*Big* Smokey Moment... +?Blowby +?BHG... WTF?

[ed]

or fix the baffles

[kickn5k]

Gapless rings? I have heard with some bore material types that huge oil consumption issues will arise with gapless rings.
I run them in my 5K with the sc-12 on it and have no problems. But the old sierra cosworth GrpA cars used to empty the 8ltr dry sumps within 5-10laps.
Im probablly way off but just a thought.

stu.

[rolleraction]

Is the catch can vented to the atmosphere also? or only via the exhaust? Sounds to me like the exhaust vacume is the cause. Unhook & block then test IMO...

[RONA]

Gapless rings? I have heard with some bore material types that huge oil consumption issues will arise with gapless rings.
stu.

Would explain it getting burnt but not getting into the catch can

[ed]

Is the catch can vented to the atmosphere also? or only via the exhaust? Sounds to me like the exhaust vacume is the cause. Unhook & block then test IMO...

only via exhaust

ill try capping the main crank breather first as the cam cover breathers are unlikely to cause any problems

it does have gapless rings, and yup, she did eat a bit of oil in the old build. i tried a different assembly and run in procedure this time tho (only a rehone on the same rings too btw) and we'll see what the oil consumption is like

[kickn5k]

it does have gapless rings, and yup, she did eat a bit of oil in the old build. i tried a different assembly and run in procedure this time tho (only a rehone on the same rings too btw) and we'll see what the oil consumption is like

Yeah as there is no leak down, through the rings. It can bring out minor cyl head issues sometimes but it is rare. Another theory i had was that the rings might not have bedded properly and then load could cause blowby, but gapless rings are usually ductile iron comp ring not chrome so im leaning more towards a crankcase breather issue etc.

Good luck with it. Its a sweet looking 1UZ you have there.

stu.

[Celica RA45]

before you go any further are there any lines going to atmosphere like rocker covers to breath air in and out etc or do all of the lines go to the catch can then get sucked out to the exhaust ?

[ed]

before you go any further are there any lines going to atmosphere like rocker covers to breath air in and out etc or do all of the lines go to the catch can then get sucked out to the exhaust ?

all lines go to the catch can and out the zorst via a sturdy one-way valve setup. basically a closed system. no atmo vent

fwiw - no oil issues tonight in a 30-40km odd trouble shooting session. i simply drained the catch can, reconnected ALL the lines, checked the oil levels, and went for a test run. ill drop the catch can again tomorrow and check the accumulated volume, plus check the sump. i also engaged the accusump function tonight too, it was interesting to actually see it work having just finished driving the car without it for the past few days.

perhaps with the accusump loaded and with a litre or so purged out of the system, the oil level is now *right* ??

dunno, need to keep an eye on things.

also it does look possible to maybe be able to drop the steel sump belly with the engine insitu. fun happy times right there... :roll:

[allencr]

One end empties out raising the level, while the other end is overflowing with that one big hole aiming oil at or near your vent.
Did the test run/break-in have a lot of acceleration & deceleration pushing it toward the vent end?

[MWP]

Why do you have the crank/sump breather pickup at all?
I cant think of a good reason to have it since gasses will make their way up to the head and out of the normal/factory breather points.

Did you remove the baffling thats inside the cam covers?

You should turn that crank/sump breather pickup into the return line from the catch can.
Just move its catch can entry point to the bottom/underneath.
That way itll act as a pickup for gas, as well as a return for oil.

[YelloRolla]

Why do you have the crank/sump breather pickup at all?
I cant think of a good reason to have it since gasses will make their way up to the head and out of the normal/factory breather points.

One good reason is that the less pressure that you can keep under the rings, the better that they should seal.

[ed]

ok. checked the catch can today, and there was about 150ml of oil sitting in it after about 150km of reasonable driving. i also dropped the oi from the pan, and lo-and-behold it was about 1.5L under expected. so obviously the volume of surge of oil into the catch can came from this second oil change...

anyways, due to problems getting dyno time today, i didnt get to check all the pressures around the catch can and crank case, but did atleast assemble a pretty funky array of digital meters to hook up and monitor these things when we do finally get on the rollers...

[Celica RA45]

try running the rockers to atmosphere so they can at least suck in air and see how the catch goes from that try another 50 kays driving with catch can empty and check agian to see if it is full agian
did this happen on your last motor and maybe thats why it ran a bearing

[ed]

nope, new phenomenon with the new motor. the catch can had the usual shite and 200ml total volume (after 1500km) on the old motor in total. never a problem

yeah, considering running the rockers to atmo, but also kinda defeats the purpose of having the exhaust vac to lower the crankcase pressure

[frostyadonis]

sounds like too much oil, causing too much pressure in crankcase to build up, forcing oil past the rings through the cylinders.(happened to me once)

also, theres alot of oil feed lines coming out of the catchcan, you didnt connect one to the intake manifold by mistake did you?