another episode of WTF happened. Looks like something went through this engine as there are zero signs of similar activity in cyl 2 and 3. All valves are clean as a whistle as well. The only sign we had was a plug(#4) had a dent in the rim like something impacted it, the plugs otherwise were clean, no specs or chipping. Dont ask about a log, there was a mix up and it was deleted. Lean cut was turned on for this initial outting. This pass was a 6.55 at 120. Does this look like detonation to anyone here?



cyl 1


cyl 4


Chamber


turbine

 

What's the compressor wheel look like? Something definitely went through the engine. Time to tear it all apart and look around. Check your IC, piping, TB, etc. And send me the log!

 

I'm gonna take a stab and say your running a twin scroll manifold and when the damage happened it happened to be on the 1-4 stroke and pulled something in those two cylinders.

 

no.... looks like some thing went thru motor... check t body screws egt probes etc....

 

agreed debree in the system

 

I lost the log jason

I checked TB screws and the typical stuff. Yes its a "twin scroll" 6766 Turbo. Compressor wheel has no new knicks besides, it would be 99.99999999% impossible to get something that big through my Garrett intercooler core.

 

I'm not sure I'm following how an egt probe would make it into a cylinder. But it is very clear something metal went through that cylinder. TB screw seems most likely. Just happened to a friend of mine.

 

debris*

 

lol

also cylinder 1-2 looks to be cracked between them or is that an optical

 

debris

jajajajaja lol

 

Was there any welding slag etc in the charge pipes that maybe broke free and got sucked in there? Definitely had some foreign object through there man.

 

no welding slag, nothing has been changed fab wise either in over a year.

 

Things break down over time homie. Unless you have found the exact cause of it, don't rule out anything coming loose, breaking off, getting sucked through, etc.

 

egt probe eats up turbine wheels, doesnt normally get into motor, but basicaly saying check eveything... I would also look at valve guides... they can do simlar damage...

 

How did all the plugs look? Were any of them missing any porcelain?

 

plugs were clean no pits, except the one with a ding in the rim.

the plugs pictured are brand new as we were about to make another pass on a new set

 

I was thinking in reverse...duh... don't mind me I'm on course today and half asleep...

 

Ill post a picture of the spark plug this evening. When i saw the dent in it, that made me believe something went through because i couldn't see a chunk of aluminum from the piston making a dent in the steel spark plug.

 

BTW it is definitely not detonation buddy sorry.

 

what does the compressor wheel look like. could have also happend from scavenging. just a thought.

 

Check your valve seats.

 

I had something go through an engine of mine once. The debris only made it into #4 cylinder. I thought the engine spun a bearing to begin with as it started to knock just after I made a full 1-3 gear pull. It was knocking bad when it started too, but sounded more like a top end wristpin area knock. I pulled the plug and it was mangled. Quickly removed the head to find a small chunk of metal lodged in the combustion chamber of the head. The piston was chewed up and so was the head. I pulled the chunk out of the head with a pair of channel locks and stuck it to a magnet. To this day I have no idea where the metal came from. Where the piston was coming up and smashing the chunk of debris it was putting a lot of load on the piston in the wrong directions and put a few hairline cracks in the sleeve as well.

My turbo had one little knick in a blade and that was it. I also do not see the debris that made it into my engine going through the intercooler I was using either, but something definitely made it in there. Good luck on finding the culprit.

 

oyy

 

does 1-4 pair on the large side of the turbine housing through the exhaust manifold? if it came through the intake it wouldn't just pick 1 and 4. it seriously looks like you ate the exhaust wheel on the decel. sorry man

 

well, turbo was brand new and i absolutely never ever decel on the strip. so if low speed decel on the return road is powerful enough, maybe.

yeah 1&4
2&3