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| Head stud tension? https://www.ausmini.com/forums/viewtopic.php?f=2&t=66874 |
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| Author: | IndigoBlueCooperS [ Tue Nov 09, 2010 9:53 pm ] |
| Post subject: | Head stud tension? |
I am using a set of 1275 A+ head studs and nuts on a stock 1100 engine. What tension should they be tightened too? I assume this to be dry? Thanks |
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| Author: | GT mowog [ Wed Nov 10, 2010 5:35 am ] |
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These studs are identified as having a tapper on the UNF end. 50 ft/lbs is the vactory rcommended torque for these as long as you also have the matching nuts, these are the ones with the built in washer, flanged. |
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| Author: | Hunter2 [ Wed Nov 10, 2010 6:08 am ] |
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Coarse thread inserted hand tight into block... I had just arrived when a friend snapped a head stud he was torquing into the head ("tighter the better" philosophy). His eyes went wide open.... |
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| Author: | IndigoBlueCooperS [ Wed Nov 10, 2010 6:12 am ] |
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No tapper on the short (and intermediate) studs, only on the long ones. The nuts have the built in washer. 50 is a bit more then the old 40 or 42! Is 50 OK for the old blocks? |
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| Author: | GT mowog [ Wed Nov 10, 2010 6:38 am ] |
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IndigoBlueCooperS wrote: No tapper on the short (and intermediate) studs, only on the long ones. The nuts have the built in washer. 50 is a bit more then the old 40 or 42!
Is 50 OK for the old blocks? Do your short studs have a mark in the centre on the UNF end that looks like a centre pop? Guide: Plain top 40 ft/lbs (stock early mini) with plain nuts Bolts - throw them in the bin 'Centre Marked' 42 ft/lbs (Cooper S), nuts have 8 marked on to some of the flats Tapered Top 50 ft/lbs (A+), flanged nut 50 is OK on the older blocks if you have the correct studs. I would recommend with ANY studs counterboring the block stud holes, the top 3 or 4 threads off, this reduces the 'volcano' effect happening on the block deck face. I would also suggest that you do not mix studs (ie all early, all cooper S, or all A+) and use either Cooper S of A+ Nuts. If you are going to mix studs, tension them all down the same, to the 'weakest' stud / nut. If you are fitting the extra studs as per Cooper S, the one over the water pump only torque to 25 ft/lbs. |
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| Author: | drmini in aust [ Wed Nov 10, 2010 6:10 pm ] |
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If you are going to fit roller rockers, do not use the A+ flanged nuts there unless you machine the flange diameter to that of the nut corners. They won't fit otherwise... they hit the rockers. I saw a set of Minisport rockers that had been fitted to an A+ head (now owned by an ausmini member) by the engine seller in UK- he had done the nuts up, then used an ANGLE GRINDER to put 2 flats on each nut. What a dill... 
And you re-torque the nuts, how???  keep angle grinder handy I guess. 
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| Author: | TK [ Wed Nov 10, 2010 6:16 pm ] |
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and make sure there is enough thread. I have seen too many broken studs that were tightened down only to find out the reason the stud broke was that the nut had run out of thread. 
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| Author: | GT mowog [ Wed Nov 10, 2010 6:24 pm ] |
| Post subject: | Re: Head stud tension? |
IndigoBlueCooperS wrote: I assume this to be dry? Thanks Not 100% sure what your meaning here, but oil the threads before fitting and torquing. IndigoBlueCooperS wrote: No tapper on the short (and intermediate) studs, only on the long ones.
There are only the Long and the Short Head Studs, they are all 3/8" diameter. Not sure what your describing here with the 'intermediate' studs? |
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| Author: | IndigoBlueCooperS [ Wed Nov 10, 2010 7:56 pm ] |
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So should the threads be oiled? Historically I have done them dry. Oil would increase the bolt stretch. I have two 1275 A+ engines. Both had one of the short studs slightly longer at the heater tap end. This is to enable the coil bracket be held onto the stud with an additional nut. None of the short studs have the tapper on the top like the long studs did. So it sounds like oil the thread and 50 ftlb. |
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| Author: | drmini in aust [ Wed Nov 10, 2010 8:14 pm ] |
| Post subject: | |
Oil under the nuts too...
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| Author: | awdmoke [ Wed Nov 10, 2010 10:29 pm ] |
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drmini in aust wrote: Oil under the nuts too...
That's the way I like it too
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