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Guys, I'm in the middle of reassembling my engine. Was hoping to have it running today but this stopped me in my tracks. There's a lip that you can catch a fingernail on, is that what I think it is?

post-71118-0-12361300-1518981413_thumb.jpg

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Correct, it's a factory machining clearance to allow access to the bolts holding the two halves together. It's tiny on an EJ20 and larger on an EJ25 (I'm talking phase 2 here, although phase 1 may be the same). It is very tight on an EJ25, I had to buy thin-wall sockets to access the bolts (I could just do it with regular sockets on an EJ20).

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I think I wasn't precise enough with what I was asking

 

See attached

I'm no expert but I'd think where it's possibly not touching the block would create a very hot spot on the sleeve.

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yeah, could be some etching issue from HG failure or electrolytic corrosion caused that?

 

I have no experience that deep into the engines so, others will have to comment on how common it is, how severe it is, etc.

 

If a straightedge across the block exhibits unevenness, I guess it needs to be decked/machined?

 

hope others chime in...

Edited by 1 Lucky Texan

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Get another block.  Confirm it first but start looking for another block if one sleeve looks different than the others.  

 

The wrist pin holes can be misaligned and the sleeve can crack too if you want further symptoms to look for.

 

What is the history of this block - this usually means a significant overheating event in the past or high boost.  Was this cylinder #4?

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I think I wasn't precise enough with what I was asking

 

See attached

 

that's not the sleeve separtating.  The sleeve doesn't extend to the top of the deck.  top of the sleeve the seem is about 2~3mm inside the bore.  The aluminum "caps" the top of the steel sleeve.  also that is an optical illusion making the piston look closer on one side.  Wouldn't hurt to mic it to make sure the bore is not out of round, but even if it was, you wouldn't be able to see it with the eye.

 

That is unfortunately pitting at the fire ring.  Based on the size of the water jacket that's a 2.2 right?  so it will use the compostie gasket which should seal fine fine.

 

If it's a 2.5, it will still probably be fine, for a while anyhow.  y real solution to "fix" it would be to disasemble the block and split it and have the decks machined.  .01mm is the limit....so that might not even take away those pits.

 

Desperate?  you could try to carefully fill and squeegie with JB weld.  Then "resurface" with a straight block and fine sandpaper.

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The lip is where the fire ring on the old gasket compressed into the aluminum. Nothing to worry about, put it back together and ride.

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The piston is shaped like a cone, and the distance from piston top edge to cylinder wall varies - the piston will rock a little if you push on it..... all that is normal.

 

The fire ring pitting is more of a concern. You can either have the block decked (requires disassembly - I wouldn't suggest it) or......

 

I have had occasion to "fix" this for a budget limited customer with a 25D,etc. They only needed it to last a year they said. I filled some pretty deep fire ring pitting with JB weld, and block sanded it.

 

That was in the neighborhood of 4 years ago and they still own the car - which is running fine. 

 

YMMV according to your skills. This is definitely NOT the right way to do it. But it has worked for me at least once.

 

GD

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Wow, lots of great info! Thanks guys, it feels great to be learning about this.

 

Based on responses in another thread I posted I already suspected ring issues, and now that I have 2 good reasons to dive into the block I suppose it’s the best thing to do.

 

I’m all about fixing it "the wrong way" if I’m the only one depending on it ;) but I don’t plan to keep this car for a long time, and I couldn’t in good faith sell it without doing it right.

 

What is the history of this block - this usually means a significant overheating event in the past or high boost.  Was this cylinder #4?

 

This is cylinder 4 on an EJ251 with a history of having its coolant passages plugged solid with buildup (heavily at #4) and being driven that way.

Edited by Dake

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it didn't occur to me that the fire ring could be confused for cylinder sleeve so the history probably doesn’t mean as much although that information given isn’t celebratory.

 

Good luck knocking that lip down.

 

Can the block halves be resurfaced as is like heads without splitting? I guess debris in the oil passages is the main issue?

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it didn't occur to me that the fire ring could be confused for cylinder sleeve so the history probably doesn’t mean as much although that information given isn’t celebratory.

 

Good luck knocking that lip down.

 

Can the block halves be resurfaced as is like heads without splitting? I guess debris in the oil passages is the main issue?

 

no.  they must be split.  

 

It's mostly so that the deck can be mounted true and parallel to the centerline of the crank.

 

debris is an issue but true location is the bigger issue.

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