Been seeing ads and websites for rebuilt/remanufactured engines. And I want to know more about them.

Are these complete engines?
Do they run well?
Do they break in a week?
Why are they a sixth of the price of a crate engine?
Should I consider getting one?

Thanks!

 

Rebuilds are what they are. A cheap way to get running again after a catastrophic failure. Are they of the same quality as a crate motor, no.

Are they complete? read the fine print. Some are short blocks, some long blocks, some complete. Depends on the way you order it.

Why are they less? Crate engines from the factory are made with new parts. rebuilds are made with reconditioned used parts. Sometimes a seasoned reconditioned part is as good as a new part(Resized, polished connecting rods for instance)

Break in is the same as any motor. More damage can be done in the first 20 minutes than the next 30,000 miles. Most of the motors should be pre-tested. They will come with break in instructions (or should)

For them to make money on a rebuilt they have to do the least amount of work and still have a useable product. They may turn the crank to.030 instead of replacing it, sure it will still work under normal driving conditions, but I'd be carreful about modifying it too far. Also, did they bore the block past .060 and use oversize pistons so they didn't have to scrap it? Do the head castings match? Are the valve springs stock, cheaper than stock? better than stock? new valves? reconditioned? Who does the machinework and are they any good?

I'd look at local machine shops and get a price on rebuilding what you have. At least then if something goes wrong I can deal with it locally. Or buy a rebuild kit and get the machine work done locally.

All that said, there are good rebuilds. If you find a mail order shop with a good reputation, go for it. I do have a couple mail order motor suppliers I use for the race engines and I love them. I've never had a problem with one of their engines, but they have huge, well deserved reputation.