Well no idea how it ran. I pulled it from this salvage 1981 210 wagon. I had no intentions of getting another A15 motor while I was looking for a 5 speed 60 series transmission but what caught my interest was the oil filler cap. Is this a JDM motor? I popped the valve cover off and it had the rare H89 head (single spring). So took it home. A problem I see with this motor is that the water pump was seized with alot of crud. And when I went to take the head off, one of the bolts (#1) was very difficult to remove. Finally worked it loose. The bolt also had some crud on it. Likely overheated and maybe caused damage? The head surface is flat and dont see any signs of a cracked or damaged head. The motor turns freely and the crank has less end play than my other A15 motor so I plan to go through it and give it a refresh. Still can see the original cross hatches. I will be taking it to a machine shop to get it cleaned with a good detergent (no harsh chemicals) and they will spec out the bore for me. If its good, I will have them hone it out. Its a toss up to go with either the GX head or H89 head but will likely stay with the GX head for this build.

If this is a JDM motor any idea how it ended up in North Texas??

Attach file:

---

  1981.210.jpg (38.07 KB)


  oil.filler.cap.jpg (17.33 KB)


  h891.head.jpg (20.14 KB)

It's normal. Did the engine have any audible bearing tapping? If so it warrants extra checking. But if the engine was quiet, well remember the bearings can go 500,000 miles so no worries. They are big bearings and made of super-strong material. Most bearing failures are the result of lubrication problems either running out of oil, old oil, or contaminants getting in the oil, and not from old age

Ok understand DD. The bearing clearance specs is what I compare to the plastigauge results. So how about the side to side play on the piston rods? It's not much but noticeable. Is that normal?

Bearing crush is only used when installing new bearings.


To examine used bearings, measure the clearance using the plastigauge. If the measured clearance is within the spec range, they are good. Too much clearance and the oil pressure drops. Too little clearance and they could bind.

Datsun Factory Service Manual (see Bearings)


Also give them a quick visible inspection. No scoring, no pits, no scratches, no heat marks ... they can be reused

Some shade-tree mechanics don't want to use plastigauge -- in that case they measure the journals and bearings directly using micrometers then subtract the difference to get the clearance. Or if you are checking a crank that is not in the engine, you can measure it directly. Otherwise you can ignore the measurement specs and only use the clearance figures.

Plan to pick up some plastigage this afternoon and disassemble the crankshaft. Reading the information in Tech Wiki, the "bearing crush" tolerances is what I will use to determine if the bearings are within specs? And reading the Haynes shop manual the tolerances for end play is only at the thrust (center) bearing? Please explain the "bearing clearance" tolerances. Also I notice a slight lateral movement in both directions on all of the connecting rods, but not up and down. Is this normal? Engine has about 130K miles. Thanks for the help.

Bearing Clearance
* Main: 0.020 to 0.062 mm
* Rod: 0.020 to 0.050 mm
Main Bearing Journal diameter
* 49.951 to 49.964 mm
Crankpin Journal diameter
* 44.974 to 44.961 mm
Journal Taper and out of round
* measure multiple spots
* less than 0.03 mm
End-play
* crank thrust: 0.05 to 0.15 mm
Bearing Crush
* main: 0 to 0.03 mm
* rod: 0.015 to 0.040 mm