New World Datsuns...

Either different Piston or different Rod.

Everything looks the same, I measured all the pistons on the outside and they all appear to be exactly the same, I do not know how to measure rods.
#1 rod bearing side looks the worst and it has lines in it, #4 is the next worst, #2 just shows a little brass color, and #3 the one that came up short of the deck is the best, it barely has any brass showing, the end cap side of the bearings all look good except for #1 that has lines all the way around.
#3 definitely came up 1mm short as #2 right beside it was flush with the deck so I did not have the crank in a different position.
I could not move these pistons sideways in the bores, they are tight in there, the cross hatch markings in the bores make me think it was either rebuilt or maybe a piston was changed out in the past, if SD22 rods are the same I have extra rods, I will have to look in my parts bin although I doubt they will be the same as they are 3 main bearing cranks and my SD25 engines are 5 main bearing cranks, but I will look anyway.
#1 bearing

#2 bearing

#3 bearing

#4 bearing

Welp, I figured it out, it is the #3 rod, all the others are exactly 7.5" from where I picked to measure from in the piston to the top of the end cap(I suppose I should have measured to the center of the journal but I just wanted to know, and now I believe I do), #3 is around 1mm shorter than the rest of them, I also checked the crank the same way, they are all the same.
I have no idea if it has been this way since built at the factory or if someone changed out a rod, but they are numbered with the notch in the top of the piston towards the front, #3 says 3 on it just like the others say 1, 2, 4, so I suspect it has been that way since new.
I will look at the rods in my parts bin tomorrow.
Also I forgot to mention that the #1 rod end journal on the crank is clean(no marks/lines) unlike the bearing which has lines in it.
So far I don't see anything that I think would make it smoke the way it did, all rings are intact/not broken, maybe it was the injection pump or maybe the injectors as I never checked them, I just assumed when it overheated that it was something to do with the block/pistons/head as that is when it started.

I think SD25 pistons are only shared with the SD23(bored out SD20, while the SD22 is a stroked SD20).

SD25 and SD22 have the same stroke. It may be possible that it has a SD22 rod, especially if the SD22 and SD25 have pistons with slightly different pin heights.

I will dig thru the parts bin tomorrow and compare rods, I hope they are the same.

I think I have an issue, does this #3 rod look bent to you guys, it looks bent to me compared to the SD22 rod in the background.





The SD22 rod itself in the background of the first photo looks the same but the end cap is not the same, my scale for weighing food is not big enough as the rod maxes it out so I am going to have to buy another scale to weigh the two rods to see if they are the same weight, I just tried the SD25 rod end cap on the SD22 rod, it fits and is the same width, but it is larger round, so I don't see the point as the SD25 rods are going to be heavier.



I suppose I could use all the SD22 rods on the SD25 pistons, but I am going to have to see if I have all 4 of them.

I do not have all 4 of them pistons/rods, as I recall I sold 2 of them to a SD33 guy that needed them a while back now.
I do have a complete SD22 long block in the shed but it doesn't seem like I should tear it down as it ran before I bought it, but I will never use it either as I have a rebuilt SD22 in storage.
I also wonder about using SD22 rods in a SD25 block, it appears they will fit but I am pretty sure they are lighter as the SD25 rod has more meat as the SD25 end cap hangs out farther on the sides of the SD22 rod, the end cap is also meatier.



The rods are the same lengthwise and width at the crank, but I didn't actually try putting the SD25 piston on the SD22 rod, the SD25 bearing did fit the SD22 rod though.

There are a couple of SD25 engines for sale or part out on ebay, I will ask what they want for a set of rods and the exhaust manifold on the one.

EDIT

Well they want to sell the whole engine not parts, it would likely cost $1500.00 to get it to a Portland OR yard and then there would be forklift fees and other such fees and I would have another SD25 block around here I do not want or need, it seems like a shame to scrap this block, I should not have tore it down as it was easier to deal with complete.

