1G High hp, which headstuds?

[Doug118]

What's the headstud of choice for the guys deep 9's or better? Are 1/2" studs needed?

 

[2gmitsueclipse]

Sounds like ARP L19's are your best selection.

Per Extremepsi:

ARP's L19 material (comparable to A1 Technologies H11 Tool Steel) is a premium steel that is processed to deliver superior strength and fatigue properties. L19 is a very high strength material compared with 8740 (standard ARP headstuds) and is capable of delivering a clamp load at 260,000 psi. It is primarily used in short track and drag racing applications where inertia loads exceed the clamping capability of ARP2000.

Because of the many head lifting issues on 4G63 blocks running in excess of 35+ PSI, a stronger stud needed to be manufactured to meet the demands of today's top engine builders and racers alike. Typical lead time on these studs is 6-8 weeks, but we have ordered these in advance and will be shelf stocking them! The L19 head stud upgrade comes with Studs, Washers, and Bolts for a complete installation. No Modification to your cylinder head or block is required as these are a direct drop-in replacement for the OEM head stud!

Yield Strength: 200-230,000 PSI
Tensile Strength: 260,000 PSI​

They are offered in both 6-bolt and 7-bolt versions for 1g DSMs. They can be purchased from multiple vendors on this site. Here is one such vendor:

http://www.extremepsi.com/store/product.php?productid=21007&cat=1848&page=1

 

[Doug118]

I ask because I can get ARP 1/2" studs for just under $100. Is this what the big dogs are running or are they just using "L19's"?

 

[2gmitsueclipse]

Your welcome to do your own research. I have already offered my suggestion. As I am sure you are aware, a build such as this, is much more involved and costly. If you are worried about $100, you are in for a shock.

 

[Doug118]

I've found 1 decent thread about 1/2 studs but it was a few years old. I'm looking to get more recent feedback

 

[donniekak]

By the time you pay for machine work, and inserts to use regular 1/2" studs, you could just drop in some l19's.

The choice does depend on if you are using a 6, or 7-bolt block. The 7-bolts can be drilled and tapped for 1/2" studs, which are a big improvement over the stock 11mm. The 6-bolts are already a 12mm size, and have to use inserts to run the 1/2" stud which is only marginally larger than stock.

I have 12mm l19's in my car. While I'm nowhere near running deep 9's I have no coolant push issues with a billet 35r at 40psi on e85.

 

[bastarddsm]

He's gonna be on stock rods donnie. If he can't get it done on a stock gasket and bolts, it's going to be putting rods out the side.

 

[Talon96fwd]

My vote goes to L19 studs. Won't regret it.

 

[Doug118]

He's gonna be on stock rods donnie. If he can't get it done on a stock gasket and bolts, it's going to be putting rods out the side.

Actually this is for an aluminum rod engine I'm having built