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Looking for recommendations for replacement studs/bolt for a 1966 Cooper S.
The cylinder head ID is 12G940.

ARP

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.

wot he sed

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. . . . . . . . . . . !

75GBP from fleebay for ARP 11 stud set

TECH396 wrote: ↑Fri Mar 12, 2021 6:43 am 75GBP from fleebay for ARP 11 stud set

Fake ARP fastners are an issue that has cropped up before.

If someone is selling them that cheap, I'd be very suspicious.

mk1 wrote: ↑Fri Mar 12, 2021 7:28 am

TECH396 wrote: ↑Fri Mar 12, 2021 6:43 am 75GBP from fleebay for ARP 11 stud set

Fake ARP fastners are an issue that has cropped up before.

If someone is selling them that cheap, I'd be very suspicious.

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.

Several folks on various Mini Facebook groups are complaining about MiniSpares studs. Has their quality changed lately?

mk1 wrote: ↑Thu Mar 11, 2021 2:20 pm 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. . . . . . . . . . . !

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.

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.

mk1 wrote: ↑Thu Mar 11, 2021 2:20 pm 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. . . . . . . . . . . !

Agreed! My engine runs them also

I think if minispares put 12 point nuts on them they'd sell more!

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?

What are they saying?

Thanks Everyone!

I will go with the C-AHT280.