Tore my engine apart today.

S

scat

.
I was just courious to see how my 375K looked on my 98 12 valve, Well don't seem to look the best.

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All six of my intake valve keepers were pulled though.
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All of the tops of the pistons tops on the sides were coated heavy with soot, In not sure as if it was from the top ring not sealing or is common

Found 3 of the cyls with skuffing on them. I couldn't get my fingernail to catch on it
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Then the main bearings are not even wore but the rod bearings have the upper bearings are wore to the copper what isn't a supirsed at all for this many miles.

So i am planning of running main studs, updated rod bolts and a block stiffener. Pistons i have no idea on because i read and read and seems like everyone has a reason to bash the other style.
 
Never did a compression or leak down test on it. The engine ran fine when i pulled it out a few months ago. Im gonna have to do some calling around tomorrow to see who would be able to do some machine work on it.

So far for the bottem end machine work as of now:
Bore .020 over
Deck Block
Balance rotating assembly
Inspect rods for defects

Then for parts i was looking at
ARP 12mm Main studs
ARP Rod Bolts.
Block girdle: Not sure if one is really necessary with a 5K motor or what one is the best bang for your buck.
Pistons i was looking at Mahle 930036435 which are ~15.1 c/r with .150 valve reliefs

Trucks mostly a 1/4 mile truck with some grocery getter attitude:hehe:
 
Any idea what caused the cylinder scuffing? I didn't have anything like that last time my head was off my '96 at 432,000, just some small vertical scratches and some pitting in the walls. Number 5 hone marks mostly gone and #6 cylinder totally polished, no hone marks left at all...6 definitely wears the fastest. Mine is getting tired and uses a lot of oil, hope to tear into it next year, was going for 500,000 but don't think I'll wait that long.
 
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Cyl walls look normal for piston swelling in higher HP situations, you could likely hone that out but if your going with a different style piston anyway go .020 over.

Jim
 
Jim Fulmer said:
Cyl walls look normal for piston swelling in higher HP situations, you could likely hone that out but if your going with a different style piston anyway go .020 over.

Jim
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Piston swelling? I got another motor i picked up with 35K on it and the cyls all have the same marks on it. Wonder if it just wasnt honed correctly. Stock 190hp motor. I can wipe the carbon off of the pistons and they look new. I ordered the tools to get measurements on the cyls to see how close they are so ill have a better idea on what i have.
 
Basically you need to open up the PTW clearance if you're going to run higher HP. I think it looks good for almost 400k! Hell half of the engines I've seen have a solid block of soot in between the top and second ring. Are any of the rings stuck?
 
I would definitly open up Piston to wall clearance on your new engine. Im running .007" PTW and it doesnt use oil excessively.
 
JWhite said:
Basically you need to open up the PTW clearance if you're going to run higher HP. I think it looks good for almost 400k! Hell half of the engines I've seen have a solid block of soot in between the top and second ring. Are any of the rings stuck?
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None of the rings were stuck at all. I had carbon build just from the top ring up. Now ill have to call around to find someone who has a torque plate to hone this to get me moving forward again. So .0007 to.0010 PTW would be enough?
 
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