Deep gouge in cylinder wall (Page 1/2)
katie80 AUG 17, 12:32 AM
A couple months ago, I decided to rebuild my engine (2.5L). I've had this car since I was a teenager so never really considered that it needed to be rebuilt (I think it really did need it, in hindsight.) I got the head off and found, in one cylinder, there is a really deep gouge. I have never seen anything like this.

Here is a photo of cylinder 3:



Here is a photo of cylinder 2:



I would like some suggestions of what to do. I've almost had enough of this car, and it was never really worth fixing, so I don't want to replace the engine or the block. I want suggestions that I could possibly do with my current situation.
katie80 AUG 17, 12:35 AM
sorry, those image links are broken. can't figure out how to upload these photos straight to the site on my phone.

here is a Google photos link:
https://photos.app.goo.gl/D4Kbr743KBK75asN8
Patrick AUG 17, 01:18 AM

quote
Originally posted by katie80:

...I don't want to replace the engine or the block. I want suggestions that I could possibly do with my current situation.



IMO, your only option then is too have this block bored out enough to get rid of the "gouge". Every cylinder would need to be done, and oversize pistons would be required.
[EDIT] I suppose if the other three cylinders were perfect, this one cylinder could be sleeved, but I honestly don't know how common (or cost effective) that practice would be with a 2.5 duke.

No other way to put it... this looks bad. Was this engine burning oil?

[This message has been edited by Patrick (edited 08-17-2024).]

jelly2m8 AUG 17, 03:16 AM
To be fair, it looks like an engine sat for a number of years and that's where the rings sat. Me? I'd pull the piston and hone it and then see what the bore looks like.

It's a 2.5, it's not a high performance engine, it does not have to be factory perfect.

[This message has been edited by jelly2m8 (edited 08-17-2024).]

Patrick AUG 17, 03:34 AM

quote
Originally posted by jelly2m8:

To be fair, it looks like an engine sat for a number of years and that's where the rings sat.



...along with water sitting on the piston in the cylinder, judging from the pitting in the cylinder wall. It's difficult to tell in the image how deep that "gouge" is. IMO, cleaning it up completely would require boring it out to at least 0.010" over... but it's pretty difficult for any of us to tell from an online image.
katie80 AUG 17, 05:26 AM

quote
Originally posted by Patrick:

IMO, your only option then is too have this block bored out enough to get rid of the "gouge". Every cylinder would need to be done, and oversize pistons would be required.
[EDIT] I suppose if the other three cylinders were perfect, this one cylinder could be sleeved, but I honestly don't know how common (or cost effective) that practice would be with a 2.5 duke.

No other way to put it... this looks bad. Was this engine burning oil?






I was thinking the same.

the other three cylinders are in shockingly good condition, I haven't measured them yet, but I will.

i can't find any info on sleeving a duke online though... definitely is a bad situation.

the engine was burning oil, it was probably about a quart in a month when i was driving it regularly (maybe like 1500 miles in a month). it did also have some leaks. definitely had a good amount of blow-by as well. the air filter was coated in a bit of oil most of the time from the breather.
katie80 AUG 17, 05:31 AM

quote
Originally posted by jelly2m8:

To be fair, it looks like an engine sat for a number of years and that's where the rings sat. Me? I'd pull the piston and hone it and then see what the bore looks like.

It's a 2.5, it's not a high performance engine, it does not have to be factory perfect.




I was also thinking this. the engine ran well enough for me to put 15,000 miles on it before it constantly had a misfire.

When I bought it, it had been sitting since 2006, I bought it in 2021. The guy who I bought it from had gotten it running, I assume without checking anything beforehand. I'm not even sure he changed the oil before he sold it to me.

i really just want to be able to drive it a little longer before I sell it for parts (it's too rusty to be worth restoring or anything like that.)
katie80 AUG 17, 05:35 AM

quote
Originally posted by Patrick:

...along with water sitting on the piston in the cylinder, judging from the pitting in the cylinder wall. It's difficult to tell in the image how deep that "gouge" is. IMO, cleaning it up completely would require boring it out to at least 0.010" over... but it's pretty difficult for any of us to tell from an online image.



the water in the photo is likely just coolant from when I took the head off. it wasn't a super clean process. it ran on all four cylinders at one point in my ownership.

I'm not really sure how else to describe the defect, it's much deeper than anything I've seen. it's not the kind of thing you could miss running your fingertip along the wall.
PhatMax AUG 17, 07:52 AM
Sleeving is not that big a deal. But might be able to get a short block cheaper than the rebuild.
82-T/A [At Work] AUG 17, 10:13 AM
When you rebuild a motor, you generally want to have the cyl walls bored to an extent, along with new pistons anyway, so it's not really a huge problem anyway.

I think in this case, you're probably looking at the maximum cyl bore of probably a .060 overbore. You can buy Duke .060 pistons on Rock Auto pretty inexpensively.


Worst case, you have to sleeve it. Machine shop costs would normally run you about $500 for a hone / bore. If you have to resleeve it, that's probably another $300. This is just what machine work costs. You would want to do the rest. You can definitely do this.