threads round these here parts that stated the 90ftlbs was pretty smoothbrain for the run of small diameter washers.
SM instructions should probably stand to mention that little caveat since it was likely through history they sold both revisions of hardware.
SM instructions should probably stand to mention that little caveat since it was likely through history they sold both revisions of hardware.
#7
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haha thanks brother, yea it shouldnt be too bad to fix. Just have to wait on the machine shop and I think Im gonna run a SCE Vulcan Split ring HG this time, that should hold my 22psi easily.
#8
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It's a huge bummer man. When putting my motor together I did a bunch of research on this, and IIRC settled on 70 ftlbs with the ARP stuff being safe. Lots of folks torquing to 80-90 without issue, but also I've read of cracked heads from this too. I want to say it was a post from Savington that swayed me to not torque them to the ARP hardware recommended spec.
#10
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Now I'm paranoid! I just finished putting my engine back together. I did a bunch of research and landed on 70 ft-lbs using ARP hardware. I've only started the engine up a few times (chasing leaks) so it hasn't been stress-tested yet. Was I too conservative on the torque settings?
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