bought a partially rebuilt motor...How do I know if it is ready to reassemble??

[s13_240_rb20]

Ok, I bought this 93 hardbody with a KA in it that has been partially rebuilt, but I don't know to what extent. Here is what I see/know:

The valve cover and oil pan are off.The timing chain is new but has specks of rust on it (from sitting up torn apart)The water pump is new.The Fan pulley is new.Turning the crank pulley with a bar will spin the cam and timing chain (at the top) in either direction.However, it will only go about ONE turn in either direction using medium muscle-power. I haven't tried to force it on around either way.The bottom is completely assembled inside the oil pan and is covered with oil.I DO NOT KNOW if the bottom has been rebuilt or even dissassembled and reassembled because it was raining too heavy for me to take my time AND it all has a light coat of oil so I couldn't tell if there were any tool markings on the nuts.When I tried to start the motor, the starter only has a light click each time. Only once, did it ever let out a slight groan of a crank for a half-second.(YES!!! The battery is absolutely fully charged and we even used jumper cables to be absolutely sure...The battery we tried with came from my daily driver)

............................

So here I sit inside on a rainy day, waiting on a new starter to get to the local autozone tomorrow. And I ask all of you what you would think of this motor. With the new timing chaing, pulley, pump, and anything I am not seeing, I would love to get this motor running instead of pulling it and replacing.

My serious fear is that the engine is seized from sitting or there is a broken rod or something that would not let the starter spin everything. Am I being delusional on that concern, or is it possible to turn the crank about one turn both way AND STILL have bad internal problems??If it wasn't raining so badly I would go fight to squeeze my starter out so I could have autozone test it. Is it me, or is it just about impossible to lift out a starter from the hardbody engine bay???? seems like there is too much junk in the way or it would have been the rain frustrating me. Is it necessary to remove/unbolt that tedious junk in the way?

Please feel free to reply to any of my rantings/questions/concerns, especially the ones in BOLD...

Thanks,

--TJ

[Rev_D21]

You should only turn the crank one way otherwise the chain tensioner can get damaged.

[s13_240_rb20]

You should only turn the crank one way otherwise the chain tensioner can get damaged.

so I have heard from many people now, but hopefully I didn't screw anything up since I didn't forcefully turn it. Only what it would turn moderately easy for less than a full turn. I was making sure not to force it to turn over because I am so unsure that it may/maynot be seize and I didn't want to "snap" anything....

So does anyone have any ideas about how to check the "readiness" of this mystery motor?? (before I get the starter in at autozone and then crank it hoping for the best....)

--TJ

[s13_240_rb20]

Well, I got my old starter all of the way out after I slightly bent a few of the pliable metal lines out of the way. I went and had it tested and it was indeed bad. The solenoid clicked but the starter never turned.

So I slapped on the new starter (hoping for the best) and I did get one solid turn out of it, then WHAM!!! It stopped like it hit a brick wall. It feels like something is keeping the engine from turning over (making cycles)....something is stuck like a stick in the mud.

Sooooo.....do I try the "diesel in the spark plug holes" trick and hope it is just seized up ORRRRRR do I try to inspect for bent/broken rods or "melted pistons"???? If so, HOW?????

Like I said before, I don't know the history of this motor, just that it was partially rebuilt at the top. The license plate expired in 2006 so I am hoping that it has just been sitting up and seized......

What to do tomorrow when I get off work at 7a.m.??? If i get no advice, then I will go ahead with the diesel trick and continue hoping...lol

--TJ

[Rev_D21]

Sounds like valves hitting pistons.

[s13_240_rb20]

Sounds like valves hitting pistons.

lol...you have a way of replying without answering any questions or telling me anything that I can understand.

So how do I fix that, if it can be fixed??? How do I KNOW that is the issue? Is that your assumption because you know I turned it counterclockwise?

--TJ

[Rev_D21]

Well for one, I would not have put a starter motor to the engine before establishing I could turn it by wrench. The fact that it won't turn 360 degrees by hand tells me something is not mechanically timed or something is very internally wrong. Now assuming this engine has not been installed in the vehicle and the v/c and the oil pan are still off I would start by watching the timing chain, inspecting the timing marks as they go by, do they both line up? Other things to consider would be the oil pump/distributor spindle could be damaged or not installed properly, you may still have to remove the timing cover to get a good picture of what is happening. Something is binding for a fact.

If the pistons are hitting the valves then the timing chain is not on correctly and most likely everything needs to be dis-assembled for inspection now, piston tops, valves, ect. and checked for damage.

If the rods are not installed properly you should be able to detect that by watching the crank turn by hand.

At this point everything should only be turned by hand till you can establish what is causing the internals to hang up. You might have have to take the head off to inspect the pistons in motion.

How well did the previous owner know what he/she was doing? Why did they not finish the rebuild? Did they use new parts? Nissan parts? Did they use a guide for reference?

I would also suggest you get or read a Nissan truck FSM. At this point it may be better to establish what has been done to the engine that way you may be able to find where they ended or gave up. Either way you might be spending a little time with this engine to get it running. Search the KA forum for many already answered questions. Check http://www.nicoclub.com/FSM for reference material, ask an online mechanic in their forum. You have many resources here to chose from. Time to roll up your sleeves and start examining things.

Good Luck Young Jedi

[s13_240_rb20]

While keeping my eye on the chain tensioner/guide this time, I turn the crank back and forth about 1 centimeter and when it stops going forward, it sounds like a hammer taps a piece of steel. It is just a distinct dead-stop, everytime, same place.

Guess, I will just be pulling this one out and replacing it with the KA out of my other (running) hardbody. Then I can move forward with swapping my RB20 into the other hardbody (which is already set up for a 5speed).

I have diesel sitting in the sparkplug holes but unless it "unseizes" by some miracle, it will probably be pulled by the middle of next week.

Then I will have all summer to get around to taking this motor apart and possibly rebuilding as a spare.

--TJ