how to check if motor is in good shape?

[Importroller]

I should be picking up a S13 soon, with the motor already out of the car. The person selling it said they rebuilt the motor with new pistons and rings. Is there a way I can check how good the motor is internally without it being installed in the car before i buy it?

[Thee 240sx Owner]

Compression check is the first thing to check seals.. pistion rings... timing.... Also.. check timing to see if motor is timed .... standard stuff... remove sparkplugs and check for oil or if they are very white... ps pump, altenator and what not are simple... oil, transmission fluid... typical stuff.. but compression testing is the best to do... and white smoke when you start it or while reving

[Importroller]

i know how to test it with the motor installed, but this motor isnt currently installed. So thats what i need to know. i need to know how to test it without it being installed

[fiznat]

He said the motor isnt in the car... so I think you're gonna have a little bit of trouble checking timing, smoke, etc...

I BELEIVE you can still check compression by cranking the engine by hand, but I dont think you're going to get completely accurate numbers.

I would just ask for receipts from the rebuild, ask where he got it and the exact specs on the engine. Call the place where he got the work done and ask them what they did, and how long ago. Find out what parts were replaced and what ones werent. You should pretty much be able to tell by looking at the engine which parts are new (except internals of course...) If the engine is pretty much NEW (as in fresh out of the shop), I would ask the shop if they still have a startup warranty on the engine at all...

I donno man its a tough thing to do, but I think receipts and word from the actual machine shop are going to be your mest methods of checking this motor out.

[Thee 240sx Owner]

ya sorry all i read was that title.. i'm in a post whoring mood.. ya i really can't help you there at all either man.. all 4 of my motors i purchased were out of running cars i saw.. i would go with what fizzy for shizzy said

[Dattebayo]

You can hook the starter up to a 12V source (like another battery) and check the compression while you crank the motor out of the car. I'll get the compression #'s for U later.Do not crank the motor for more than 10 sec. ata time.

[Importroller]

i know how to check compression, ill bring my gauge with me. I didnt know if it would work with the motor not in the car, and no oil in the crank case though