ap2002

iTrader: (8)

damn I just read this, sad to see the truck down again,

but like you said, it should come back stonger than before!!

7845

iTrader: (1)

what are those pistons chris make and CC? i might know someoen looking for the salvagable ones if you do go .040 over

jetmann

For those of you asking, The piston to wall clearance was .005-.0055 any looser and we will have A oil burner due to excessive piston to wall clearance and possibly A noisy engine.#7 seems to be the common problem on these engines.If the AF ratio gets to high for one reason or another this seems to be the first cylinder to take the beating.Excessive ignition timing will cause the same thing but I am sure that is not the problem here as Chris has indicated to me that he only had 17 Degrees of timing.


Rex......

Richard@WCCH

iTrader: (3)

Too much air or not enough fuel in #7. One of those two is your demon. Either which way Chris I'm sorry you have this problem especially with how nice it was running recently. Looks like a sleeve in #7 cylinder and a replacement piston and you're good to go.

BTW can you post pics of the underside of the #1 and 7 piston? I'd like to look at the heat penetrating the piston crown.

Thanx,

Richard

ZZebes

iTrader: (10)

alright call me crazy if i am but i have a theory

looking at the coolant flow circuit of an LS motor it seems to favor the Intake side of the head near the valley cover, being as though both the inlet outlet and return are on the high side of the jacket, the exhaust side is allowed to circulate and create whirlpool type currents on the exhaust side. thus creating hotspots. ESPECIALLY at 7&8 since those are dead end corners. I would love to see someone drill and tap a block next to each sleeve and measure the coolant temperature right on the sleeve as well as EGT probes, now the reason is because if you look at chris's picture the damage is to the exhaust side maybe pointing to expansion of the walls

maybe i'm nuts but i think that the cooling system is perfect for a stock displacement stock horsepower motor but the extra heat of the added hp is to much

kbracing96

iTrader: (26)

Richard,

I just when out to the garage and looked at #7 (we already put the pan back on so I couldn't see #1) and cleaned the oil off and there is almost no heat penetration (discoloration) on the under side, crown of the piston. But look at this pic again and you can clearly see the blacking of the gusseting of the skirt where it got real hot. That's the valley side of the piston BTW. This piston defiantly got real tight in the bore for some reason.

00Silv4.8

iTrader: (10)

well **** boys.. wouldnt this be a simple fix of honing the cylinder or did it expand so much that u need to bore it and get bigger equipment? This seems like its just **** on top of **** Chris, Im really sorry to hear it. I hope we get this figured out and some track time soon, my truck is all sorts of shitty running but then again at least its running.. Im sorry Chris

kbracing96

iTrader: (26)

Here is a couple pic with the oil cleaned off so you can see the discoloration.





(sorry to jump in on you thread Chris, but I was board )

thunder550

iTrader: (70)

Thanks again for the comments everyone. I'm tired of fixing problems with this thing...I just want it to run! Once again, I'm bitten in the *** by taking a shortcut. I thought about putting that Vic Jr on the motor when I first put it in but got a good deal on the SSR manifold and went that way. Every damn time I do something to save a little bit of money it kicks my *** later.

Rex & Richard - what does it take to sleeve a cylinder? I'm going to try to package up the engine here in the next day or two and get it shipped out to you.

Kyle - thanks for posting those pics.

Richard@WCCH

iTrader: (3)

Should be able to sleeve #7, put a new piston and rings in and back together. Obviously we'll need to look at the other pistons closely for any potential problems. We'll post up more after the engine arrives.

Richard