Cooper S cylinder head studs/bolt replacement
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- 998 Cooper
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Cooper S cylinder head studs/bolt replacement
Looking for recommendations for replacement studs/bolt for a 1966 Cooper S.
The cylinder head ID is 12G940.
The cylinder head ID is 12G940.
Roger Williams
1966 Austin Cooper S - LHD - Wet - Personal Export
1966 Austin Cooper S - LHD - Wet - Personal Export
- iain1967s
- 1275 Cooper S
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Re: Cooper S cylinder head studs/bolt replacement
The ARP 11-stud set is £180, part number C-AHT283 from Minispares.
But for my last two S engine builds (one with a 163 head, the other with an early 940), I used the Minispares own brand EN24 11-stud competition set, C-AHT280 which is a third the price and seems to be good quality. Plus, the 6-point nut shape is more traditional for a historic engines than the 'modern' 12-point ARP style.
Note that if you're using the original 10 stud + 1 bolt rather than tapping out for 11th stud, you'll need to buy that separately.
C-AHT281 for ARP at Minispares
Regardless whether you use stud or bolt for the #11 at the thermostat end, don't torque it over 25 LbFt. I set all the rest at 42 LbFt cold then 45 LbFt after a heat cycle - you don't need to go any higher with no-stretch studs.
But for my last two S engine builds (one with a 163 head, the other with an early 940), I used the Minispares own brand EN24 11-stud competition set, C-AHT280 which is a third the price and seems to be good quality. Plus, the 6-point nut shape is more traditional for a historic engines than the 'modern' 12-point ARP style.
Note that if you're using the original 10 stud + 1 bolt rather than tapping out for 11th stud, you'll need to buy that separately.
C-AHT281 for ARP at Minispares
Regardless whether you use stud or bolt for the #11 at the thermostat end, don't torque it over 25 LbFt. I set all the rest at 42 LbFt cold then 45 LbFt after a heat cycle - you don't need to go any higher with no-stretch studs.
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Re: Cooper S cylinder head studs/bolt replacement
I have never used anything but C-AHT280 from Minispares.
Call me old fashioned / tight (delete where applicable) but £180 for a set of studs. . . . . . . . . . . !
Call me old fashioned / tight (delete where applicable) but £180 for a set of studs. . . . . . . . . . . !
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Re: Cooper S cylinder head studs/bolt replacement
Fake ARP fastners are an issue that has cropped up before.
If someone is selling them that cheap, I'd be very suspicious.
- TECH396
- 998 Cooper
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Re: Cooper S cylinder head studs/bolt replacement
I will agree Mark There's likely fakes out there but it seems consistent that eBay UK prices are at least 1/3 more than eBay USA or ebay Canada from what I've noticed.
Paul H.
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Re: Cooper S cylinder head studs/bolt replacement
Several folks on various Mini Facebook groups are complaining about MiniSpares studs. Has their quality changed lately?
Roger Williams
1966 Austin Cooper S - LHD - Wet - Personal Export
1966 Austin Cooper S - LHD - Wet - Personal Export
- Spider
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Re: Cooper S cylinder head studs/bolt replacement
I've used ARP and they are good but crazy money.
These ones Mark has suggested are almost as good and what I use now.
The original (late) stock CAM150 and CAM151 studs were also quite good, but the new replacements are just about rubbish.
- 850man
- 998 Cooper
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Re: Cooper S cylinder head studs/bolt replacement
All the engines I build get new studs from Minisport.
They are usually the A+ type with the flanged nut. But we have the normal type nuts with a thick washer for the Cooper S & "original" engines.
New Cooper S "11th" bolt, at the thermostat end were available for awhile, but have been out of stock for ages now.
ARP stud/nut kits come in std and short length so the short ones are good for heads that have had lots skimmed off them.
They are absolute overkill for anything less than a Race or Supercharged engine.
They are usually the A+ type with the flanged nut. But we have the normal type nuts with a thick washer for the Cooper S & "original" engines.
New Cooper S "11th" bolt, at the thermostat end were available for awhile, but have been out of stock for ages now.
ARP stud/nut kits come in std and short length so the short ones are good for heads that have had lots skimmed off them.
They are absolute overkill for anything less than a Race or Supercharged engine.
Restoration Specialist - https://www.facebook.com/linkautomotive
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Re: Cooper S cylinder head studs/bolt replacement
Agreed! My engine runs them also
I think if minispares put 12 point nuts on them they'd sell more!
- Hipwell
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Re: Cooper S cylinder head studs/bolt replacement
What are they saying?rogerotto66s wrote: ↑Mon Mar 29, 2021 12:31 am Several folks on various Mini Facebook groups are complaining about MiniSpares studs. Has their quality changed lately?
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- 998 Cooper
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Re: Cooper S cylinder head studs/bolt replacement
Thanks Everyone!
I will go with the C-AHT280.
I will go with the C-AHT280.
Roger Williams
1966 Austin Cooper S - LHD - Wet - Personal Export
1966 Austin Cooper S - LHD - Wet - Personal Export