Hi guys,
Just thought id add my experience with my b4 for future peoples bearings.
i have a 00 subaru b4- Blitzen model i will add, bright red in colour with the blitzen body kit and porsche wheel matched nicely to brilant blitzen suspension).
any way earlier on this year i too done a bottom end bearing,being number 4, and i struggled to sort out what to do.
it came to a very lucky circumstance where i found a brand new 2.5l short motor(so run in at factory with pistons and the lot) for only $500,it was assembled at subaru in melbourne but once assembled it was found that it was droped and the part of the cast on the block where a blot for the cam cover was broken off(big whoop it was on the bottom of the engine and not in to bad a spot).
either way i took part my old engine and put it all back together with new gaskets(use the two litre head gasket), easy swap over of parts mainly(remember to take the clucth fork pin out else the motor wont come off as i found).
only probly with parts on the B4 is that the clutch is expensive and i had to get an exedy clutch($500 trade) and the timing belt kits generally have mixed up parts(right belt wrong pullies or viser vercer).
after putting it together (and finding this absolutely strange phenominom with the oil presure on the oil filter adaptor) it starts rather fine.
final look. the 2.5l block works perfectly fine(i brought it as a non turbo block to i should say) only thing like most new subaru engines the have a large amount of piston slap when cold, first time started itll slap for like 20 mins at idle.
only modifications ive done have been the new block, oil filter adaptor with oil pressure gauge(fits perfectly under the cigerett lighter) and i put in an octane booster every 3 or 4 tanks(nulon works great)
i should say that to run the engine in, i let it get cold as few times as i could (so drove it all sat and all sunday). at first the first 2 hours i drove easy as youd expect with up to 50% throttle with out reving it to high(trust me above 2000rpm 50% is heaps 5000 is to much as the piston slap with let you know), trying to let it full off throttle many times(maybe give it a poke to 70% if you have it fully heated and good 98+ octane fuel).
after that driving up to 80% often and off often, best way to me to run an engine in is to try and put load on and of the rings, but not to long as youll heat them up to much.
after 4 hours your well into safe area of full throttle (i did it much ealier), try not to let it idle for long.
the piston slap for me was gradually wearing away the more i drove it(trust me the noise it made at first made me not want to drive it but it was much better later on), the higher the revs the more slap youd get, so keeping it low helps.
now bout 4 months after being put back together, being a daily driver, driven it bout 7000kms, it only slaps for 20secs when bone cold and up to a min if you dare rev it to high.
the engine thou. is amazing, puts the gear box to absolute shame because the gears feel so close, usually i go 1st ,3rd ,5th usually droping it to 2000rpm to drive, lower then that the 4cylinder still pushes hard, but shakes any lower then 1500.
the tourqe is amazing and puts most v8s to shame(not one has bet me to the speed limit yet).
as for turbo's, both tubros spool the same psi, after all you still have the same space in the valves to squeese the air through, but yeah round .7 bar on primary and .9 on secondary if that turbo's cold or up to arou 1.1 when its hot. as for 'VOD' pritty much kiss it goodbye.never feel it, sticks on the same psi until the secondary rears up and man at 1.1 when its hot it goes, you feel it imensly, usually a problem for me cause pens or usb sticks want to stay in the same spot but the car thrusts forward.
only problem you get is when you change gears just after the secondary kicks in, it can stick in twin turbo mode at 3500rpm for bout .3 to .7 of a second.
no pinging or anything wrong yet but never skip more then 3 tanks with out octane boost, no ecu tune either.
