Rb20 Freshen Up.. Diy Job ?

[esky_mad]

The RB20 in my partners 32 started to pump a bit of white smoke last week, so we pulled the turbo and hoped that was the problem. it was replaced with a good condition Neo RB25 turbo but its still got puffs (albeit much smaller ones) of white smoke coming from the exhaust every now and then, and when the oil cap is opened, what looks like mist is coming out. i believe this is blow by ?? we will of course get a comp test and/or leak down test to confirm.

Its only recently had a catch can installed, has two outlets. cam covers are connected to one outlet, while the other goes back to the PCV valve on the intake manifold. which i believe to be correct as we dont want one going back to the intake pipe.

ive done bits and pieces on my previous cefiros and my partners old 180SX, mainly dropping and fitting motors, gearboxes, removing turbos and manifolds more times than i can remember, and doing timing belts, tensionsers etc etc. im not to concerned about stripping the motor as ive stripped down a motor before (that was thrown in the bin though) but im not sure what i should be looking for in terms of the bore in the block, what rings do i get, what measurements do i make for getting the correct bearings ?

i have had a look at the engine manual before but its all a bit confusing...

and no we are not swapping in a 25.. plus it seems a better option to freshen it up than throw in another 20 thats on its last legs.

any info is appreciated, no flaming is required. backyard mechaincs have to learn somehow..

cheers.

Edited May 30, 2010 by esky_mad

[blaikier33]

i wouldnt have done the catch can that way because by joining the the cam cover breathers into one on the catch can is halfing it breathing, like if we all woke up one day with one lung.

if it was a decent catch can it would have baffels so u could run a pipe back to the intake pipe without oil contamination, and put a third hose fitting on the can so u can have one hose from each cam cover to there own inlet on the catch can, then one bigger hose from catch can to intake.

also check your pcv

i dont think its breathing enough though the one hose

[esky_mad]

the catch can is a generic two outlet, so having 3 outlets is easier said than done.

ive seen plenty of catch cans set up like this and havent had smoking issues, i figured if its breathing enough that two hoses into one causes issues (it goes into one hose just before it hits the catch can) then the culprit is something much more than the catch can.

but im more than happy to be proven wrong..

[blaikier33]

well that is what i did with mine i drilled and taped a new fitting on the top and ran one big hose to the intake pipe, and i left my PCV as is, fron drivers side cam cover to intake man

ime not douting you and ime no gurru. but you have two rathe large hosses t into one, then into catch can then into a tiny pcv that will caus crankcase breathing isues

a pcv valve is a one way valve its open when the engine is OFF boost which is vacume, your engine it will be breathing a bit then.. but being a one way valve when your making boost this valve is shut, so its not alowing boost to go into the engine, which is normal that is why they also vent to intake pipe.

so when you are on boost were is your crankcase pressore going. nowere. this is how you blow seals and destroy engines

[esky_mad]

if i leave the PCV alone ive only got one hose running to the catch can, as the smaller outlet on the cam cover isnt suitable for the engine to breath, so they are looped together as from factory. custom intake pipe doesnt allow for it to be plumbed back in which is a pain but the original intake is stuffed.

appreciate you input either way!!