Hello subaru people well I am a new member on this form and had a couple of question I recently bought me an 05 subaru wrx sti and I bought the car running good a week later the engine started knocking and so I replaces the short block with a brand new short block I replaced the oil pump oil pump strainer timing belt,tensioner, water pump,and a full gasket set I then drove the car for about 160 miles and just today it started making the same knocking noise I didn't hot rod the car cause I was letting the piston rings and everything break in what do u guys think might have made it spin another bearing???

Welcome to the USMB.

 

I'm going to move your post to the new gen forum where it may get some more views.

 

So what parts did you reuse and which did you get new?  What brand of parts did you use for anything that you replaced?

Did you use RTV on the oil pump?

Does it have an oil cooler? Did you re-use it?

Firstly has the engine been stripped, A spun bearing means the bearing has rotated in either the connecting rod or cases and the locating tags have not stayed where the notches are.

 

In the case of connecting rods and crankcases the bearing are located by a 'crush fit" meaning the bearing outer diameter is slightly bigger when fitted to say the connecting rod than the inner diameter of the assembled connecting rod thereby clamping the bearing so it does not rotate or spin with the excess friction induced by the differing diameters, The notched part  and the tag on the bearing shells do not stop bearings from spinning remember that.

 

The notches and the matching protrusion on the bearings are simply for locating not to stop a bearing 'Spinning' as people think.

I doubt your bearings have actually spun, but have more likely failed due to lack of oil pressure or flow through the passages in the crankshaft and or block.

 

Cleanliness is vital as is unobstructed flow and pre lube when assembled with assembly lube, Blueprinting is the art of making sure all measurements and clearances are correct to factory specifications if all of the above are followed and good quality parts are used by an experienced technician failure is not an option.

 

These parts are all metal therefore they cannot think and therefore they cannot fail.

All failures are Human related, someone did not either design , manufacture, maintain or use the  metal components correctly as metal cannot think and therefore it cannot fail, same goes for the oils and coolants used, can't think can't stuff up remember that all failures have a human in the chain of failure somewhere who is ultimately responsible for that so called Mechanical failure