Has anyone rebuilt a junkyard engine? Some of them seem quite cheap with not bad mileage (100-200,000km). What should I be aware of when looking for a junkyard engine to rebuild? I might not have to do any rebuild if the engine seems to run fine at the junkyard.

 

First make sure the crank turns. Then a leakdown test to see if there are any bad valves or piston rings. Check timing belt, sensors and so on. If the engine runs fine at the junk yard, do a compression test and see where you stand. Also check the underside of the oil cap, white sludge means it went on a lot of short trips. Check the spark plugs for irregular burning patterns. There's probably more but I can't think of anything else right now.
I'd also check some engine rebuilders and see if they have any spare heads or blown motors that they were going to scrap anyway. They're a great place for spare parts for mini-me swaps or LS/Vtec swaps and they could also do some port matching or head milling for you.

 

the worst thing you could buy would be a block with a damaged sleeve, but thats hard to diagnose on an assembled, non running vehicle

 

just make sure the sleeves arent oval shaped or destroyed, unless your getting it sleeved, then it wouldnt matter

 

Don't forget your lucky penny.

My rule of thumb is to get engines from cars that where obviously totalled in accidents. The engines are virtually always good in them because they weren't junked for mechanical reasons.

 

I bought a b18b short block out of a totalled integra for $100.
As long as youre rebuilding it there is not a problem.