Oh fun! Spun rod bearings!

**Tachyon** · 10-09-2009

Man... I am not having a good week...

I just finished building another 2.4:

Everything was cleaned and machined to my specifications by Gosh.
Crank was balanced and polished.
Custom pistons had the PWC I wanted.
I ground the rings for my usual end gap.
Valve clearance was clayed and several thousands better than I required.
Correct clearances (plastiguage) for main and rod bearings, correct side clearances (feeler guage).
Graphite Moly used on the bearing surfaces, 20w 50 dino on the rest.
PermaTorque headgasket with A1 studs torque to 100lbs with moly in 6 stages.
OEM 2.4 cam gears (no degreeing required) and timing belt, alignment and tensioner gap was correct after spinning, waiting a hour and respinning.
Primed oil pump with grease.
Everything spun nice and smooth.
Filled the engine with straight 30w dino oil for break-in.

Fired the car up, verified oil flow at the head.
Let car warm up to 200 degrees.

Took it out and began to break in the rings. I was taking it up to ~12 psi, at 4 to 5000 RPM and then engine breaking in a low gear. Car felt really strong. After about 5 minutes of this I was approaching a T intersection and popped the clutch in and proceeded to coast the last 200 feet. It was at this point that the unmistakeable sound of rod knock started. Very quietly at first but rapidly increased in noise when suddenly I heard a sick metallic screech and the motor seized. Thick black smoke was everywhere, pouring out of the head evac.

Flash forward to last night. I removed the oil pan to get a better look. Behold the carnage:

Look at the heat discoloration!

The crank is just FUBAR...

This is the shot that really scares me, because it appears that for some reason the bearing was not getting oil. looking up the journal it appears to be dry.

I've only built a handful of 4G engines, so I am most certiantly not an expert. Still, does this seem rather odd? I am trying to figure out what I did wrong on this engine or if it was a clogged oil journal in the crank or block?

Anybody have a similar situation with a freshly rebuilt engine?

**scheides** · 10-09-2009

Wow, week of carnage. Sorry dude

Thanks for the awesome pics though, hopefully you get to the root of the problem!

Matt D. · 10-09-2009

Did you prime the engine before starting it?

Super Bleeder!! · 10-09-2009

Wow, it seems like you knew what you were doing. I suppose you should pop the freeze plugs out of the oil galleys and take a look.

Also perhaps the oil galleys in the crank itself are clogged.

**asshanson** · 10-09-2009

Are they all spun or just that one? Definitely looks oil starved, very dry in the crank by the looks of it.

**Tachyon** · 10-09-2009

Quote:

Originally Posted by Matt D.

Did you prime the engine before starting it?

I turned it by hand a few times, but did have quite a bit of lube in the oil pump housing. The funny thing is there was oil flow to the head, which is the last place the oil visits before returning to the pan.

I think I'll have to inspect the crank journals before installing the next crank. Live and learn I guess...

Asshanson, I've not yet verified if more than one spun. You can see oil coming out of 2 of the other rod bearings, but nothing on 4. If both 2 and 4 spun it really makes no sense because the oil galleries I believe are different to both bearings.

**Tachyon** · 10-09-2009

Ok, here is the oil diagram for the 2.0, which should be the same as the 2.4, 6-bolt.

If this is correct, the the problem almost has to exclusively lie in the crank since at least two of the rods were getting oil, the mains are fine and there is oil to the head. I guess the next step is yank it all out (again) and inspect everything.

Kevin 1G Drummer · 10-09-2009

Wow, that sucks. My guess is that the oil galley in the crank was plugged up, Thus,m starving that bearing of oil.

blackrosenova400 · 10-09-2009

You should call me, I work in Savage, Id like to come see if after I get off of work at midnight.

612-221-0778

Chad

blackrosenova400 · 10-09-2009

I hate to break it to ya but that indicates a misinstalled main bearing. Let us know what you make of it!

**Tachyon** · 10-09-2009

Quote:

Originally Posted by blackrosenova400

I hate to break it to ya but that indicates a misinstalled main bearing. Let us know what you make of it!

Ok, that's exactly the info I was looking for. I left you a voicemail. Give me a jingle when you have a moment.

Thanks!

Ronnie S · 10-09-2009

Main bearing switched between block side and main cap? The bearing on the block side has the oil hole. The main cap doesn't. So that makes sense.
Man that sucks. I've seen some cranks come back from being polished with carbon stuck in the galleys. The first thing I do is blow them all out be almost always find some.
Blackrose seems to have it right thou.

blackrosenova400 · 10-10-2009

http://www.aclperformance.com.au/us/...bearingsus.htm

There ya go, you can see which bearings are supposed to be up in the block and which ones should be in the cap. You accidently had a couple mixed up. The caps you pulled that we looked at, the grooved bearings should have been in the block.

What are you gonna do next?

adidasdudegst · 10-11-2009

Man, that really sucks, sorry to hear that. What a pain in the ass. At least you found what was wrong... I spun a rod bearing about a year ago on my GTP and was lucky enough to find someone to still buy it... Maybe it was a good thing it happened, cause now I have my Eclipse...

... good luck with the fixing

sleepydsm · 10-11-2009

This is a bad week.... Sorry to hear! Are you gonna build another motor?

**Tachyon** · 10-11-2009

Quote:

Originally Posted by blackrosenova400

http://www.aclperformance.com.au/us/...bearingsus.htm

There ya go, you can see which bearings are supposed to be up in the block and which ones should be in the cap. You accidently had a couple mixed up. The caps you pulled that we looked at, the grooved bearings should have been in the block.

What are you gonna do next?

Yup. I referenced that when you left. I feel really fucking stupid right now...

Quote:

Originally Posted by sleepydsm

This is a bad week.... Sorry to hear! Are you gonna build another motor?

You're damn straight I am. I am debating if I should try and get it done for the cruise... I have another 2.4 6-bolt crank and some spare bearings. I probably could do it, but I am rather gunshy right now.

**4seasons69** · 10-11-2009

Quote:

Originally Posted by Tachyon

Yup. I referenced that when you left. I feel really fucking stupid right now...

You're damn straight I am. I am debating if I should try and get it done for the cruise... I have another 2.4 6-bolt crank and some spare bearings. I probably could do it, but I am rather gunshy right now.

man that sucks big time! at least you figured out why it spun. I say go for it since you figured out why it happend. just cause you fall off a horse doesn't mean you shouldn't get back on

blackrosenova400 · 10-11-2009

Meh we all make mistakes.

Quote:

Originally Posted by Tachyon

Yup. I referenced that when you left. I feel really fucking stupid right now...

You're damn straight I am. I am debating if I should try and get it done for the cruise... I have another 2.4 6-bolt crank and some spare bearings. I probably could do it, but I am rather gunshy right now.

**mlomker** · 10-11-2009

Education is always expensive, regardless of the field that you are in. I'm kicking myself for buying 800cc injectors because now I want to go E85. That's life and it doesn't end until you do.

There isn't enough time to know everything, so eventually you accept human limitations and strive to be the best at what you specialize in. The rich are people that specialized in something valuable and the poor are people that didn't have a plan.

Nothing wrong with wasting money on hobbies, if you are conscious that that is what you are doing.

Mike Neal! · 10-11-2009

Damn, Sorry to hear that.. I wish I got off that lucky tho.. lol followed by sad face..