[cmitchell17]

I just pulled my heads in preparation for my cam install and noticed a pretty big scratch. I really hope I didnt do it, I have only turned the motor over a few times with a wrench to try to clean the coolant off the walls and the carbon. Problem is some of my injector seals got stuck and I couldn't get the dirt built up around the injector tips when pulling the fuel rail out and I think some fell in onto the pistons. I guess carbon isnt abrasive, since if it was, I believe all these engines would have failed. I guess there is nothing I can do now, I am just wondering how everyone else cleans theres up and keeps dirt out of it? I guess thats why your supposed to pull the motor, but I still feel like that would have been an even bigger pain.

I wouldn't think just a little dirt falling in could destroy the motor or ruin the compression, as long as I can get most of it out before I crank it up and run it. Problem is its sitting around the crevasis and it still won't come out even when I move it to top dead center and try to wipe it with a microfiber. I would try to blow the debris and dirt out but I don't have a compressor, not sure if that would even get it.

This is the only scratch I can see on cylinder #4. Not sure why it starts a half inch or so down the cylinder, but I can feel it with my fingernail so its definately deep. I remember seeing some others on here with scratches on their new LT1s from the factory.

[wwiiavfan]

You really need to have a compressor to blow debris out. Wiping with a microfiber and not blowing/vacuuming out all the fibers can wreak havoc with the oil pump. Just saw a video not long ago where a feller wiped his brand new motor out with a cloth, bolted it together, and promptly destroyed it when the fibers clogged the oil pickup.
That scratch will probably cause a little bit of blow by, but it might be tolerable.

[DorkMissile]

More than likely broken ring land. Regardless you need to tear it down

[95 imp]

Originally Posted by DorkMissile

More than likely broken ring land. Regardless you need to tear it down

+1

Dirt didn't make those scratches..

Were you supercharged?

[cmitchell17]

No basically stock besides ported intake and TB, 80k miles.

And I agree there is no way dirt did that, it was something else, but that's the only scratch I see. I have a rotofab also, but I've had 3 oil analysis done and all showed very good results with no silica traces. So I have no idea how this happend.

Is there any orientation the ring land would have so I could compare it to the location of the scratch to see if thats it?

[KingLT1]

If Dirt could cause that then engines wouldn't last more then a few thousand miles. That likely happened at the factory on initial start. Put the head back on and do a leak down test. If it passes and compression is in the same range as the other holes, then I would run it.

[cmitchell17]

Originally Posted by KingLT1

If Dirt could cause that then engines wouldn't last more then a few thousand miles. That likely happened at the factory on initial start. Put the head back on and do a leak down test. If it passes and compression is in the same range as the other holes, then I would run it.

Thanks everyone for the help I appreciate it.

And I am planning on doing a compression check to try to ensure I've got everything together right and can timing, but it probably won't be off much use since I've got to put the heads and fuel injectors back in anyway and then I've basically got half the motor on by then.

You can barely feel the scratch and it dosent run all the way down the bore and there maybe a smaller scratch to the right of it as well about a 1/8 in away.

Unfortunately I don't have the equipment and room to pull the motor, I just don't see how I could have a broken ring land with stock power.

Also I may just be being paranoid, but I'm using a razor blade to clean the heads off, but I'm not sure if I might be getting to aggressive, I don't want to get the corner of the razor cutting into the heads especially at the thin areas. I've read conflicting reports on how you are supposed to clean the heads and some say a scotch brite, I feel in some cases you could do more damage with a razor since it's a lot harder material than the softer aluminium?

Also I'm not sure how good I need to get them clean, there are traces of red gasket material in some places that I'm sure would only come clean with some abrasion with ascrotch Brite.

[6spdhyperblue]

I would not use scotch brite. All the crap is gonna get in there.

Is your ring land def intact?

[KingLT1]

They make a brush wheel that you can put on a drill that will clean it off. You need the surface perfectly clean with no residual.

[cmitchell17]

Originally Posted by 6spdhyperblue

I would not use scotch brite. All the crap is gonna get in there.

Is your ring land def intact?

How would I tell without pulling the motor and pulling the pistons?


And I do actually have the wheel brushes you put on a drill, but yes I would be worried I wouldn't have all the stuff off. I think i'm going to go buy some higher quality razor blades. Does the surface have to be perfectly clean? I also have a steam cleaner but I would worry about getting water everywhere and it rusting but I guess I could vaccum it out at the same time. I wasn't even going to worry about cleaning the carbon off the pistons since I feel like its just going to get right back on there, even though I run E85 almost 100% of the time.


Also when I took out the head bolts they were extremely hard to take out, I was scarred to use a impact drill for whatever reason so I did it by hand and now my arms and hands are killing me, but I have no idea why they would be in there so hard, is the threadform designed for interference? Also I heard you should chase the threads out before putting the new ones in and you can use your old bolts to make a chaser, I looked in the manual to see the tap size since I was just going to order one but I can't find it.

[95 imp]

King could be right with it being abnormal from the factory, or hyper could be right if you had detonation that cracked a land.

The only way to know 100 percent is to pull that slug.

Personally, I'd rather waste the time pulling it and being wrong than dumping money in it putting it back together to only wipe out the block/sleeve and have to buy everything all over again.

Sucky place to be in.....

[6spdhyperblue]

Yeah I think I would have to pull it. Even if it’s fine, I would hone all the cylinders and start fresh and get rid of the scratch. It’s not that much more to pull the motor right now. King is prob right too because I was thinking it’s super hard to crack a land on these gdi motors na...especially on E.

[oldman]

If your finger nail won't bite into it, it can be honed. If it were my engine, I'd drop the pan pull that one piston, hone it 240 is molly rings (don't know what the factory ones are??) or maybe more coarse ball and then 400 line a couple of passes to plateau the cross hatch (borrow from autozone), two new factory rod bolts. If the piston is toast, a replacement is cheap.
It is pretty easy to remove the pan and it is easier to do a cam job with removing the pan. If you are going to rev the engine past 6800 RPM, I'd change ALL the rod bolts to ARP, get the lube and get a stretch gauge. I honestly don't know if the stock rods are holed at the top for a stretch gauge, but they are heck of thin to me (lucky the stock stuff is light). IMO some holes are hard to hone in the car, that hole looks easy peasy. just tape of the others protect the crank journal and brakeleen the grit. don't stress one bore ain't bad.

[6spdhyperblue]

Not a bad option there