Yea, that rod looks bent to me. Bent sucks but may run fine. Twisted is a different matter.

I am not going to run a bent rod in anything, and that piston comes up short of the deck also so it doesn't build up the compression it should, 1mm is a lot and the compression in that cylinder could be way down and that could be the reason it smoked so bad.
There is a forklift place in Vancouver that says they deal in Nissan parts along with all the other brands, I will go talk to them in the next few days and see if they can help me.

Yup. Looks bent to me too.

I went to the forklift place and it was not there anymore, I called the number and got someplace in Spokane WA I think, he says he needs an engine block serial number, I will go to a couple forklift places in Portland tomorrow and see if they have anything, I will also try Nissan.

I went to one forklift place and they could find a lot of expensive ones but they had nothing there to look at.
I also went to the Nissan dealer and they had trouble even finding a Nissan truck with an SD25 engine in it, they found a TD27.
I am wasting my time I think, the only way I am going to find a SD25 rod like mine is from someone parting out a SD25 engine.
I can find aftermarket rods, but they look like my SD22 rods and I have a set of them.

I put the engine back together slightly more than finger tight, I put a new oil filter on it to keep that part clean as I threw away the old filter.





I will store this SD25 block for parts, I just don't see a reason to rebuild it, and i don't want to throw it away either, SD25 parts are hard to find and they are expensive, maybe I will sell parts off of it if I don't need them.
These heavy blocks are hard to move around, I may have to make a place in the garage for it.

I have jury duty this coming week, my group was not picked for Monday, so now I have to call every evening after 5:15 to see if my group has been picked.
I did some re-arranging yesterday and today, more room in the garage again, the diesel engine has its spot, then I changed where my tire machine was and the balancer also, it gave me a spot to hide the VG30, and it's easier to access both machines.
I put covers over both vehicles in the garage after blowing the dust off them, I can almost walk completely around both vehicles now.
I have been thinking about trying to turbocharge my 520 lately if I can find that electric fuel pump the guy was talking about, I have not been to NAPA to find out if they have what I was talking about.

Got the part number?

No part number, just has to have the vent hole in the top.

I went in to jury duty today, they didn't pick me.

Of the 6 hours spent there at least 3 hours of it was spent talking about preconceived bias.

Sounds like I'd be dismissed pretty early.

It don't work that way here in Clark County, 8:15 we went thru orientation and given a number then we had to watch a video about Bias, what is was, how there was conscious and unconscious bias, and how we don't even know we practice it every day just by looking at someone and coming to a conclusion that the guy is nice or scary which is bias.
Then we went into a court room and the judge asked us questions trying to determine if we had physical/mental issues that would be an excuse to not be on the jury, then he asked about anyone knowing anyone else in the courtroom including him and staff and the prosecution and defense attorneys or the accused that was going to be on trial, then questions about molestation, stuff about what would you think or do if someone robbed you and the cops found them but they had nothing of yours on them, so that is a he said she said scenario.
It went on and on, then they started on the bias thing again, that went on and on and on and on.........................
We broke for a 2 hour lunch and we all went back into the courtroom, they called 14 people(12 for the jury with 2 alternates), and the rest of us were completely done with jury duty, that is it, I don't have to call in anymore as all them people not picked and I are done.
I would have rather just waited instead of going to lunch for 2 hours, but 6 prospective jurors wanted to express their issues with being a juror or answering one of there questions privately to the judge and attorneys instead of speaking out in front of everyone, there were over 50 of us.
There was one gal there with social anxiety, she didn't even want to talk or even answer questions, she did say into a microphone "I am freaking out", I think the bailiff pointed this issue out to the judge, I suspect that is why she was freaking out being everyone looked at her.
This time was a lot easier than the 3 times in 4 years I was picked in the 90s, as I recall I had to be there for days back then.

I've actually never been called for jury duty. I was a plaintiff in a jury trial once and had to sit through jury selection. NOBODY wanted to be there. It didn't go my way. I lost before we even started.