In the idea of getting this out there and getting some insight back, I'll keep this short.

I am currently rebuilding my 300 here in school and have very limited time. Some of y'all may remember that I thought this engine was locked up, well long story short, after I unbolted the motor form the tranny it spun over like butter, but that's a post for a later date.

Back to my current situation, I brought the motor into school to look over it, the only thing with that is my instructors and making me blueprint everything out, which in the long term is a great thing to have, but I only have 2 weeks to get it back together or they are gonna tell me to pack up and move out, and I really hate that to happen while I'm in middle of a rebuild. I currently have the block completely disassembled and have learned ALOT about the engine. The engine is an 85-86 per the vin on the side of the block. When I took out the crankshaft literally all the main bearings were wiped out, major wear and discoloration. *I'll see what I can do for photos later on today. Anyways the bearings are dated to 85, so original to the block more than likely. That's pretty normal until you find out someone's been in the block and left them in there. The cylinders are a whole story on their own. The block has sleeves and the inside diameter is .030 over. Not to mention the pistons, they are kinda odd too. Aluminum .030 pistons, with factory Ford logo on them, they aren't even stamped to indicate the .030 over. I find that pretty odd, and if any of y'all have any explanation I would love the hear bout it.

On to the bad news... Cylinders #1 and #3 need machined again. I have some pitting in the walls... Not too bad I don't think. I have already ball honed the cylinders and it didn't help too much. My instructor who is pretty knowable, seems to think another .010 over will clean it up. (So, in total a .040 with sleeves and new shiny aluminum pistons? Lord, have mercy I have a race truck 😅 .) I'm looking at bout roughly $400 for machining and new pistons alone. And for a complete rebuild kit, bearings, rings and gasket kit add on another $130. So, total I can expect about $500, one hell of a Christmas gift, huh? 😅. Overall, $500 is pretty cheap for a rebuild to do it right, but not something everyone can pull out of the pocket. My thing isn't so much bout money, but time. If you remember, I'm limited to two weeks. And that's really short notice for a machine shop.

Now, for my moral dilemma, what to do? Do I bite the bullet and do it the right way and get it machined and rebuild it on my own, without help, or PMI tools from the school. Or do I risk it and slap it back together with new bearings and rings and call it good? With only needing likely .010 over, that's .005 on each side, or very minimal machine work, I can get away with running it as is. But that's not me, I like to be very through and do it the right way. I want something solid, something that will last me a long while. I'm already $6,000 deep into this truck, buying a second motor for it, having the tranny rebuilt, and maybe rebuilding the rear end myself here in school. I might as well go ahead and do it the right way right? But that doesn't really seem to play with my stack of cards, granted I could make it work. Or should I just accept my fate a let it be?

 

Do you have an engine stand at home? If so, get it machined. That said, in the early 80's, I had a '61 F100, 292, that began running badly. With the truck in my back yard, I opened it up. It had been rebuilt before and now had heavy ridges at the top of the cylinders, and the timing chain was stretched out. I bought a ridge cutter and removed them. Dropped the pan and pulled the pistons. Honed the cylinders. Put new rings on the pistons and new bearings on the rods and crank. New timing gears and chain. Drove that truck for 5 more years and moved from Tucson to northern California.
John

 

You said a second motor what happen to motor #2?
I was going to say pick up a running motor from the junk yard so the truck can be moved within the 2 weeks.
Then you can take your time with the motor in school.

Or tell the teacher you need this done before the 2-week deadline to move the truck and as you said hone, slap new bearings & rings in it and drop it back in the truck.

That is what I did to an AMC v8 motor, slapped new bearings (no cam) and rings in it so I could go racing in the 2 weeks I had between races.
The motor did really good I was shocked.
Dave ----