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 Post subject: Head studs or head bolts
PostPosted: Tue Mar 08, 2016 8:21 pm 
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998cc
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Location: Victoria
Rebuilding my 1098 motor which has head bolts. 1275's have head studs. Can I convert over to studs but is there any advantage in doing so.

With the bolts, the head is real easy to get off with the carbies and extractors intact.


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PostPosted: Tue Mar 08, 2016 8:28 pm 
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1098cc
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Studs are better


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PostPosted: Tue Mar 08, 2016 8:29 pm 
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religious status
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Location: near Baulkham Hills, NSW
Those old 1098 head bolts are brittle these days and snap off easy. I would fit ARP studs & nuts, if you want something cheaper the Minispares competition stud kit works OK for road motors.
You can still get the studs out for head removal, lock 2 nuts together and undo.
(Edit) watch out if buying single studs, some sold here now are absolute rubbish. [edit] They go BANG! before 30 ft/lb reached.
If buying bolts you want Grade 8 unplated ones.

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Last edited by drmini in aust on Wed Mar 09, 2016 8:50 pm, edited 4 times in total.

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PostPosted: Tue Mar 08, 2016 8:30 pm 
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SooperDooperMiniCooper ExpertEngineering
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Location: Under the bonnet son!
Not a lot of gains, unless you have a an engine pushing the performance limits. Studs can be made to a much higher quality than bolts when like are compared with like, so on highly stressed engines studs can be better. Twisting forces are also removed from the block when torquing down studs.

Bolts as you say are great for convenience, and good bolts have done the job for 56 years so you can happily stick with them if you choose to.

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PostPosted: Wed Mar 09, 2016 12:18 pm 
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848cc
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My understanding is that head bolts are a one shot deal, once torqued down they have had it as they will have stretched. Where as studs can be reused more often.

Maelgwn

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PostPosted: Wed Mar 09, 2016 3:29 pm 
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head "Bolts" OFTEN just break
i try not to use Bolts
i try to use Quality "Studs" where ever possible
the dimpled ones or the pointy (late) ones are the better of the factory ones (IMO)
otherwise as the good Doc says, ARP if you can afford it

it`s not a matter of performance to me, it`s a matter of simple reliability RE: read my first line :-)

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PostPosted: Wed Mar 09, 2016 5:28 pm 
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1275cc
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When changing to studs always check that there is enough thread to pull the head down otherwise you may snap the stud when tightening up the nut.

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PostPosted: Wed Mar 09, 2016 8:01 pm 
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998cc
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Thanks guys, ARP it is.


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PostPosted: Wed Mar 09, 2016 9:00 pm 
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The Mini King
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Minicooper4me wrote:
Rebuilding my 1098 motor which has head bolts. 1275's have head studs. Can I convert over to studs but is there any advantage in doing so.

With the bolts, the head is real easy to get off with the carbies and extractors intact.


I have in stock new old stock, head studs with the dimple on top

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PostPosted: Thu Mar 10, 2016 5:55 pm 
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998cc
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Joined: Mon Mar 07, 2011 3:29 pm
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Location: Close to Maitland NSW
John Smidt wrote:
Minicooper4me wrote:
Rebuilding my 1098 motor which has head bolts. 1275's have head studs. Can I convert over to studs but is there any advantage in doing so.

With the bolts, the head is real easy to get off with the carbies and extractors intact.


I have in stock new old stock, head studs with the dimple on top

Getm from John, you don't need the expense of Arp for a road engine.


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