06 ram cylinder scoring HELP!

[Johnny1]

Hey guys, straight up, i keep blowing head gaskets and scoring the cylinder walls. the scoring is minute enough that i can hone it out. this has happened twice.. Ring gap??? its .020 over.

WHAT is the correct ring gap for all three rings, for a 900hp truck... :umno:

 

[ComnRailPwr]

I don't have my spec sheet in front of me but I would suspect PTW clearance to be the issue. As far as head gasket goes, what head studs do you have? properly finished surfaces, Some 625's and a stock meals gasket will hold those power levels about problems.

 

[Johnny1]

I have 625s Mls gakset And low ra finish ! I have my top gap at .022 the engine is only 3k old !!

 

[Blueboy]

I am waiting for someone in the know to answer this, I was told by Tim Barber
.025.

 

[fatgraderman]

What did the skirts on the pistons look like? What was your timing up to?

 

[Bponci]

Whats your ptw measurement? Where is the scoring showing on the piston. Pics may help some too.

 

[huhta99]

was the block deck plated when it was bored

 

[Johnny1]

i will post specs tomorrow with pix. block was not deck plated, scoring is more in the center of the bore, mid stroke.

 

[Johnny1]

timing 30 degrees

 

[mike diesel]

When I did my duramax motor, mahle recommended .004" per inch of bore for ring gap.

 

[Dman1198]

The ring gap spec I got from a 96 manual had the top ring from 16-26 thou

 

[EricStaab]

Ring gap on stock bore .024-.025

 

[Johnny1]

how about ring gap for 20 thou+ bore?

 

[Johnny1]

When I did my duramax motor, mahle recommended .004" per inch of bore for ring gap.

aight, will investigate

 

[BanjoDiesel]

Very curious as well to what the gaps should be for all the rings on a .020 piston..

 

[Johnny1]

Look. so the scoring is more like scuffing. It seems the gasket failed between cylinder # 2 and 3 some what. Also it burned all the ceramic coating off! is that what some of the block stuff around the edges is?

 

[Johnny1]

look at the heat between the cylinders, and on the last pic there is a white spot on the edge. any ideas??????

 

[fatgraderman]

I'm not sure what to think of the coating. That's a bit disappointing. Looking at the spray patterns on the pistons, maybe timing was a hair aggressive and that helped do in the head gasket, but I'd be just guessing. I just haven't messed around with anything max effort. I might be tempted to send some of those injectors off to an injection shop for testing. That's all disappointing for 3000 miles. :banghead:

 

[12vriviera]

Are those pistons tapered at the crown at all?
and what is pts clearances?

 

[D&J Precision]

Looks like dirt to me. One of them looks like the top ring has lost tension from over heating. As for the coating we have seen that a lot in the diesels that is why we do not push the coatings. That could be where your scoring is coming from too as it flakes off. How is blow by?