matt15 New Member 17 Member For: 11y 2m 8d Posted 18/01/15 02:13 AM Share Posted 18/01/15 02:13 AM HelloI have been trying to research this question but cant get a definitive response so...I am wanting to make 550rwkw to 600 on my ba. at the moment its has 375rwkw with forged bottom.I cant recall where I saw it but there was a thread on another site regarding issues with head lifting even with the 12mm studs so naturally people went with the atomic 14mm studs.I am wanting to know is there a point either psi or kw where the 12mm studs wont suffice..?I know there was a issue a few years back where it was occuring alot but then the tuners figured it out.Basically I want to know if its necessary to go to 14mm or 9/16" for the power I am wanting.I also recall that the atomic 14mm studs were not made by arp. There was a 9/16"arp head stud set from another car that could be used but I dont recall the make.If anyone has any details or experience I would appreciate it..I need as much information as I can get.cheers. Link to comment Share on other sites More sharing options...
turbotrana Member 2,586 Member For: 21y 11m 1d Gender: Male Posted 19/01/15 03:17 AM Share Posted 19/01/15 03:17 AM Personally I don't think a 12mm stud should pose problems. I have torqued down a 12.5mm stud with over 200ft/lb, in actual fact the torque wrench went to 200ft/lb and after that used a breaker bar to the point where the nut deformed and I didn't have issue with the stud. You need to make sure that it is a non-wasted shank stud.I think you should look at more what head torque values are to be used, MLS gasket brand and whether or not you use any sealant on the head.Personally, this is not a proven recipe as I have not tested at 550rwkw and above level, marriage put a stop to that.I don't particularly have faith in the Ford MLS gasket. Its too thin IMO, no give. I would try the more expensive Permaseal one with a couple of more layers. It has more give. Or you could even take two ford gaskets to make up a 5 layer MLS gasket.I would be using 100ft/lb+ on the studs. Have used 120ft/lb, but you need to have the engined torque plate honed with the machining using your proposed head torqueing value. There are possible issues of bore distortion but the falcon block seemed OK to me.I do like using the 3 bond sealant on the deck and head. I have used copper and steel gaskets and have not had water leak using the white 3 bond 1211 sealant.Also get some really thick and widest washers laser cut for the head bolts. Alluminium does sink with those pissy ARP washers that you get. They don't need to be hardenned washers 1 Link to comment Share on other sites More sharing options...
CHLAXN Donating Members 932 Member For: 16y 9m 9d Gender: Male Location: north QLD Posted 19/01/15 08:09 AM Share Posted 19/01/15 08:09 AM I have arp 12mm head studs I have just got for my engine build also brought atomic over size washers aswell. Was tossing up going 14mm but when I have some extra dollars might just go the age 625+ 12mm studs but aren't cheap and can't find a part number anywhere. Link to comment Share on other sites More sharing options...
matt15 New Member 17 Member For: 11y 2m 8d Posted 22/01/15 01:07 AM Author Share Posted 22/01/15 01:07 AM Thanks for the Information People Link to comment Share on other sites More sharing options...
matt15 New Member 17 Member For: 11y 2m 8d Posted 22/01/15 01:08 AM Author Share Posted 22/01/15 01:08 AM Personally I don't think a 12mm stud should pose problems. I have torqued down a 12.5mm stud with over 200ft/lb, in actual fact the torque wrench went to 200ft/lb and after that used a breaker bar to the point where the nut deformed and I didn't have issue with the stud. You need to make sure that it is a non-wasted shank stud.I think you should look at more what head torque values are to be used, MLS gasket brand and whether or not you use any sealant on the head.Personally, this is not a proven recipe as I have not tested at 550rwkw and above level, marriage put a stop to that.I don't particularly have faith in the Ford MLS gasket. Its too thin IMO, no give. I would try the more expensive Permaseal one with a couple of more layers. It has more give. Or you could even take two ford gaskets to make up a 5 layer MLS gasket.I would be using 100ft/lb+ on the studs. Have used 120ft/lb, but you need to have the engined torque plate honed with the machining using your proposed head torqueing value. There are possible issues of bore distortion but the falcon block seemed OK to me.I do like using the 3 bond sealant on the deck and head. I have used copper and steel gaskets and have not had water leak using the white 3 bond 1211 sealant.Also get some really thick and widest washers laser cut for the head bolts. Alluminium does sink with those pissy ARP washers that you get. They don't need to be hardenned washersHow many kw were you making with the 12mm studs..? Link to comment Share on other sites More sharing options...
turbotrana Member 2,586 Member For: 21y 11m 1d Gender: Male Posted 22/01/15 01:35 AM Share Posted 22/01/15 01:35 AM (edited) I was only running petrol, so not much KW, as I said, not proven recipe on ethanol horsepower.There is also a thread somewhere on the tuning side of the equation in helping the head stay on. Jet (buttplug) can fill you in on that one. Edited 22/01/15 01:38 AM by turbotrana Link to comment Share on other sites More sharing options...
JETURBO ...JD TUNING ADELAIDE... Gold Donating Members 23,708 Member For: 16y 9m Gender: Male Location: Adelaide Posted 22/01/15 01:39 AM Share Posted 22/01/15 01:39 AM No time for people who cant play games hahahaha Link to comment Share on other sites More sharing options...
CHLAXN Donating Members 932 Member For: 16y 9m 9d Gender: Male Location: north QLD Posted 22/01/15 04:03 AM Share Posted 22/01/15 04:03 AM (edited) Got some more of my atomic gear for motor build today.. Here is a look at the standard ARP washer for 12mm head studs and an Atomic oversize washer for 12mm head studs. Very big difference between the 2!!! Edited 22/01/15 04:04 AM by CHLAXN Link to comment Share on other sites More sharing options...
jimmixr Donating Members 686 Member For: 14y 6m 12d Posted 22/01/15 06:46 AM Share Posted 22/01/15 06:46 AM Running these ^^^ with the atomic studs and 3bond sealerStandard Ford head gasket. Link to comment Share on other sites More sharing options...
gaz097 Bronze Donating Members 1,752 Member For: 13y 7m 10d Posted 16/04/15 04:32 AM Share Posted 16/04/15 04:32 AM Anyone know an answer to this question yet? Link to comment Share on other sites More sharing options...
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