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Advice Needed: Arp 12mm headstuds

Posted: Wed Aug 15, 2018 1:03 pm
by 240sx-venezuela
Hi everybody, I need some help here, I have bought a set of Rb26 arp 12mm headstuds for my ka, tapping the block to accept the new studs is an easy job, the hard part is the cylinder head wich need a little more machining for the nuts, and if you guys have some direct experience with these headstuds could you share what do you did to the head to accept the arp nuts? The new washers fits but the nut is a different tale.

Re: Advice Needed: Arp 12mm headstuds

Posted: Wed Aug 15, 2018 3:14 pm
by s14fiend
I'm in a similar position I want to add larger headstuds since the majority of people in the 4 cylinder turbo community build to accept 12mm or even 1/2" headstuds but no one has specifics on the cost of machining etc. Last average machine shop I talked to locally said $300 bucks just for the machining bringing bare engine and head. Most of the machine shops have closed down in my area since its a big city and most people lease their vehicles so it's rare to find a good machine shop and when you do they are backed up for months..... so I got that dilemma where it's like keep building KA24de? When I can buy a complete 5.3 vortec LS engine for the price of headstuds and machine work.... The upside to going bigger studs and building the KA24de is that it's still decent street beast power when tuned right for the 240sx chassis and usually a LS vortec messes up the car unless it's just a drift missile where all you care about is short wheel base and ripping tires. With turbo ka24de torque kicks in slower making traction management just a bit more feasible which is one of the many reasons I decided to stay KA.

Re: Advice Needed: Arp 12mm headstuds

Posted: Thu Aug 16, 2018 5:23 am
by 240sx-venezuela
I usually like the idea of staying with the ka becasuse I usually dont like cross branding, every engine has its potential but its something much people do, I think the machining on ka worth the money, at least for me, it will hold a lot of boost, and your right, a LS weights a lot more, Im currently doind the machining today, to find what can I do with the Nuts as this is the difficult part

Re: Advice Needed: Arp 12mm headstuds

Posted: Tue Aug 28, 2018 6:36 pm
by Toxic240
My engine machinist and builder turned down the diameter of the nuts to fit and also turned down a socket to fit between the lifters. I am using the RB26 12mm ARP2000 head stud kit on mine for reference.

Re: Advice Needed: Arp 12mm headstuds

Posted: Mon Oct 08, 2018 3:18 pm
by Keepinitpignose
I went to a well known /reputable machine shop in my area. They clearenced out between cam buckets some, also took a skim off the 12pt fasteners. ..and told me I could run pretty much as much boost as I would want having 'those headstuds' when I picked it up lol, then asked if it was a common thing for us to do.
Keep at it, I'm stoked to see another up and coming built KA

Re: Advice Needed: Arp 12mm headstuds

Posted: Sat Aug 03, 2019 8:34 pm
by 240sx-venezuela
How about the head? How did the machinist for the holes for the studs? Mine did what I think a **** job, for example, with the right tools the machinist could drill with a 31/64 drill bit wich is 12.3mm and the head would fit very well, but the machinist that did mine drilled the holes like 13.5mm and if I install the head without the fasteners I can move the head, and I imagine the head could do that under 30psi of boost

Re: Advice Needed: Arp 12mm headstuds

Posted: Sat Dec 14, 2019 7:42 pm
by s14fiend
Go bigger headstud a 12mm is for pussies......

Re: Advice Needed: Arp 12mm headstuds

Posted: Mon Dec 16, 2019 9:01 am
by 240sx-venezuela
s14fiend wrote: Sat Dec 14, 2019 7:42 pm Go bigger headstud a 12mm is for pussies......
:D I already have 12mm headstuds in hands, its more than enought for my hp goals LoL

Re: Advice Needed: Arp 12mm headstuds

Posted: Tue Jan 07, 2020 8:39 pm
by s14fiend
Oh I hear you....... what ARP material are you using on those 12mm ? That’s what’s important not the size.........

Re: Advice Needed: Arp 12mm headstuds

Posted: Tue Jan 07, 2020 8:41 pm
by s14fiend
s14fiend wrote: Sat Dec 14, 2019 7:42 pm Go bigger headstud a 12mm is for pussies......

I said this cause I’m pretty sure larger with high quality material might be the best option for one and done to hold the head down.

Re: Advice Needed: Arp 12mm headstuds

Posted: Fri Jan 10, 2020 11:57 am
by 240sx-venezuela
s14fiend wrote: Tue Jan 07, 2020 8:41 pm
s14fiend wrote: Sat Dec 14, 2019 7:42 pm Go bigger headstud a 12mm is for pussies......

I said this cause I’m pretty sure larger with high quality material might be the best option for one and done to hold the head down.
8740 I think, I bought them 2 year ago, they hold up great AFAIK, my plan is 600hp maybe a little less