Supercharger and blown engine

[romin]

Originally Posted by s2d4

Even on 109 fuel? any logs?

People with issues on JRSC are starting to show up, always good to know that this is not isolated to just one type of FI or manufacturer, but our oem blocks.

I wasn't logging when the engine failed.
I do however have lots of logs from the sessions leading up to the fail.
They showed my long term fuel trims were biased negative so I was running rich.

[romin]

Originally Posted by sw20kosh

Sorry to hear! Can you describe what this oscillation? was it during throttle lift?

Thanks but at least it gives me a new project - rebuilding it stronger.

The oscillation was off throttle at 3000 RPM.
Above and below 3000 RPM it was smooth.
You could hear and feel it through the drivetrain but the source was the engine.

[romin]

Originally Posted by jsimon7777

13k track miles? Wow.

The car was only used on weekends for track driving - two years worth.
I drove it to and from the track each weekend and the rest was on the track.
The engine therefore had a very hard life - I knew something was going to give at some point and it did.
Version 2.0 will be stronger.

[romin]

Originally Posted by glamcem

Sorry to hear that

Did you get a chance to find the root cause? in the JR owners thread, you recently mentioned that some oil leakage with JR oil cooler, I wonder if it's related to that or tune (or maybe combination of both)

Root cause was a connecting rod coming loose.
Yes my oil cooler line popped off two weeks earlier and all of the oil dumped out on the ground.
The oil line was reconnected, engine was refilled, and restarted.
Everything seemed OK and I had several good track sessions leading up to the rod fail.
At this point I don't know if one event resulted in, or contributed to, the other but my lines are now clamped and I would suggest others do the same.

[Sellout]

Originally Posted by romin

Root cause was a connecting rod coming loose.
Yes my oil cooler line popped off two weeks earlier and all of the oil dumped out on the ground.
The oil line was reconnected, engine was refilled, and restarted.
Everything seemed OK and I had several good track sessions leading up to the rod fail.
At this point I don't know if one event resulted in, or contributed to, the other but my lines are now clamped and I would suggest others do the same.

Was the off-throttle oscillation present before the oil dump event?

[glamcem]

Originally Posted by D K

I dont mean to add fuel to the fire, but has anybody ever said that?

Maybe not word by word but yes many people said that over and over again, I don't make things up

[romin]

Originally Posted by Sellout

Was the off-throttle oscillation present before the oil dump event?

Yes, I spent about three months trying to track down that issue before the engine finally failed.

[Sellout]

Originally Posted by romin

Yes, I spent about three months trying to track down that issue before the engine finally failed.

Sounds like an assembly issue which may or may not have been accelerated by the oil issue.

I have a cousin that had an oem rod bolt back out in a 4G63 engine at the 80,000 mile mark after a fairly easy life on the street with a stock turbo. Could be something similar...

[sw20kosh]

Originally Posted by romin

Thanks but at least it gives me a new project - rebuilding it stronger.

The oscillation was off throttle at 3000 RPM.
Above and below 3000 RPM it was smooth.
You could hear and feel it through the drivetrain but the source was the engine.

What did this feel/sound like?

[romin]

Originally Posted by sw20kosh

What did this feel/sound like?

If felt like the engine was out of balance but only at 3000 RPM.
You could feel the oscillation all the way through the shifter as well.

Sound wise the pitch of the engine definitely changed.

The engine was smooth before installing the SC so initially I though the bypass valve wasn't working correctly given the oscillation was only present off throttle.

The other strange thing was it only seemed to happen when the engine was hot.
I first noticed it on cool down laps after a complete session.

[Poodles]

Sounds like the right RPM for a rod knock. I'll go out on a limb and say this is oil starvation related

[s2d4]

Originally Posted by vgi

@s2d4 love your answers, when someone asks 'was it' the answer is 'yes', when someone asks 'where' the answer is 'in the owners thread' (over there somewhere).
curious how happy you'd be with people answering your Qs with such informative answers.

I don't mind reading since I am not that retarded to need to be spoon fed.
It was right in the last page of the thread, which other owners never replied to.

[romin]

Originally Posted by Poodles

Sounds like the right RPM for a rod knock. I'll go out on a limb and say this is oil starvation related

I asked my tear down mechanic this question and he said there was no evidence of starvation related wear in my engine. He believes a rod cap failed.

[D K]

Originally Posted by s2d4

Yes.

I would like to see it.

Where?

Do you have a link?