Re-torquing ARP headstuds - Page 3

**scheides** · 05-12-2009

Quote:

Originally Posted by ecoli

Just get the A1 L19 studs and follow the directions that come with them. They are cheap for the Evo/7-bolt compared to 400-500 for a 6-bolt or 600-800 for a Supra.

Quote:

Originally Posted by FattyBoomBatty

IMO, I'd really assess your goals with this car. Will you really be taking advantage of the L19's or would you be alright with regular arps?

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?

4g63tcrazy · 05-12-2009

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

niterydr · 05-13-2009

Quote:

Originally Posted by MustGoFaster

I assume you are using the right TQ spec? They are different for which type of lube you use. You can also try a slightly higher torque. We found it effective on Josh's car at delaying head gasket failure to a higher HP level.

You may want to lossen the nuts up and take them off just so you can besure they are nice an lubed up.

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.

**scheides** · 05-13-2009

How is surface roughness measured?

Mwolf83 · 05-13-2009

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+.

**scheides** · 05-13-2009

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?

**scheides** · 05-13-2009

Quote:

Originally Posted by Mwolf83

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+.

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

**Halon** · 05-13-2009

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.

**Shane@DBPerformance** · 05-13-2009

Quote:

Originally Posted by scheides

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?

AMS L19s. Same as Titan, A1, etc.

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

Mwolf83 · 05-13-2009

Quote:

Originally Posted by scheides

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

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.

sleepydsm · 05-13-2009

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.

**Halon** · 05-13-2009

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.

**scheides** · 05-13-2009

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

FattyBoomBatty · 05-13-2009

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.

**Halon** · 05-13-2009

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.

**scheides** · 05-13-2009

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

**Halon** · 05-13-2009

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?

niterydr · 05-13-2009

Quote:

Originally Posted by Halon

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?

Correct.

**scheides** · 05-14-2009

Quote:

Originally Posted by 4g63tcrazy

Read from like the 3rd page on of the link I posted. Also when you do the copper spray you need to do it VERY evenly and you can easily over spray in some area's making the surface uneven.

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?

FattyBoomBatty · 05-14-2009

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