vettef6

Yes, I did.
BTW, there should be enough clearance between the piston and head. There are no marks on the head surface, and if the piston would touch the head, the marks would look different.
Piston in the hole .0015" + .036" MLS head gasket.

I will not go into answering any posts in regards to LE porting. There has been enough said, enough pictures shown and way more that I have not even mentioned.

jlpz

iTrader: (8)

since you removed the heads already why not disassemble the rotating assembly just to make sure, I know detonation can cause pitting but you said the head is not..did you do a compression test? maybe it's bearing failure, the metal pieces go through the engine and wind up on top of the piston.

Wicked94Z

iTrader: (26)

that's nothing, i should have posted pics of my pump gas piston disaster... Oil consumption WILL cause detonation though. I'd work on that problem, and stop worrying/overdramatizing

speed_demon24

iTrader: (6)

Yep its definitely not the head porters fault who broke through the ports then failed to do the proper quality control control check to make sure the ports don't have any vacuum leaks. My old LE heads had the same problem too, it's not exactly uncommon with paper thin ports and no QC.

SS RRR

iTrader: (2)

Your **** is a turd. Hush.

Wicked94Z

iTrader: (26)

wrd1972

iTrader: (12)

Maybe I have you confused with someone else. But I thought your heads were originally ported by someone else before you gave them to LE. Point being there would be great risk to porting someone elses port job. If this was the case, LE should have just declined the job.

speed_demon24

iTrader: (6)

That was the OP's head not mine.

And I wasn't aware porting heads changed the limits of where a port would break through. Not to mention a simple vacuum check that is part of the quality control procedure of any half decent head would have caught that problem before it left the shop.

Then again if I had a 13 second heads/cam/355 car I would be bitter too.

wrd1972

iTrader: (12)

Got your panties wadded up there huh.

96capricemgr

iTrader: (1)

http://forums.corvetteforum.com/c4-t...100-miles.html

Before anyone else posts a reply read that link. I simply copied it from above since some were obviously not looking at it.

As said oil in the chamber is a sure way to cause detonation. If the piston looks banged up I would be looking at the bearings too.

vettef6

Yes, reading the link would answer quite a few questions for sure.

I did remove several pistons, like it says in the link, and therefor looked at the bearings. No bearing failure, they don't look like new but no failure.
Excessive oil in the CC which in turn causes detonation was my first thought and after closing the three holes in the intake ports should hopefully solve my problem and keep my pistons from further damage.

05HD

A "sandblasted" look to the top of a piston is a sure sign that one of two things has happened.

1. The piston has been sand blasted.

2. Detonation has been occurring.

The next step is to root cause the source of the detonation issue. Oil consumption is certainly a contributor to creating a detonation issue. Were the worst affected pistons corresponding with the holes in the cylinder heads? If so it would be a reasonable conclusion that the holes LE made in the heads caused the issue. If not, you need to pursue some other possible causes (injector balance, overly aggressive tune, spark plug heat range, fuel octane and so forth).

vettef6

Like I stated several times before, I always thought that it is detonation because of excessive oil consumption. You are right, look at the picture I posted and you can see piston # 4 has way more pinholes than piston # 2. Pistons # 4 and # 5 are definitely the ones with the most pinholes. The corresponding ports had the holes, # 4 had one and # 5 had 2 holes.
So I think we have located and defined the problem. Many thanks to all that contributed ideas and suggestions. Others that posted just to increase their post #'s or made fun out of what I think was a serious question, should stay out of threads if they have nothing to contribute to solve the problem.

Lonnies Performance

iTrader: (16)

Those areas seem to be mainly in the quench area, but I noticed a small amount at the bottom side as well. Detonation can do this to some extent, but the piston looks so nice otherwise, it is hard to tell without a hi-res photo if the piston itself.

Did you rock the piston when you checked the deckheight? You typically measure at the pin area to determine compression, but for deck height, you have to rock the piston until the skirt touches the cylinder wall to see how close the piston can come to the deck. This can vary over .005 depending on the piston to wall clearance. There is a slim chance you could be too close.

Do you have any pictures of before the pistons or heads were cleaned off?
This coloration/pattern is a better indication of what was happening than a clean piston top.

Also as an FYI, the holes in your ports go to the water jacket, not to oil. Over porting makes it drink coolant not oil.

vettef6

This might be true with LS1 heads, but not with LTx heads. Follow the link in my sig. and look under "verschiedenes". You will find a few more pictures of the holes that lead into "water jackets". I say they go into oil!!!!!!

Lonnies Performance

iTrader: (16)

My mistake, I thought this picture was of your heads... I did not go to your site.


This is without a doubt, water jacket territory.


Short of the pushrod pinch area, all other porting will hit water... From looking at your site, I see you have oil leaks here.

The only other area that will not hit water is when porting into the head bolt hole a little further toward the middle of port (area between the siamesed intake ports), which should have been sleeved with a piece of steel or brass tubing to prevent going through.

vettef6

This is a picture of my head!!!

Two holes are where the bore is for the head bolts. Only cyl. # 5 is where the push rod pinch hole hit oil. So all three hit oil more or less.

SS RRR

iTrader: (2)

Actually it reads more like you were the one with a pair wadded completely up your crotch the way you burst into this thread talking **** about the OP and showing complete and blatant ignorance. You have absolutely no room to talk **** to anyone when it comes to setup failures, dear boy with the multiple page threads you've generated on how you had to be compensated for shitty work.

I would think a hole that size into water would've easily hydrolocked the engine in no time flat. Probably wouldn't of even got it started before something bent or broke.
It's pathetically inexcusable you were given a set of heads with something so obviously wrong with them. Without a doubt it's the porter's fault. Since the porter in question is indeed a sponsor of this site, you will (edit-HOPEFULLY) get this mess straightened out.

LSWHO

iTrader: (1)

That's a big F'n hole. Unless Lloyd is porting with his eyes closed with valves IN PLACE there's no excuse for that.

idformula