I have a engine that has sat in the box forever and seems to be seized up. What should I do to get it rolling? Thanks!

Soak it in a solvent, like glow fuel over night and see if it breaks free. If it doesn't soak it longer. Then check it for rust by removing the backplate, if there is any present disassemble abd replace the bearings. Where can you get the bearings, Boca Bearing!
will

You can also simmer (on low) in a crockpot of antifreeze. This works great. You can take the engine apart first, which helps, but at least try to get the head and backplate off.

Obviously, don't ever use the crokpot for food again.

Like it would change the taste of my moms nasty food. j/k my mom has great food but keep her away from the frozen fish sticks.[:'(][:'(]

You can also go and get some denatured alcohol ($2) and then soak the engine.

I know and older gent, that has umpteen millions of motors stored away,that swears by mavel mystery oil.

You could also stick it in a dish washer on hot and
let it wash. I havent needed to do this but i know of
a couple of guys that has done it and claimed it worked
fine. I would oil it up real good after wards.

So soaking it in glow fuel for 1.5 days and then putting it in the dishwasher seems to have loosened things up. So I put some 10w30 engine oil in it but I think that was a mistake. I was just trying to get it lubricated. It seems to be gumming up just a little bit. Ideas now? what kind of oil should I have used? Thanks for the help and sorry for the rather stupid questions...

Airtool oil works really well.

Personally, I use Automatic Transmission Fluid (ATF) oil for after run oil.

When rebuilding engines, I usually use 3-in-1 during assembly, it's a little thicker than the ATF, so it coats well and allows things to slide together, but it can become gummy. ATF doesn't gum up, and protects against rust rather well.

Lots of good options out there, but automotive engine oil is a bit too thick, I think. (I also think it will burn off at a lower temp, and make a mess when it does, but I haven't tried it, so I'm guessing on that count)

Diesel fuel works great for soaking frozen items in to free them.

Coca-cola!

I am not kidding. My brother introduced me to that one. A differential from a 57 Willy's TJ5 Jeep. Seized and rusty. Coke for a day, spray with a hose-pipe, and it was turning again. Gritty, but turning. If I hadn't seen it done, I would have never believed it.

gus

OK, I think from the replies just about any kind of liquid will work. I'm thinking the toilet for a couple days and keeping using as normal might even work. The agitation and acid might even help. Can't be worse than the dishwasher or coke.

Seriously, there might be some seels in there that would be ruined by some of these processes. Most likely there's something in there that isn't metal. The engine runs on glow fuel so I'd guess that would be the safest to soak it in.

you did take the glow plug out right???and what engine is it? is it sleeved..?big difference between an old cox .049 and a 10 year old OS .40FP.......so what ya got ?