Fixed my boost issue.....but spun a bearing this morning

[PearlWhiteR/T]

You've gone this far man. Don't get rid of it now. Take a break from it, then rip into it. Everyone loses hope once and while man.. Just focus on the end result. I wonder if that boost limiter was in place for a reason btw. I'd maybe have that tune re-verified before going for 26 psi again. How many miles on the build in those 3 years? If you got lots of hard miles out of it, sounds like a normal thing to me. Regular tear down of a purpose built motor for hard racing is pretty standard issue in my mind.

[Keyan]

There is also a 3rd revision of the crankshaft. The forged cranks made after 2000 are different. They are balanced better. By better I don't mean tighter tolerances, I mean the counterweight strategy is changed. I always use these new cranks in my builds now.
The revised version is on the right.

i bought a new crank from 2 months ago and it didnt have those things circled in red.

[donniekak]

i bought a new crank from 2 months ago and it didnt have those things circled in red.

It was nos. The ones manufactured after 2000 are revised. To get a new one from mitsu just order one for a 2000+ 6g72.

[RealMcCoy]

It was nos. The ones manufactured after 2000 are revised. To get a new one from mitsu just order one for a 2000+ 6g72.

Being as they are different part numbers, it's very unlikely you would ever get the new design if ordered by application. (until they run out of the old number and and revise the application to the new number)

I realize that's pretty much what you said, just clarifying for future readers....

[Erron Spalsbury]

(back on topic)
Ok, so wait....
Sin, how are you diagnosing this? Does it make a clank-clank sound? Or, are we just talking low on power?

[Ray Pampena]

Anyone who doesn't think you can flatten bearings without an oiling, clearance or balance issues.. step 1: build a 3/s car that makes north of 650awhp. Step 2: tune til you see knock on the sensor.. have a misfire problem or get a little greedy. Step 3: pull the pan and look

[familyMAN]

^Ray, don't you dare come here with your logic and experience.

Sin, good luck. Hope it's nothing major, but if it is a bearing, maybe you caught it early before you messed up your crank or rod. Give an update when you've checked out the oil, filter and pan.

[Sin'sVr4]

I am pulling the pan tomm morning. I was checking to see if maybe my rear turbo snapped...nope, good to go, pulled all plugs to see if maybe one grenade...nope. no metal when I drained the oil. Don't have a fitler cutter...?

BTW, my oil pressure is unchanged, solid 20psi at idle and very strong while driving 40-80psi

Drove it home (about 7 miles after hearing the knocking) and haven't started it since.

I guess we will see when I pull the pan. I will take pictures too.

I looked at my last logs and did see some knock at WOT 6500/7000 rpms. ill post some logs if I can figure it out how to post the files?

[Sin'sVr4]

ok,well...pulled the pan..bad news. looks like I pan for gold and hit it rich. found this strange bolt....thout it was a rod cap but nope. any guess? looks like a screw of some sort? so, guess my eingine is trash? or how do you know if anything is salvageable?

here are some pics







how do I know if the rods and crank are ruined? will I have to pull the engine to check?

[GTOJOE]

That piece looks like it's from the bottom of a bolt anchor/thread. Like a bolt that was too long was tightened up and caused the bottom of the "cap" to break off. Of the thread was full of crap and it pushed the bottom out when the bolt was tightened up. You're going to need to look at the block and anything attached that could have caused that. Hard to tell but is it alloy or steel?