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Do i need to rebuild my block !!?? pic inside


Kris H

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took it apart to cange head gasket and and studs,, this is what it looks like..

 

its been running strong with no probs at all,, and was around 450hp

 

there is scrapings on the cylinder walls that i can feel with a nail

 

do i need to build a new block ?

 

thanks.

 

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Edited by Kris H (see edit history)
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haha yeah the money,, ehh is kind of an issue, but i guess i can wait til next year to get it on the road.

 

the markings in the pistons, could they be from det ore debrees in the engine ?

 

I noticed that I would of said debree by the looks of it, but could be wrong

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Detonation looks more like an erosion. This looks like you've had a lot of small chunks of metal get into the combustion chamber, and they've been hit by the squish band area of the pistons. That's the tightest gap at TDC, and as you've only got damage there, the metal debris must have been small in size. Unfortunately, these dents will cause hot spots to form under boost and start detonation when normally you wouldn't experience any. Chris Wilson would be able to advise on if the head could be recovered, I think he knows of a way to smooth those areas back out.

 

Have you ever run a HKS mushroom air filter? What's the state of your turbo fins like? Ever blown the tip off a spark plug? Finding out how the metal got in is important, you don't want to do a rebuild and have the same thing happen again.

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Having said that, I now notice you've got pitting on the piston crowns as well, that's not just carbon buildup. So could well be detonation after all. IMG_2913 shows this the most, in the top left part of the piston crown. IMG_2194 might also be showing some material on the cylinder wall, the grey bit that's not smooth? If so that's piston material sputter welded onto the cylinder wall by the detonation. The more I look the more I think it isn't a foreign object issue after all but det.

 

It still stands that the damage makes the chances of future detonation more likely.

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hhmmm,,,, the guy i got it from, has blown a set of j-spec turbos I've heard,, perhaps its debree from that ??

 

it then got a set of uk turboes and has been runing them for 2500 miles then i converted to singel last year, runing stock fuel

 

this time i'm doing fuel, clutch, and mapping to see what it will do,,

 

then i see this when doing ARP studs and head gasket :(

 

pretty gutted to say the least

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then i converted to singel last year, runing stock fuel

 

Ah. Single turbo, unmapped :( I'm guessing this is finally evidence that it's a bad idea. It'll run mega lean below 4000rpm on a single turbo, and you can be on significant boost delivering much denser air than on a single stock turbo. Textbook recipe for detonation.

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it got mapped last year running 14-15 on idle , 14 on cruise and 11-13 wot depending on load,, so dont think thats the case.

 

but will you say its time for new block, pistons and baerings ? and what about the head

 

thanks for the help

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okay i got my hands on a fresh block a set of oem pistons and full clevite bearings set,, guess there is no way around it,,

 

in a year or two i can go forged rods and pistons,,

 

but can anybody tell me if the head i salvageable??

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That really looks like impact damage to me, especially in img_2201 at the very bottom left of the picture.

 

That's what I thought, but check out 2193, top left of the piston crown. Looks eroded, and no impact damage on the rest of the crown. Maybe both? Maybe initial impact damage is causing hotspots leading to det?

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