Rawze.com: Rawze's ISX Technical Discussion and more

(12-26-2019 )tree98 Wrote: [ -> ]I'm very interested to find out too. Are those scores on number 2 piston above the top ring? Does the liner look like that too?

The scores are in the carbon - there's some scoring on the intake and exhaust sides, but I can't even see the marks I pictured from below a couple days ago.

The exhaust side of the liners seem to be the worst. It makes sense why sometimes it seemed to have less blowby - things would seal for a while and then a chunk of carbon would ruin the parade.

Maybe injector spray pattern isn't right? The fuel is getting dumped in rather than sprayed in ?

(12-26-2019 )tree98 Wrote: [ -> ]Maybe injector spray pattern isn't right? The fuel is getting dumped in rather than sprayed in ?

I'd tend to agree if it was just one cylinder, but from what I can see, it's all of them, #2 just was just the first suspect until I got the head off. I replaced injector #6 in May'ish, and then the other 5 in August.

You using any kind of fuel additive?

(12-26-2019 )tree98 Wrote: [ -> ]You using any kind of fuel additive?

Not regularly, but I have used Amsoil All in One. Truck usually runs like crap with any cetane booster though.

Which came first, chicken or the egg?

Ring gaaaaaap.



Top ring, .015"
2nd, .069"
Oil, .010"

Strange chatter looking marks on wrist pin?



Con rod bushing looks good.

I'd really like to get input from Hagg and Rawze, but I'm leaning towards the ill-received statement from Rawze way back. It felt like a punch in the gut then, even more so now haha.

(09-02-2018 )Rawze Wrote: [ -> ]I don't care how pretty you made the outside of it,.. Any after-market crap inside the engine is a no go in my book.

http://rawze.com/forums/showthread.php?t...4#pid30004

(12-26-2019 )Nostalgic Wrote: [ -> ]Top ring, .015"
2nd, .069"
Oil, .010"

here is the official spec...
[attachment=5990]

this pic ...

http://www.dunbarchrome.com/image/jcMG

It looks just like too much injection timing for the build. - That or too much air.

I looked at the program(s) you are running (at least the ones you have sent me).. and it is running roughly in the +1 to +3 btdc SOI mappings at higher torque, very conservative, and no offset. - I do however have an early program you sent me where boost was much higher and someone added a few degrees SOI,... but it is nowhere near outside of the safe zones for that thing to say it could have caused any harm that quickly.

Makes me wonder if the compression ratio of those pistons is higher than normal. a lot of that looks just like when a 2350 gets more than about 2 or 3 degrees on it at high torque.

Maybe timing actuator going bad? -- It is more significant on the front bank than the back, but all of them seem to have the issue.

it is strange, and rare, to see that on an ISX where the injection timing, and other things are set properly, unless at some point in its past someone was trying out some wacky settings perhaps, and it happened all at once, then took its toll later on?.

Only other thing i can think of is maybe the piston temps were higher than normal and it was making for fuel condensation during mixing?

Unsure -- (Rawze scratches his head).

It looks like impingement due to too much fuel mixing time in the cylinders for the compression ratio, etc. according to that pic -- unless I am missing something.

maybe excessive cetane booster addatives?

Even so, I don't think it would have scuffed a liner like shown in your first pics. That is something else, as high carbon packing usually leaves behind vertical streaks as it flakes off and gets into the rings.

Was the engine really tight to turn by hand before tearing it down?

Just some thought.

In any event, keep one of those pistons. i would like to compare it to an OE piston and see if there is something that would change the compression ratio, etc. on it if you can. - maybe send it to me so I can have it here as future reference?