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Old 04-27-2017, 12:44 AM   #8
Sgt.Gator
Scooby Newbie
 
Member#: 374688
Join Date: Nov 2013
Chapter/Region: NWIC
Location: Bend Oregon
Vehicle:
2005 STI
WRB

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Quote:
Originally Posted by wrxracer519 View Post
So this cliffhanger with Cobb surgeline, UPDATE!

Looking forward to following your thread. Keep it up.
OK, OK. I was waiting until a final resolution but here you go:

The overall plan. Startup run in for leaks for 20 minutes at my house. Change oil/filer. Go to Cobb Surgeline up in Portland for a dyno monitored break in culminating in a SD tune at at wastegate pressure. Then do two 6 hour track days at ORP to finish the break in with low/no boost. Back to Surgeline for the race tunes for NASA ST3- ICSCC ST- ICSCC SPM. Compete in first race at PIR May 5-6-7.

At home I started and ran the car at low-high idle for 20 minutes, then changed the oil filter. Oil looked very clean, I filtered thru a fine micron mesh screen all 8 quarts (dry sump tank holds a lot).

I took the car to Cobb-Surgeline in Portland for a dyno monitored break in cycle.

First session was great. 2,500 - 4,000 rpm for 30 minutes with no boost. We let the car cool off for 30 minutes then on second start it immediately has a loud tick/clank/knock. The sound is at idle and when the engine is under no load. As soon as it revs and is increasing RPM the tick completely goes away. The Cobb-Surgeline folks don't think it's a bearing. Their best guess is a wrist pin retainer came off and the wrist pin is loose. They used a stethoscope and are sure the sound is in the center/back of the block above CYL #4. It's definitely not an accessory drive or the dry sump pump.

At no time did the engine ever see boost or more than 4,000 rpm.

Here's the tuner's report:

"The car was warmed up to 180* F coolant temp and 150* F oil temp before I started rolling on the dyno. I began by running through 1st - 4th gears at light throttle to setup an acceptable VE curve. Then I proceeded to run through 10 miles of light acceleration in 4th gear from 2500 RPM to 4000 RPM and then engine breaking back down to 2500 RPM. Rise and repeat for 10 miles. Oil temperatures peaked at 218* F at one point but usually hung around 200* - 210* F. Coolant temps were solid at 180* - 185* F. The engine still had not seen positive boost pressure. I was monitoring fuel trims and timing corrections the entire time. I also had det cans with an additional knock sensor bolted on top of the stock knock sensor. Nothing appeared to be out of place during this short break in run. Total run time was probably around 20 - 30 min.

I took a short lunch break and then went out to the dyno room to fire the car up and get it warmed up to continue doing a few more break in miles before I continued on with the tune. As soon as I started the car there was an audible knock/clacking. I immediately glanced over at the oil pressure gauge and it was around 70psi. I went and grabbed one of our techs to get a second set of ears and he confirmed with a stethoscope that the sound is coming from the rear of the motor. That's where we called it."

A very short video clip:


I brought the car back home (180 miles each way). I thought about pulling the engine myself but decided that it would be much faster if my sponsor, Subaru of Bend, pulled it so that we can get this thing resolved without missing too many races. And also it would be better to have two independent Subaru shops involved since neither was involved in the build/installation.

Subaru of Bend got the engine out. As soon as they pulled the dry sump pan off they noticed the #2 cyl wrist pin was loose/hanging out 1/2". I got there and we took the service hole cover off and looked at the wrist pin, there was no retaining circlip. There was no evidence that it fell out and got chewed up, or was ever installed at all. There was no metal bits in the pan and we didn't see it anywhere in the block. See pics.

...

It's a little odd because we and the folks at Cobb Surgeline both heard the noise further back, above cyl #4. It's possible that one is missing too, we didn't pull off that service cover, I figured if #2 is missing that's enough to stop our examination.

The block has been shipped back to Rallispec.

I've been in communications with Dave at Rallispec. He of course wants to inspect the block himself before committing to a resolution, and I'm fine with that. I trust Dave and his company to do the right thing. So far I have no reason to think he won't take care of this. He's a respected builder here and has done other work for me in the past. I'll ask him to chime in on this thread when he's ready to make a report.

I did tell him this: "Thanks for your quick reply. Companies are made up of people and people make mistakes. A good company makes very few mistakes, but it happens. What separates great companies from all the rest is how they respond when they made a mistake.
Looking forward to your inspection report and resolution to this."

I'll miss the first two race weekends in May for sure. The problem is finding track dates where I can break the engine in, then get back to Surgeline for the race map tunes. They are booked way out in advance.

I picked the race car number 28 because in Chinese it means Double Luck. Apparently in Japanese it means something else!

I forgot to mention in the first post, I always name my race cars. The LGT Wagon was the Silver Eagle. This one is the Blue Sake Bomber.
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