LMM: What Grade headstuds to use

CRAWLEN

Member
Sep 29, 2017
134
1
16
Hi Guys,



Im sure this has been asked before but cant find it.


im currently building a lmm for about 700 hp. possibly more with these internals.


Durastar crank
carillo rods
mahle cast pistons

arp main studs
all h series bearings
socal push rods
new lifters
cam
and alot of other bits


planing on running a danville 68mm stg2 turbo with 100% injectors.
with a 10mm stroker pump.


would the standard arp head studs be fine for this ? or am i better off buying the custom series ones ?
 

Chad006

Drag racer wannabe
Feb 12, 2015
311
5
18
Goodlow, B.C.
I’m running the standard arps on the setup in my signature, block is o ringed though. Haven’t had issues with lifting heads yet, and these studs are on their second torque.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,681
5,835
113
Phoenix Az
Should be fine. If you start pushing much higher boost pressure or drive pressure than that 68 alone does, then it would a concern. There are guys running 80+ psi of boost on standard arp’s.
 

CRAWLEN

Member
Sep 29, 2017
134
1
16
Sweet cheers for that guys means I can now stay with what I have and not need to buy another set.
 

CRAWLEN

Member
Sep 29, 2017
134
1
16
So i have to ask at what point would you run the custom series headstuds. Is there a power range or psi or drive pressure that would be the limits of the standard arp studs
 

CRAWLEN

Member
Sep 29, 2017
134
1
16
Bump.


So still haven't gotten an answer for my last question, at what point would you use the custom age series. As im contemplating it to just be safe with this engine im building. Is it possible the 68mm stg2 can lift the head ? As i seen mark has got it make over 700hp would like to do it as i will have the fuel system capable but that will be just a max effort tune. So should i just bite the bullet and order the better studs ?
 

ikeG

Oughta Know Better
Apr 19, 2011
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Western PA
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625's shouldn't be necessary if your sealing surfaces are flat. But it's up to you, never a bad idea to go overboard.
Bump.


So still haven't gotten an answer for my last question, at what point would you use the custom age series. As im contemplating it to just be safe with this engine im building. Is it possible the 68mm stg2 can lift the head ? As i seen mark has got it make over 700hp would like to do it as i will have the fuel system capable but that will be just a max effort tune. So should i just bite the bullet and order the better studs ?

Sent from my XT1585 using Tapatalk
 

ikeG

Oughta Know Better
Apr 19, 2011
2,465
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Western PA
www.facebook.com
I would rather do firerings and cheap studs than good studs and no rings.

If you are running compounds and pushing them hard, that's a good sign you need both the 625's & firerings

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CRAWLEN

Member
Sep 29, 2017
134
1
16
I'm not really planning on ever going compounds. And I want to stay away from oringing or fire ringing. It's just been getting a few diffrent answers on what the studs can handle. When I was asking about turbos. I would just hate to do all this work to then lift a head.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,681
5,835
113
Phoenix Az
I'm not really planning on ever going compounds. And I want to stay away from oringing or fire ringing. It's just been getting a few diffrent answers on what the studs can handle. When I was asking about turbos. I would just hate to do all this work to then lift a head.

that is going to be much more determined on tuning, machine work, and how you achieve your power than just head studs.

you are way over thinking this if you are just going to run a 68mm single.....
 

CRAWLEN

Member
Sep 29, 2017
134
1
16
that is going to be much more determined on tuning, machine work, and how you achieve your power than just head studs.

you are way over thinking this if you are just going to run a 68mm single.....




Not trying to over think it just getting mixed answers. Engine is getting completely built and mark will be tuning it. But everyone here says the cheap grade is fine but then on another post being told the opposite. I would oring the block but not sure if my machinest can do it. I'm in Australia so aftermarket support and knowledge on building these engines is a bit thin. That's why we might have issue oringing
 

NC-smokinlmm

<<<Future tuna killer
May 29, 2011
5,201
363
83
At Da Beach
Most just run factory head bolts so...

You will be fine with standard studs. Majority who stud did so bc they had bad gaskets on LLY and early lbz...
 

CRAWLEN

Member
Sep 29, 2017
134
1
16
Who is telling you to run the more expensive studs?
I wouldn't say they were telling me to, it was just was just more leaning to it amd being told to oring the block with standard arps. That had me concerned, and if i could get away with running the high grade studs with out oringing.


Sorry about it all guys just trying to collect enough info so my self and my machinest can put this engine together and it be reliable