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Hey guys I need Advice,

Ive not long had my engine rebuilt (approx 5000ks) with ACL forgies, new bearings etc etc.

what i want to know is why the hell am i getting so much blow by.....had a look at the turbo inlet hose yesterday and the breather hose is soaked in oil and so was the compressor wheel!!!. It has a catch can on it which run from the factory PCV hoses into the catch can then into the factory PCV pipe to the inlet.

just took that hose off because the donk was injesting way too much oil.....it doesnt have a smoky exhaustand the turbo is fine.

At idle when it is cold or at operating temp the breather hose resembles a steam train.....

the engine was run in as i was told to and it has fresh oil in it.

running std turbo (max .8 BAR) and PFC

Have I glazed the Bores? or is it my cylinder head which wasnt touched after my donk split an oil cooler hose and ran dry of oil

oil pressure at operating temp is 2Bar at idle and 4 Bar at 2500rpm

Only other thing i can think of is that it has an oil leak from the front of the motor that looks like its coming from between the block and the head but dont exactly know.....dont want to pull the cam gears off to find it.

soz for the long post but i wanted to cover all bases.

Regards Andrew

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Ive noticed that piston to bore clearances are fairly up the shit with many of the US pistons atm (cant remmber the acl specs though), what are the ACL clearances on the particular model you have? I just finished a few ARIAS forged build and always go way smaller in the piston to bore clearance than recommended. Its seems many have a generic clearance.

But dont panic and keep it simple, check things like pcv, baffles in rocker cover etc..

Edited by URAS

not sure on clearences. car doesnt have PCV any more just the joiner hose for the cam covers then into the catch can. as it was taken off for the catch can.....engine never did it before it blew up i know forgies sit sloppier in the bores when cold than cast ones but its doing it when hot which is what i cant understand.

also any idea where this oil leak could be coming from?

thanks for the advise guys

  • 2 weeks later...
not sure on clearences. car doesnt have PCV any more just the joiner hose for the cam covers then into the catch can. as it was taken off for the catch can.....engine never did it before it blew up i know forgies sit sloppier in the bores when cold than cast ones but its doing it when hot which is what i cant understand.

also any idea where this oil leak could be coming from?

thanks for the advise guys

Do you know what kind of condition your turbo is in? Could be a bad oil seal on your turbo allowing oil into the compressor housing.

Did you plug off the PCV valve on the valve cover? Try running just a breather filter on the outlet side of the catch can and see if that clears up the oil situation. If so, you need to find a better way to remove oil vapor before returning it to the intake or your turbo oil seal needs replacement.

if you've allowed your pcv to be free flowing from the crankcase - catch can, and your catch can is recirculating back into your intake then you'll get what seems to be blow by. theres a reason the pcv valve is a 1 way valve - it doesnt let the OIL from the crankcase into the head, or in your case catch can.

reconnect the pcv with the valve on it in properly then clean out your intercooler piping and go from there. while the pipes are off check for shaft play in the turbo.

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