pt2285

Blew my LS3 525 crate motor from Chevy. I’m never gonna buy another GM crate motor knowing what I know now.. but check out these pictures because I thought I spun a bearing and that lead to oil starvation.. but when I took it apart I saw this.. how does this happen on a motor that’s 3 months old and ran at normal op temp.

LLLosingit

iTrader: (4)

How many rpms was it turning when it let go?

pt2285

maybe 3500.

LLLosingit

iTrader: (4)

Isn't this the same engine where you had low oil pressure issues and 280+ oil temps? If that's the case I would guess that would play a large part in the failure.

pt2285

indeed it is. i had high temps on the track and i found out that my air dam was blocking the oil cooler just enough. i had low pressure @ idle only and once on the throttle i had fine pressure. i did replace the pump and it ran great and had zero issues till this. when it blew thats exactly what i thought, i threw a rod because of oil starvation. but when i opened it up i found this. if the rod came apart from the piston and went into the wall i would think it would be a more direct center hit as to the rod can only go in the direction. this hole is off to the side a bit. also i would think if the rod went into the wall it would not be so high or in an area where the piston skirt would be. im kinda dumbfounded by this.

Jontall

Those cylinder sleeves look very thin. I'd strip the block and send it to Race Engine Development for new Darton Sleeves before buying another LS3 block. Sucks.

LLLosingit

iTrader: (4)

Something gouged the wall several multiple times and knocked a hole in the sleeve, I can't see a soft aluminum piston doing that so it's either the rod or the pin, My guess it was probably the pin.

Edit: Looking again at the gouges in the first picture it definitely was the wrist pin that did the damage to the cylinder wall, As far as why the piston broke in the first place I have no idea. Probably not much of it left to do a good analysis.

pt2285

gonna try and warranty claim this. see what happens.. regardless i bought a dart 427 so this never happens again.

pt2285

exactly, i cant see why the whole thing grenaded.. and just the 1 cylinder. i dont see oil starvation doing this as to it would start at the journal over the wrist pin.

A.R. Shale Targa

iTrader: (2)

Saw this coming from your last thread
Your engine was damaged before from the high oil temps then you wrongly put a high volume pump in without having any more volume of oil Your low idle pressure was a sign. The engine was begging you to tear it down and fix it Now you have an expensive coffee table and are mad at GM. Your next engine will expire in a similar fashion unless you run a dry sump system and there’s even a pan mod for that to help scavenging for Auto cross type applications
Do your homework and listen to the experience of others

Zmg00camaross

iTrader: (11)

Previous issues with pressure and high oil temps, and Gm is at fault for mechanical failure of parts ran beyond there limits. Thinking it's someone else's fault here!

ColeGTO

iTrader: (3)

What calibration was being run in this engine? GM "crate" ECM and program, or "custom tuned"?

A.R. Shale Targa

iTrader: (2)

Here’s the thing.....rods don’t throw. Pistons rarely fall to pieces
The oil temp and follow up pressure issues wear the Babbitt off the shells. When the clearances become huge the piston is now traveling farther “north” eventually hitting the head. Hyper pistons are strong but brittle. This is when the pin pulls out the bottom and smashes the cylinder walls. You have yet to remove the rod Big end which will show you what happened here.

pt2285

The high temp issue came from an track day of running multiple laps at WOT. And like I said I found out that my front air spoiler was covering my oil cooler just enough to not direct proper airflow. My focus RS runs that high oil temp wise on the same track. It did have low oil pressure but it was still within the factory specs according to the manual that came with the engine.

pt2285

Tuned by a highly qualified and very well respected tuner in my area.

pt2285

I’m not mad, I’m disappointed I guess. I didn’t everything the book says and even GM sells this motor as a “competition” motor. Looking back and knowing what I know (which is not a lot) I would never buy another GM crate motor again. For the price there are way better options. But I followed their guidelines and the **** blew. I’m gonna try and warranty but odds are they will deny it but at least I tried. As far the dry sump, I thought about it and I went wet instead. After talking to the improved racing guys there is no reason why you can’t use a wet sump for my application. I had a quality pan, the internal baffle, windage trey, etc... I was even running a little extra oil to help prevent sucking the pan dry. I don’t know everything but I’m trying.

pt2285

See this makes sense, so odds are after my day at willow springs I prob roasted it there since that’s where I noticed the high temps prob. But even then it wasn’t for an extreme amount of time and as I said this is marketed as a competition motor. Your statement does make a lot of sense and i thank you. But my question now is why just #1 and not any of the others as to what happens to one should happen to the others evenly.

LLLosingit

iTrader: (4)

It never works that way, If you pulled all the bearing caps you're likely to find signs of oil starvation on all of them but usually one bearing will fail completely at random.

As far as oil pressure is concerned, GM's minimum pressure is also at a minimum oil viscosity, I imagine at 280* it was as thin as water.

G Atsma

I've never seen it marketed as a "competition" motor, just as a regular LS3 with an ASA cam in it. NO more, no less. If you're gonna race, at least you should make sure the engine is up to it. You had a production LS3 with a cam swap done by GM.

pt2285

Exactly, and I feel like it wasn’t.