Darin's 80q…Alive...

[PRA4WX]

I'm extremely happy it didn't happen in Vegas or on the way home. I might have left it in Vegas forever, if that happened.

Like I said earlier......first on the list!

It would be pretty sweet tdi powered!

J/K Darin! Get it running! 8)

[quattro87]

I'm extremely happy it didn't happen in Vegas or on the way home. I might have left it in Vegas forever, if that happened.

Like I said earlier......first on the list!

It would be pretty sweet tdi powered!

J/K Darin! Get it running! 8)

Get it back running Darin.....we are already scheduling a TDI swap! You are right though Micah....it would make a sweet high miler!!

[85oceanic]

Like I mentioned, I'm thoroughly convinced my torque wrench is CRAP.

I have one of these and I absolutely love it...



http://www.ccjdigital.com/snap-on-touts ... -wrenches/" onclick="window.open(this.href);return false; ... -wrenches/" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

Time for an upgrade man.

[85oceanic]

I'm extremely happy it didn't happen in Vegas or on the way home. I might have left it in Vegas forever, if that happened.

This would be the one time where the saying "what happens in Vegas stays in Vegas?" rings true?

[BlackBox]

NM

[Audilard]

I'm actually quite happy after pulling the head. Definitely not worse case scenario, but also not best.

The head gasket blew. Did some damage to the head, but no damage at all to the block, pistons or cylinders.




I've inspected all the cylinder walls and turned it completely over. Everything is smooth.

Yes, I believe that head can be repaired, but I'm also looking at the tapping the spark plug and putting an insert in. I'd like to think ahead and build a head with inconel valves to avoid something happening in the future. Not exactly in the budget, but nothing ever is. I might sell one of my sets of 4x108 wheels to build the head.

I also found this when removing the fuel lines and rail....



All in all, I gotta say I'm relieved and the car is not for sale.

[savagerocco]

Glad the line did t leak and catch fire....... I can swing by tonight and grab the head and get you welded back up. Need to pull it apart before heating it up so great time for valves. Figure 250 for inconel that is almost a best case senerio if you ask me....

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[Dave]

Lol I called at 10 to give a hand.... Way too slow for Darin these days! Glad you got it off and that you are happy with how it went.

[savagerocco]

Are you still running stock pistons? I know you did rods but I thought there were aftermarket pistons too.

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[quattro87]

That's great Darin!! You are getting much faster.....don't you just love V-bands? Glad to see it's just a head repair/replace, but sad to see it's not for sale. LOL

[scubadave]

Well thats interesting! That is an easy repair compared to having to tear the block down or finding another block. Lets find you an alternative pressure fitting to use for your fuel lines. I would rather see you use SS or brass than alum, this is getting rediculess. let me know when you are going back together and you can borrow my snapon torque wrench.

[speeding-g60]

that head is fixable it looks like to me.

true story, the head on mine right now had the SAME THING happen to it. welded, surfaced, and it works fine.

[Hank]

<whispers> Oring the block!

[Audilard]

Stock 3b pistons. Going to go with Inconel exhaust valves. EM and IM and WM are off the head. It's ready for pick up.

It's going to back on the road sooner rather than later!

[TheArchitect]

Thats not just a simple HG failure, you need to ask yourself why you burned through the fire-ring on the gasket and melted the aluminum.

Looking at the ceramic on the plugs could help you decide if you killed it with det or EGT.

[speeding-g60]

mine was cyl pressure building too fast we think. 5k rpm 30 psi to 5700 rpm 45 psi was too quick.

[loxxrider]

Thats not just a simple HG failure, you need to ask yourself why you burned through the fire-ring on the gasket and melted the aluminum.

Looking at the ceramic on the plugs could help you decide if you killed it with det or EGT.

Agreed.

mine was cyl pressure building too fast we think. 5k rpm 30 psi to 5700 rpm 45 psi was too quick.

I'm trying to wrap my head around why this matters...

[AudiSport4000]

Yikes, thats some nutty stuff, Darin. Kudos on getting it torn down quickly. Hope to see it back on the road soon.

[speeding-g60]

mine was cyl pressure building too fast we think. 5k rpm 30 psi to 5700 rpm 45 psi was too quick.

I'm trying to wrap my head around why this matters...

we think.... we built a completely new motor, tuned to 40 psi all was good. hit 4th gear once, did the same exact thing, and lifted/blew it up again in the same place and the same fashion. from the same reason. had to have been as everything else was all new, everything but the turbo/cams. new block/head/pistons/headbolt-studs/rods/valves all of it. dont have any proof of det, EGT were fine, luck would have it i guess. from then on, we dialed back the timing, made it safer so i could get seat time, and well i havent done it since.

thinking timing/cyl pressure too aggressive. the same tune worked just fine on the same motor in the rabbit with the 35R. it was the rabbit motor that first died, in those pix. thats how it happened, too. left the tune for the rabbit in there and hit the bigger turbo.

but back to Darin, that is just some insight as to what happened to me/us with the same exact damage.

