Im thinking about buying a B20 block, it looks fine from the outside, but what about the inside? How can you tell the blocks condition without opening it up? I just dont want to put money into something that has bad piston rings or something.

 

The only thing I know to tell you is get a wrench and rotate the crank, if it turns smoothly it is safe to say the pistons and rods are okay. As far as the rings I dont know how you could check them, hopefully someone with more knowlede about this than I will see your post and respond. Hope this helps!

 

Thank you very much, it does help. Does anyone else have anything else?

 

Be pro-active as opposed to reactive if funds permit. It's more re-assuring knowing that you replaced the rings (pistons will have to come out), than not knowing if they will go soon. Block can be taken to a machine shop where it will be hot tanked and visually inspected for cracks. This is the only manner to determine if the block is usable. More advanced methods exist, such as using dye to inspect for cracks.

Determing the condition of piston rings is difficult without actually removing the piston/rod assembly. If this is done, it makes sense to go ahead and replace the rings. Better safe than sorry in the long run.

 

Do a compression check if possible, if its good , the motor is most likely good.