jining

iTrader: (7)

Just curious who is using the 11mm L19 head studs and for how long? Im wondering because L19 steel is more susceptible to contamination and become brittle, so according to ARP the L19 material is intended for purpose built motors that are tore down at the end of the day and looked over

14mm 2000 maybe the way to go.. I want to do my build right...

Thanks again,
Aaron

JETPILOT

iTrader: (51)

I think just about everyone has the L19's and nobody has had any issues that I know of. Current thinking is that the OEM tourque to yeild head studs are the best way to go.

jining

iTrader: (7)

hmmmmm interesting, arp stresses the fact that they need to be oiled and not come in contact with moisture etc or they become brittle... not sure what to think if everyone uses them with no problem.

Whats oem torque 80ft/Ib? L19 is rated to 95 I believe, are you saying to torque them less than their rating?

Thanks for the input

JETPILOT

iTrader: (51)

I have a set of L19 head studs that were used then removed for a period of time while I built another motor. They were oiled and stored so they would not oxidize.

I am saying to use OEM head bolts tourqued to OEM spec. Aluminum cylinder heads expand much more than steel cylinder heads. All modern aluminum head motors are designed to use tourque to yeild head studs/bolts. The bolts/studs stretch when the head expands, and contracts when the head cools keeping constant tourque.

L19's are not tourque to yield.

leeboyNY

iTrader: (21)

I do.. 17psi no problem..

SnyperZ

iTrader: (10)

Yeah but would the stock studs be safe to 600rwhp?

Dynosty

iTrader: (27)

Many builds do use them as they have proven themselves through and through. I personally run them, and we use stock-size L19's in our drag car, Wongy's 700whp daily driver, etc.

L19s should not spend extended time exposed to atmosphere - which is why they come wrapped and sleeved individually. Also, if removed they should be placed in a ziploc/container with oil.

The tty stock head bolts are an interesting idea, but just because a few people dig up some info on them I'd hate to see a huge amount of 'stock tty head bolt failure' threads six months from now because everyone jumped on the bangwagon. I am going to give this one some time to be tested before I cast judgement either way - just be careful.

QuadCam

iTrader: (8)

L19 is "tool steel". It is not some exotic material. Your engine has plenty of oil slinging all of the place to keep the exposed top of the L19 studs oiled. The rest of the stud will pretty much be hidden away from any oxygen source. Also, if you have moisture in you heads, you have greater issues to worry about!!!

If you really want the best that ARP has to offer, call them up. Their custom shop will make whatever you want. You can have your own sets of L19 studs manufactuered for very reasonable rates ( as long as you buy ata least 20 sets) OR get some head studs made in their "custom age" alloy!!!! that'll be some strong stuff........you could probably apply enough torque to crack your heads!

Sharif@Forged

iTrader: (92)

Not one single issue with L19 stock sized. I think Hal summed it up nicely. I havent seen one instance of head lift with L19, stock sleeves, and HKS gasket leave our shop, or any other experienced VQ35 tuners shop. At least I can't recall one. I tuned jkenefics car with stock head bolts, and so far is holding up, but I'd like to see a longer track record.

jining

iTrader: (7)

cool, well then l19's it is thank you for the input! From what I was reading about them was making it seem like they need to be checked daily lol...

westpak

iTrader: (19)

well it would be nice to be able to go back in and retorque after a few miles but the VQ is such a pain in the *** to get at those studs