Lessons Learned From Steve

Well the thread from the post mortem of Steve's motor has been locked. I don't know if it was for the direction it was heading or if people just want it buried and to forget the troubles that it's life and death caused.

I don't know if Steve has an interest in having the issue put to rest or maybe has just succumbed to the pressures from the masses.

I myself am ready to accept the turbo boost theory. DB makes that case very clear and there is no doubt in my mind that a situation as he described in the previous topic had occurred.

I wonder though, how much the likelihood of a defective engine casting may have had on the failure. IMO this is what contributed to the catastrophic destruction of Steve's motor.
In all probability, Steve gave the motor the push it needed to fail earlier than it would have without any meddling.

I have held the VNT 15 Turbo in my hand and it's hard to believe the connecting rods would fail before it. (Unless VW's swiped trade secrets from Trabbi.)

IMO Some sort of hydraulics problem would much more likely have had an impact on the failure and there was some sloping around going on in Steve's motor (thus the previously seen shavings) and the overboost/burn had an effect on the sleeve dropping, creating failure.
Many were adamant about placing the blame squarely on Steve and were open about his questionable changes being the root. I find them more accurately to be a branch.

Finally, I think a non opinionated metallurgist would be able to tell for sure and it would sure be nice to have one at least take a peek at it. Just for finality.

The worthwhile discussion of this has mostly been by email. the forums are just too volitile to get any worthwhile information across without personal attacks. If you only know what has been posted, your driving blind. half of what happened isnt even known because of varying stories and personal attacks.

Its time to drop it. when the complete anaylsis of the engine is complete, it will be posted fully and truthfully. until then, there is no need to keep guessing about whos fault this was. It doesnt matter for now. the car runs.

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr> I have held the VNT 15 Turbo in my hand and it's hard to believe the connecting rods would fail before it. <hr></blockquote>

Well, you gotta look at not just the turbo and the boost pressure, but the totality of what can happen.

Sure, a turbo can only produce so much pressure and voume of airflow. Short of eating a bolt, the turbo will die of overrev, if it goes high enough or spins too fast long enough.

But that little turbo can easily supply more boost than the engine can handle safely at least in certain conditions, well within the limits of the turbo itself.

In the right conditions of load, temperature, altitude, rpm, speed etc, you can fill a cylinder with enough air and fuel and start it burning soon enough to send the rod out the bottom of the pan.

Dinking with all the stuff that tells the engine controller what is going on can lead it to think it is ordering a safe amount of boost and fuel and injection timing.

Larger injectors, incorrect readings from air sensors, more agressive operation from a chipped computer that might not be aware of the bigger injectors and dinked MAF and so on is just a recipe for breaking something.

I bet it was fun while it lasted though.

Well VW let me be the first "Fire-Eater"/"conspiracy theorist" to apologize for being wrong about Steve's motor.

That wasn't so hard.

Will you have someone apologize for the shoddy service and rotten customer service throughout most of the continental U.S. so many have addressed during this trying time?

First of all I agree that only way to know what caused the engine to grenade is to perform the autopsy, which Drivbiwire has done.

However, others posting possible scenarios is just as important, as often times when diagnosing a failure the investigator may ignore evidence based on preconceived ideas. Keeping an open mind and listening to other scenarios may help avoid jumping to conclusions. That said, I think Drivbiwire pretty much nailed the root cause of the problem, i.e. overboost.

I'm not sure what was meant by hydraulics playing a factor, but i haven't heard of any evidence pointing to this. Hydrolock would twist the crank. Fluid residue (whether water, engine coolant or oil) would be in the intake, and none was reported. As far as a weak engine casting, again I haven't heard of any evidence supporting this. No engine block is designed to withstand a lower end which grenades (okay maybe some race cars, with wrapped balistic blankets around the flywheel and crank). All four con rods were reported to be bent in the same manner. No head gasket failure would cause this, no wrist pin failure would cause this. Uniform damage to the con rods in the manner reported could only result from exceeding the design cylinder pressure during the power stroke, probably from a combination of overboost and overfueling. Overrevving would typically stretch the con rods failing the lower cap, not bend them in compression. I've seen overboost/overfueling manifest itself it two ways, uniformly bent con rods and/or uniformly melted pistons, with scored cylinder walls.

By everyone posting problems and people providing different view points and ideas, almost any problem can be solved on this forum. What a great place.

OK, stupid questions here, but...

With the problems some people have keeping the IC hoses on with unmodified cars how was TS's IC hose able to stay on at 40 PSI?

Why would the push rods crumple from compression from over boost before you blow out a hose somewhere along the line?

Probably easy answers, but I am interested in hearing them anyway.

jorpet,
I don't know about the IC hoses coming off, never heard of anyone having a problem with them unless they weren't installed correctly in the first place. (Or I wasn't listening?)
The overboost situation would not cause the hoses to blow off because the valves would be closed when the piston reaches its' maximum compression and then ignition of air fuel mixture.

AutoDiesel,
This is the current thread commenting about the problem. http://forums.tdiclub.com/NonCGI/ultimatebb.php?ubb=get_topic&f=17&t=003118, but I have seen it mentioned before. Even thought the hose isn't subjected to the entire pressure of the cylinder, it is still over double the designed max for the hose and clamp.

turbo steve had all custom metal IC lines... i think he might have been using custom connectors and threaded style clamps also. I just dont know, but its certain that whatever he was using didnt come loose... so why push the IC hose issue?

Lessons Learned:

How about keeping things simple?

Giving VWAG Engineers more credit.

Don't mess with the MAF cylinder.

OEM Air System is more efficient than you think.

Paper air filter still flows plenty of air - 168+ HP

OEM exhaust still allowed TDI RS (wanna be) engine to breath nice and easy.

11mm Pump and 205's allowed engine to still pull strong at 5,200 RPM's when the ECU pulled back on the reigns.

11mm pump creates less work for the turbo, whose boost is lower than a 10mm counterpart.

No fuel cooler is needed for manual transmissions when upgrading to a 11mm pump because of it's efficiency versus slippage of a torque convertor in an automatic transaxle.

205 injectors take more load off the turbo than smaller injectors.

No matter how hard new engine was worked, highest oil temp was 205*F.

When water temp gauge reaches 190*F., oil temp is almost always 50*F. cooler and naturally takes longer to warmup.

Oil pressure at idle is 19 PSI.

Oil pressure at startup is over 80 PSI.

TIT (Turbine Inlet Temperature) gauge averaged 650*F - 700*F. when doing 80 MPH / 3,000 RPM's.

Shutdown of new engine is at 400*F. or lower, instead of using 20 - 30 second turbo cooldowns.

"I think a non opinionated metallurgist would be able to tell for sure."

Mike:

You have a good point, but I just want to move on. If an engine part did indeed fail, I'm sure I'd never get a dime out of VW anyways because of the mods I've performed and all the publicity on the Forum.

Moving on with the new engine is much more important for me now than being overly concerned about the cause of the failure, which we already know the most likely was the cause.

I've always admitted that my tinkering was part of the failure, how much? I didn't know until Pete provided some basic details on how the ECU works with the primary sensors.

Thanks to all for your support!