Heh.. This will be a long term project/thread. Just thought I'd start a thread to log my progress with this. I've never rebuilt and engine before. I've come pretty close, but I've never gotten into the bottom end of an engine before. So I'm open to tips and suggestions. Anyways..
This is the block from the original '85 B11 Sentra that I bought from an idiot (former) co-worker. It had a blown head gasket, connecting two cylinders directly to a water passage. Since adding water would have instantly hydro-locked the engine, he just ran it without water, in short spurts until it got too hot to run. (This is all speculation based on the forensic data I found within the engine). By the time I got it, he had literally driven it till NOTHING would make it start anymore. He told me it just had too small of a radiator, and needed a head gasket. Okie dokie, easy fix, looks alot like my Datsun 210, must be a fun car. So I bought it off him. It included some nice aluminum mag rims and brand new 60 series rubber all around. Oh, and he made no mention of how long he'd driven it with the blown head gasket.
After paying for it I decided to pull the plugs for a quick compression check, so I'd know which cylinders to look at when I pulled the head. The first thing I noticed was the spark plugs. They were utterly demolished. I had never seen spark plugs so utterly destroyed. It looked like someone had pounded the center electrode into the plug with a hammer, and then melted the side electrode with an arc welder. Needless to say, I discovered why it wouldn't even start anymore. I expected to find a great big hole in every piston at that point. So I did the compression check. 1 and 2 had nothing, 3 and 4 were at like 75 if I remember right.
I spent a few minutes thinking about the engine. Should I even bother pulling the head off? Should I just yank the good rims, and huck the car and cut my losses? I figured I didn't have anything better to do, so I went ahead and yanked the head off. The pistons looked fine, which really surprised me, but there was a HUGE valley connecting cylinders 1 and 2 with a water passage on the head. Eeek! Big enough I could have placed my pinky in it while the head was bolted to the block! Amazing! At this point I wanted to find that co-worker and well.. Never mind.
So I had what looked like a perfectly good block, and a head that needed to be replaced. I looked around, the junkyard wanted like $150 for a head, I could buy a rebuilt head online for $300. While I was looking on Ebay for a head, I came acrossed a whole car. But that's another story. Needless to say, I got the engine back together with the head that came on that car, after having that head rebuilt, only to find the block wasn't in as good of shape as it had pretended to be in. It smoked like mad, burned (and I think leaked) 1 quart of oil every 100 miles.
The engine ran absoutely perfect, dispite it's oil appetite. I could wind it up to 5,500 with a perfectly smooth powerband from 1,500 all the way there. Tons of torque. If I hadn't had a rear view mirror, and people weren't honking at me and flipping me off on the freeway, I'd have had no idea there was anything wrong. It didn't smoke when I started it, it didn't smoke when I left it idling for a long time and stepped on the gas, so I knew it wasn't my valve seals. It only smoked when I floored the pedal, or held the engine over 2500rpm. When I pulled the plugs out, 3 of the plugs were absolutely pristine, perfect! One of them was so oil fouled I was amazed it was still firing.
Ok, this is turning into a really long story. Anyways, I went and pulled the head back off the engine, hoping to just quickly swap in some new pistons rings, only to find some scratches in cylinder 3 (the oil burner). The scratches went up and down the cylinder on the flywheel side. They weren't deep enough to feel with a fingernail, but you could feel them with your finger. Anyways. I quickly realized simple honing wasn't the way to go, and I'd obviously need new pistons after having it bored out. So I found another block an A15, to use temporarily while I spent the time this engine would need to rebuild it.
So here we are. Rebuilding this A16. One thing I found after pulling the pistons out is that all of the rod bearings had suffered from low oil pressure at one time or another, and are pretty much toast. So I will be doing a complete and total rebuild on this engine, no half assed rebuild.
I'd like to bore this engine out as much as I can get away with while I'm at it. I'm going to take it down to the machine shop sometime this week, and ask them to inspect it, and give me some recommendations and estimates.
Comments, suggestions? Otherwise I'll just use this thread to keep people updated. Give everyone something to read when they're bored.