2 Liter Beater

ok so i just recently picked up a supposedly rebuilt 99 gsr head. also a 99 b16a2 block, used not rebuilt. the pistons all looked great and the walls clearly showed the cross hatching.

current set up is stock b16a2 block, gsr head, 99 itr cams, s2 pro intake mani running on chipped po6. using a previously tuned engine with exact same set up.


so the problems was, at first, the pcv was dumping oil into the intake mani. i changed it and still same thing. so i blocked the second hole on the charcoal box and the spout off the intake mani. ran the car for about 100 miles and that pretty much burnt off all the oil in the intake manifold.


so now the only time it smokes, and this doesnt even happen consistantly, is after letting off the gas and using the engine to slow down say from 70 to 65. i push the throttle to around 50% and it puffs blue smoke. does not do it driving around town, under any regular or hard acceleration, just coasting down for 4k-ish rpm to around 3.5k.

does not smoke at idle or at start up. i can smash from a dead stop taking it to 8.2-8.4k each gear and there is no visible smoke...



im leaning toward valve guides or seals. just wondering if anyone has dealt with something like this and could give me some advice.

Thank you.

grjr

When you let your foot off the throttle @ 4k you are creating a high vacuum in the intake which can suck oil in through the valve seals/guides so that would make sense. You need the PCV system to be connected correctly to remove gases/pressure from your crankcase. Did you use a PCV valve from honda or aftermarket? You might want to open the oil cap while the motor is running at idle to check for excessive blow-by. Excessive pressure in the crankcase and high vacuum in the intake could be helping to force oil into your combustion chambers.

2 Liter Beater

i used an oem honda pcv valve from my previous engine. had it in and drove about 5 miles and when i checked it, it was very oily. never was like that on my other engine. i have read that higher compression will create more blow by, but where should i run the hose off my breather box? i had two pcv valves between the black box and my intake manifold yet oil was still dripping into the mani. would a catch can solve this?

i know that i really shouldnt have it blocked off and that it needs to vent, but i cant run it straight to the intake manifold. if i do, it coats the entire inside on the manifold with oil...

oh and another thing is, the stuff in and around the ends of the pcv valves i used were very black like old used oil, yet when i pulled my throttle body off the oil inside of the manifold was fresh and golden still. dont know if that means anything but i was expecting it to be black like the pcv valves..

2 Liter Beater

ok so i've been reading up on pcv systems and catch cans. im thinking there is just too much pressure in the bottom end with it blocked off.

im thinking about just routing the hose that is supposed to go to the intake mani straight to the ground. no pcv valve of course as there will be no vacuum to draw it out. anybody else try this or have experience/probems doing this?

el crapitan

that's all they did before the valve was created.
emissions is the only backdraw

2 Liter Beater

just tried it and it still smokes lol

also when i pulled the straight spout off out of the breather box there was coolant around the rubber seal. couldnt see any in the box and im not leaking any.

there must be something bad inside the engine. which is awesome because i just pulled my b20 due to having bad rings and burning oil... i have the greatest luck with engines haha i guess comp test and leakdown are in order.

also just curious but how difficult is it really to replace the rings. ive read and watched videos of several people renting honing stones and doing it themselves which doesnt seem that hard. ive torn a few b series completely apart so im fully aware as to how it all goes together along with torque specs and what not. any good advice for a first timer? trying to save my b20

grjr

did you remove the oil cap with the engine at idle to see if it's blowing out any smoke or excessive pressure?

2 Liter Beater

just tried it. there was no smoke but im not sure what excessive would be pressure wise. ive never taken an oil cap off at idle. there was a fair amount of air coming out and it had a dull hum to it.

Acid X

Did you ever resolve this issue? I have a gen 2 b16a that has the same issue. Exactly the same. smoke only from 3.5-4k ish on decel.

Everything in my engine is literally brand new top to bottom. completely rebuilt head with new guides and seals and fresh home and ring job along with all the other bells and whistles. Over 1000 miles on the engine now and still exactly the same. I can blast out to 8000+ and let it decel hard and no smoke? Doesn't make sense!