Pictures..what happened to my motor

[97GsXfreak]

Alright I just tore apart my motor to rebuid it because I had low compression across the board and one cyclinder had very low compression compared to the other low ones. When I took off my oil pan I found metal shavings and gray swirly oil. All the piston rings are good so I am wondering where the metal pieces are coming from. Here are some pics that I took...are there supposed to be those flat spots on the crank like that and you can see the other damage and explain to me what happened all I know is it doesnt look good. Thanks guys

 

[GVR4592]

Can you take some more pictures of the pistons? Some nice clear shots of the top and the ring lands would be very helpful.

 

[TSIfreek]

Those skirts dont look to happy. What were the clearance on the pistons. They look like wiescos. Who built the motor??
Also those flat spots on the crank your asking about are from when the crank got balanced.
The metal pieces your finding are most likely bearing debris and is were your getting your swirly oil from (aluminum)

 

[HIGHPSI4]

How many miles on the engine? Some how the bearings are trashed. This can come from trash left in the engine that gets into the oil and is pumped to a bearing surface and starts binding to the journal. This causes faster bearing failure to the point where bearing material drops into the pan and starts getting pumped by the oil to all surfaces. Are the top of the cylinder bores 'chewed up' or clean? How do the plugs and valves look?

 

[97GsXfreak]

Thanks guys for the fast responses! I will post a lot more pics up tomorrow when I get out of work...All i know right now because it is too late to go look now is the motor was built by the previous owner apparently like 5k miles ago and he did say it had wiesco pistons in it.

 

[Defiant]

I'd guess either the bores didn't fit the pistons, or that thing had the living crap boosted out of it. Or, both. The soot on the skirts doesn't look good, and there's scraping on the cylinder walls (but I doubt that was the source of your sump paint).

 

[dsmputz]

^^^^ I'd say both too, that one cylinder looked like it leaned out and had a slight burn down.

 

[1g_tsi_awd]

Yea, it really seems like the the bores didn't fit the pistons...

And (like Defiant said as well) how much were you boosting?

 

[Maglin]

That one bearing looks like crap but it's also a crap photo. Those look like scores in the piston skirt. That would be from to tight of a piston to wall clearance which is very commonly found on Wiesco's as most machine shops don't read where to measure them at.

Also from the crank pic it looks like their is some damage to the #3 rod journal, but it is reflecting sun and it could just be the photo. If you can run a penny along the journal and not pick up any copper off the penny the journal is ok. If you can catch anything on the journal then it definitly needs to be polished at on the extreme turned.

Looking at the pistons again the one maked 2 is just nasty. Looks like metal frag's on the oil ring. Their are scores on the ring lands. I'd say it's time for new pistons and hopefully you can just do a hone on the block. You really don't want to go more than .020" over on a DD motor that will see high boost. Full drag motors are fine to go .060" over as they will be torn down more often and don't drive for longer than 10 minutes at a time. You go over .020" over and the cylinder walls start to get thin enough they don't hold as much heat and over heating issues can occur. .040" over would the on the edge of something I would run on a street car that will see up to 20 hours of continuous use.

 

[97GsXfreak]

Wow I didnt know you guys could diagnose so well with such shitty pictures Well sorry I didn't get to post more pics because the digital camara is dead and the girl friend lost the charger. Anyways so you guys think I can just hone the block and not bore it because it is already .020 over? The 2 and 3 cylinder bearings are really shot with a crack through them and the skirts of the pistons are all scored up so looks like new pistons at least. I was only boosting like 22psi. I will post up pictures of my head as soon as I get a new charger so you guys can tell me if anything happened to that

 

[Maglin]

Chances are if the pistons are scored a hone won't be enough. A machine shop can tell you about that though. You actually had cracked bearings? Sounds like it got very hot. I would guess they didn't check their bearing clearance and some where a little tight. Heat is the only thing I can think of that would crack a bearing.

 

[Enraged78]

97Gsxfreak,

Just out of curiosity, what do your ring ends look like? Are they kinda sooty like the tops of your pistons, or are they shiny, like new metal? The reason I ask is that if your rings are not gapped properly, they will butt up against each other and exand outward. If they are gapped REALLY tight, they can cause some really nasty bearing damage.

The other reason I ask is that you have scores on your combustion chamber that are not attributed to piston slap. They are running the wrong direction. This means either one of two things. Either your pistons were too big for your bores, or your rings were gapped too tight.

Thanks,
Matt.

Sump paint. Hehe. Nice one Defiant.

 

[marcell6492002]

Does you exhaust valves look the same way as the top of your pistons?