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MG Midget and Sprite Technical - Cylinder head nuts torqueing wet or dry
Good evening gentlemen When searcing for the ultimate answer to my question: is torqueing the cyl. head down done with dry or wet thread, it is it obvious that it is a sensible question on line with engine oil discussions. The studs are the drilled type. Any suggestions here? |
Jan Kruber |
Allways oil the threads and the washers with engine oil---unless they are ARP studs , then use their moly lube and their tension spec |
William Revit |
I never lubricate head nuts/studs and always torque to 50 ft lbs in 3 stages, 25 - 40 - 50 then back off 1/4 turn before final tightening to 50. |
Chris at Octarine Services |
Really--what about main studs,on Clevo V8s the main caps get 105 ft/lb ,if you try one of them dry they stop at about 85-90 and won't go any further, you can feel them ,they just stop, you could pull 110 or so on a tension wrench and they won't move,but it will still be 85-90, pull it out and lube the thread and away they go Sorry but i believe in lubing up---- willy |
William Revit |
Jan, any chance of a photo of the drill marks on the studs (some had numbers on IIRC). |
Nigel Atkins |
Willy - we were talking midget head nuts / studs. Lubing these can lead to over stretching the stud, pulling threads out of the block and stripping nut threads. |
Chris at Octarine Services |
Nigel - some had dimpled ends, others had 22 stamped on them - either were safe up to 55 ft lbs which is what I always did fast roads heads up to. |
Chris at Octarine Services |
Thanks. It's what the drill spots look like as I think mine are drill spot but I would like to compare with those that are confirmed as such to be sure. |
Nigel Atkins |
I agree with Chris. It has always been my understanding that standard A series studs nuts should be torqued dry as lubrication can lead to over-torquing with the possible consequences that he describes. |
Peter Blockley |
Here's a pic of the stud(s) - no stamping, only drill holes. Seems that there are different points of view like when I "googled" the subject, I only want to do it as right as possible. I understand both points, now I just have to choose - half dry, half wey ? LOL |
Jan Kruber |
Thanks for photo I can't remember mine being as clear cut as that, I'll take more notice next time. |
Nigel Atkins |
Chris-Jan
My humble apologies-- I contacted my Mini mate (full size) and he sent me this---and said they did them dry ,new during assembly ------------------ 'If you're using standard spec studs/nuts, do them up with NO lubrication to 45lb ft. If you oil the threads, do them up to 42lb ft, or using a moly-based oil, 40lb ft. If using either Mini Spares up-graded stud/nut set OR ARP, use a lubricant – and preferably a moly-based one – and torque ‘em up to 45lb ft.---no more as extra pressure puts the pressure on the whole gasket instead of on the sealing rings around the bore where it's needed most' ------------------ It'd be a different situation for a MLS gasket I suppose but there you go- So dry it is---new to me, you learn something every day - I think I should stick to Chevs where I belong ''NOTHING revs like a Chev'' willy |
William Revit |
I was always surprised that my (former) local Mini ‘shop oiled the head studs when assembling. |
Dave O'Neill 2 |
This thread was discussed between 30/10/2018 and 31/10/2018
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