[Hank]

Thats not just a simple HG failure, you need to ask yourself why you burned through the fire-ring on the gasket and melted the aluminum.

Looking at the ceramic on the plugs could help you decide if you killed it with det or EGT.

Sorry Jared, I have seen this happen on more bone stock engines/management than I have seen on modified engines. Simply HG failures, nothing more. Hot steam at 2000psi will cut through MLS and aluminum faster than you can blink. If the head wasn't flat, something fell on the surface during reassembly, or if a headstud was not torqued correctly, a simple headgasket failure will happen.

That said, I would love to look a the plugs in more detail, and have better pictures of the piston tops and combustion chambers.

Hank

[85oceanic]

Nice work Darin! Keep at it man!

[TheArchitect]

Thats not just a simple HG failure, you need to ask yourself why you burned through the fire-ring on the gasket and melted the aluminum.

Looking at the ceramic on the plugs could help you decide if you killed it with det or EGT.

Sorry Jared, I have seen this happen on more bone stock engines/management than I have seen on modified engines. Simply HG failures, nothing more. Hot steam at 2000psi will cut through MLS and aluminum faster than you can blink. If the head wasn't flat, something fell on the surface during reassembly, or if a headstud was not torqued correctly, a simple headgasket failure will happen.

That said, I would love to look a the plugs in more detail, and have better pictures of the piston tops and combustion chambers.

Hank

Where would you have hot steam at 2000psi coming from?
If its 2000psi cutting through the MLS gasket and the head, would that not have had to come from the cooling system?

I think you see this as the common location becuase its the thinnest section between the combustion deck of the head and the cooling passage.

I have seen that type of failure on many different engine types and its nearly always as a result of combustion temps above the melting point of the alloy used in the head. The steel on the gasket itself is burnt, not cut and the melting eventually burned out the non cyl side of the gasket exiting out the side of the head. The burn came from the cyl to the pasage and then out the back.

[Audilard]

I wasn't smart enough to pull the plugs out and remember which one was which so here are all the plugs except for #3 which I know was #3 because it had the aluminum stripped out on it. I installed these brand new plugs in Vegas after tuning which eliminated the missing, did some pulls on them and then drove them about 450 miles home and to work. You can't tell much difference in any of them.



Tuning was done in Vegas, but I told Marc I was at about 4500ft elevation vs. whatever Vegas is. Injectors are 650cc Siemens. Do they look like I'm running lean? Does VEMS have a barometric pressure adjustment internally?

[Hank]

In non detonation events( stock ECU's, stock turbos, stock boost levels and stock components), heads get cut out like this because water gets into the combustion chamber via a weak headgasket, a warped head due to excessive heat, or debree on the surface of the deck. That water is sucked in on off stroke and expelled out at high cylinder pressures on the compression stroke. This is vaporized water with mass at this point carrying a tremendous amount of energy, along with the 1600 degree "burn" you reference. 1600 degree water plus a modest 2000psi at 24psi that Darin is running makes for a very powerful jet stream. If given given the option of least resistance into the coolant system, the pressure will cut out the soft alloy in the head, and the .010" layers of steel to get there. 1600 degree flame mixed with vapor water will make it look like a burn, but it is just a waterjet part! It is erosion. No aluminum was melted, contrary to your theroy, but eroded away. Look on the back of both failures. The backboard of the waterjet eroded into back of the failure.





Now how that water got into the chamber to begin with? I still wanna know if Darin ever put water back into the car after changing turbos. I wouldn't be surprised if detonation events in catching the overboost situation in tuning didn't break the seal on the MLS in Vegas. MLS gaskets are extremely sensitive to having that rubber coat broke on the metal. If a poorly torqued head allowed for the weakest part of the head( the #5) to leak and get into the chamber, when cylinder pressures exceed what the compromised gasket can hold, that water now becomes a cutting media. If it was indeed detonation, pump gas detonation would show trademark detonation marks in the piston and combustion chamber. If it was EGTs, the fragile gt30r turbine would show damage. With both checking out, I gotta look at a headgasket failure.

[quattro87]

Those plugs look good to me Darin. Even if you weren't running barometric compensation, at altitude, if anything you would be a bit on the rich side as compared to the 2k elevation of Las Vegas.......less dense air/same tune. Aggresive tunes can sometimes be hard on turboes at elevation as the turbo will overspin trying to reach boost with the thinner air. I am beginning to think just a bad gasket and a tune that was pretty aggressive, but not overly so.