Re: Re-torquing ARP headstuds
 

IDK, 400whp is about my limit w/o building the motor, and I don't really plan on doing much more than where I'm at.

Damn it shane, really?

Re: Re-torquing ARP headstuds
 

L19's! L19's! L19's! L19's!

Re: Re-torquing ARP headstuds
 

Yeah it helped to keep the heads from lifting, which was actually the failure, not the clamping force of the studs. The difference between 78 to 95 to 110lb/tq was huge.

Chris,

I'd say if you are already pushing coolant you won't stop it. The "path" has been found and it is exponentially weaker now. I would suggest to pull it apart, make sure your surface roughness value of the block and the head is what your head calls for, and put it back together. Typically ARP rates their fasteners at 75% yield strength.

Or go with a stronger (higher tensile strength) head stud.

Re: Re-torquing ARP headstuds
 

How is surface roughness measured?

Re: Re-torquing ARP headstuds
 

With a RA tester. Go to a machine shop and they should have one. They arent cheap so they might be hard to find one. The shop I work 4 has them and they are $2000+.

Re: Re-torquing ARP headstuds
 

Also, I bought the ARPs as 'the last set I'll ever need' and now look what happened. Why should I waste my time and $$ on these L19's?

Shane, what headstuds were in that 700whp evo?

Re: Re-torquing ARP headstuds
 

Is this something mobile? I mean not like I'm gonna wheel the car down there....

Re: Re-torquing ARP headstuds
 

OK keeping that mindset, why waste time and $$ on more of the same ones your having problems with right now?

You have all the info at your finger tips, it's your call dude.

Re: Re-torquing ARP headstuds
 

AMS L19s. Same as Titan, A1, etc.

Cometic headgasket. No ghetto copper spray. No O-rings.

Re: Re-torquing ARP headstuds
 

Yes it is mobile, fairly small actually. You can google it (not many results, but they are there, pics I mean)
Here is a link to a pic:
http://pracownia.mechaniki.com.pl/in...osciomierz.jpg
they come in all shapes and sizes.

Re: Re-torquing ARP headstuds
 

Wtf does surface roughness matter? Isn't the important thing FLATNESS?

I really don't think copper spray is the devil, either.

If/when I build an engine I'm gonna be surface grinding my deck surfaces down to the .0001" muahaha. I'm going for flat as flat can be.

Re: Re-torquing ARP headstuds
 

My understanding is that flatness is very important. As far as RA goes, if you are running a composite type gasket, a rougher RA could work, but if you are running any sort of MLS gasket, then RA is important as well.

Re: Re-torquing ARP headstuds
 

Anyone local have access to one of these? Anyone mobile that could help me check flatness on the block?

Re: Re-torquing ARP headstuds
 

Well, what will you honestly do to the block? I don't think it's been out, so I doubt there are any real problems with it. RA must be good enough for the factory, so I'd only worry about the head. Just check the block with a straight edge, not for roughness.

Re: Re-torquing ARP headstuds
 

My roommate has one of those certified straight edges. That's what I'm going to use to check my block's flatness when I have the head off.

Re: Re-torquing ARP headstuds
 

orly! perhaps I could borrow it for an afternoon sometime? :D

Re: Re-torquing ARP headstuds
 

I can ask him. I'm not really sure exactly what to do though. I think just lay it on the block in as many different ways as you can, and I suppose use some feeler gauges or something to measure any gaps you find?

Re: Re-torquing ARP headstuds
 

Correct.

Re: Re-torquing ARP headstuds
 

Ok, finally read through that entire thread, no discussion of copper/no copper, but I think I want to go no copper this time around.

The head studs will get replaced no matter what, but there is a tipping point for deciding between a new set of standard ARPs and the L19s: ultimately, my goals are around 400whp (dyno dynamics). Yup, so I'm pretty much there now and happy. The safe limit of the stock bottom end is around 420whp. Let's say I get the head ported while it's off, install it with L19's and get retuned and make a peachy 425whp. If for some reason the same conditions are met in which I lifted the head in the first place, and the L19's hold, what will happen? Will the bottom-end take it? Will I much rod bearings? Will I blow a hole in my block?

Re: Re-torquing ARP headstuds
 

I doubt it. Because if it's tuned right, it should be fine.