Cylinder Wall Pitting

[blue72]

First time post here, but I can't find the answer I'm looking for elsewhere. I have searched extensively in past forums, but to no avail. I purchased a used '81 F-54 block with P-79 head last week, and when I tore into it I found something very disheartening on the cylinder wall in piston #1. I took some pictures, but they're impressively large, so I'll link to them. http://www.renderanything.com/Vehicles/Pitting01.jpg (the orange fibers are from my shop rag) and http://www.renderanything.com/Vehicles/Pitting02.jpg All of the other 5 cylinder walls look great with the original crosshatching on them, and this one appears to be fine further down in the bore. The gentleman I purchased it from has been in business with Z's many a year, but he purchased the engine from a third party having never run it himself. It apparently ran, but was pulled in a resto, and the guy lost interest. From what I could see it still had the original head gasket on it, and the coolant showed no signs of oil contamination, or vise versa, but now I'm unsure what to do. I didn't want to make this too long, but wanted to explore my options. I know it'd be foolhardy to try and use it as is, but I was wondering what might have caused this? Metallurgy?? Detonation? As is I will probably have it bored .1 over, get new slugs, and reuse the rest of the good stuff on it. My hope is that something like this won't happen again further down the line though. Let me know your opinions, and if you've ever seen this on a L series block before.

[Tony D]

Save some money, chances are all your pistons are good, SLEEVE the offending bore, and have the others honed/deglazed to standard spec and put new rings in and be done with it.

 

This is why Nissan Showed Liners for the block available...to repair one cylinder to standard instead of following the American Standard of overboring everything and tossing all the pistons at the same time.

 

Sleeve shouldn't be more than the cost of boring all six, and that saves you the cost of the pistons!

 

I'm assuming you can feel this when you drag a fingernail over it...

[blue72]

Yeah, you can feel the missing bits of the wall with a fingernail, in fact, you could file your nails down with it. I like the idea of a sleeve, but would I need to order that from Nissan, or would a reputable machine shop have the capability to make one for it? Thanks for the idea. I'm planning on pulling the block back out this weekend, and dissasembling it, then I'll know if the #1 piston is still salvageable.

[Tony D]

Any competent machine shop should be able to make a liner, or simply order one in. Darton Sleeves, LA Sleeve, there is a bunch of people making drop-in sleeves for service repairs.