numbers matching engine, is it important?
 

So, I need to rebuild my engine. I have two complete P30 blocks, my original numbers matching block, and a donor block. The original P30 has a spun rod bearing, which ruined the crankshaft. The donor block is in my Z right now, but burns oil pretty badly. In the sake of making numbers match, would it be possible to swap the crank and rods from the donor block and put them into the original block, since the original crank is damaged? I figure that doing it this way would make it so that the value of the Z would theoretically be more due to numbers matching.

Also, the original P30 has been sitting in my garage for close to two years, and has a slight bit of surface rust on the cylinder walls. I tried to wipe it off with some WD-40 on a cloth and buffed it dry, but it didn't seem to make a difference. Here's a pic of how it looks:


By the way, sorry about the quality of the pic, I only have my cell phone camera.

You can swap the crank and rods over to the original block. But it might not be a drop in job. You'll still want to check clearances and get the proper size bearings.

it is not imoprtant for the crank to match, as long as it is from a same casting # block, then it should all match up, but measure first and be sure, this would prolly be best for the machine shop. as for the cylinder walls, a basic honing is all you will require. # matching motors basically only refers to the external block and head, and sometimes the intake manifold. you can do whatever you want to the internals, like bore it out, cam new rods, high comp pistons, etc.

Yeah, I understood that. So, the crank and rods are ok to swap, as long as the crank hasn't been ground out for larger bearings, right? I just have two blocks, and I was thinking about getting the numbers to match.

I wouldn't just drop the crank on the old bushings though. No sense in half-assing it. Get the crank checked out and install it with the correct size, new bearings. Same goes for the rods. It's the least you can do if you're going to have the motor apart anyways. And then you'll have a fresh motor.

If you HAVE to re-use the old bearings make sure they are the bearings from the engine the crank came out of. But I wouldn't recommend using the old bearings at all. I personally would never even consider it.

I agree totally. When I get the engine rebuilt, I'm going the whole nine yards. I'm renewing the bearings and rings, just keeping the crank, rods, and pistons.

then you sir are golden :048:

alright then! I guess I'm on the right track. Now it's all about money and timing.