i had seen few cultus caby model that are suffering from excess oil blow on higer rpm at highways that oil suck by airfilter chamber and smoke screen through tailpipe , even one of mine friend gone for full overhaul and was suffering the same problem again. same happens to me aswell as i double check rings while head was off but after on highway same **** happens and its embarrassing, what i have to do just keeping in mind to soft foot on higher rpms. but some time it dont work.
was browsing on G10 engine problem found that
"Imagine if you will, what's happening up on top of the head at freeway speeds: The motor is turning at 1800+ RPMs, and because of the increased gap abnormal amounts of oil are bleeding out around the worn camshaft bearing surfaces. The excess oil can't drain off the radiator side of the head fast enough (which may be why they recommend 5W-30 rather than 10W-30 oil?), and since the firewall-side head gasket drainback holes are so tiny, oil can't drain past them fast enough either. So, the oil eventually fills up the firewall side drainback holes, and once they've filled up, what happens? The oil begins to flood the top of the head, with the level gradually rising around the bottom of the valve springs that are rapidly being slammed up and down.
Up above this rising tide, you have the cam slinging and splattering oil all over the inside of the valve cover with the lobes slapping against the top of the hydraulic lifters, pulverizing the oil there into tiny droplets, which is all fine and good as far as that goes, but if you haven't figured it out by now, the real kicker comes with the increased oil pulverization that's occurring down below around the valve springs that are becoming steeped deeper and deeper in the pooled oil...
At these high RPMs, in my mind's eye, it becomes something akin to a fog bank on the inside of the valve cover, only it's an extremely violent environment. Now, add the crank case blow-by gasses coming up the drainback channels with the increased vacuum coming from the lower half of the air filter housing as the motor is sucking in huge amounts of air and fuel down the throttle body (yeah, yeah, I know... it's only a 1 liter engine), and, well, there's going to be a draft carrying those tiny little oil droplets right up and out the top of the valve cover, through the PVC vent tube and into the air filter housing, resulting in an oil-soaked air filter housing and throttle body and blue smoke behind:
Xperts what your opinion about that can you please !!!