hey guys, i need your opinion on this: fact 1, my turbo is burning oil(blue smoke come out from exhaust, and oil appears at compressor inlet and turbine outlet), what i thought was some kind of sealing inside the turbocharger was worn out. but after reading the article below:

Engine oil under pressure enters the bearing housing from the oil inlet line. This oil passes between the bearing and journal surfaces where, as a result of turbulence, air is mixed with the oil. The oil leaves the bearings looking somewhat like a "brown whipped cream", then falls by gravity to the sump at the bottom of the bearing housing. This foamy oil then flows by gravity down the oil drain line and into the engine sump. Anything which prevents this gravity draining will cause the foamy oil to build up in the bearing housing to a height above the oil seals. Under this condition, the oil will leak out into the compressor and turbine housing past the piston ring seals through he piston ring gap.

what i need to know is, how high the pressure could blown the sealing? because my oil inlet is not connected directly on oil sending unit behind engin block. i have a oil cooler before i put on the turbo, when i installed the turbo, i made a " T " fitting inline with the oil cooler. what i mean is: oil come out from engin, then go through oil cooler, then majority oil go back to engin, a small portion used to cool down the turbo. will this set up consider to be unsafe to turbo,(high pressure??? )

this was a used turbo, and i don't know if it was damaged or not when i got it. do u think my set up damaged the turbo???
any opinion will be appreciated.

 

well blue smoke and leaking from your inlet should be separate problems. i dont know about your oil leaking from your inlet but if your blowing blue smoke, your getting blow by in combustion chamber. so if you built your motor for turbo then maybe your rings didnt seal and set right, if you didnt build it..... well then maybe you should.. just my 2cents

 

hondas produce up to 60 psi of oil pressure to operate the VTEC motors properly.

turbochargers need less than 30 psi or you risk overflowing it with oil and/or blowing the seals.

 

If that's the case, why do so many people rave about VTEC + turbo?

 

Yokogsr:

The setup you have purposed should be fine. I've got a similar setup on my CRX. ON mine the turbo oil sending line comes from the oil send unit's hole. I usually see a max of about 50psi with an autometer oil sending unit between my block and turbo. I also have an external oil cooler setup with an adpater plate on the oil filter. Normally turbo'd honda's run about the right oil pressure to be safe on turbo's...even with VTEC. Go ahead and get your boost on :thumbup:

ur31337:

People rave about boost and VTEC b/c of the aggresive cam profile change that VTEC offers. This helps both in the N/A world and in the F/I world. With a larger more aggressive cam profile, you can force a larger volume of air into(and expell it from) the engine per valve event. VTEC usually give's you a nice kick in the pants when it switches over on boosted engines.

However, too aggresive of a cam with too much overlap results in what called "blow through". Overap is when both the intake and exhaust valves are open at the same time. In the N/A world overlap is good, it results in a power producing and a very top-end happy engine. In the F/I world both valves being open allows some of the boost to escape straight through the engine and not pressurize in the cyclinder.

 

when you buy a used turbo, then most of the time the seals WONT be in very good condition...not being used is as bad or worse than running them to death.....if you're turbo's seals are going bad, then you'll usually find oil somewhere between the intake outlet and the head.....usually, you will get blue exhaust smoke too....sometimes, when it's bad enough, it will leak from the housing itself after shutoff.......not that many parts to a turbo....when a turbo isn't allowed to cool down properly(not using a turbo timer) then the oil burns and builds up on the shaft.....eventually, something has to give...it might take 50K miles to prematurely wear it out, or it might take a few miles.....

 

thanks guys, now i can be sure what i am going to do next.