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

[ONETEN]

OKAY my suggestion - Check out the 1 way valve on catch-can to exhaust line quicksmart. Withe more than one breather, i can see exhaust pushing up into the catch-can, pressurizing it which is in turn is pressurizing the engine via the breather lines... But once the motor has pressurized with exhaust gas to a certain point, 1 or two of those breather lines will begin to route the exhaust gases back into the catch-can (as no other means of escape) and will take a shite load of engine oil with it. Once the catch can fills, pressure in the can would over come the pressure from exhaust system into can and begin to dump oil into exhaust until can empties enough and the whole cycle starts again...

One thing that is obviously a fact: You filled a 2L catch can in 120ks of driving, so your crankcase is DEFIANTLY being pressurized from some source or another.

The only 2 things i can suggest to rule this out:

1. Run the motor until shes good and hot, then shut her down and pull the dipstick while listening carefully, and if the crankcase has even a small amount of pressure you will likely feel it, smell it and hear it if you face is close enough.

2. Disconnect that exhaust return line from the catch-can, and continue to run it in whilst keeping an eye on catch can very frequently. If it stops filling the can, then you have found your source of crankcase pressurization.

Lastly, and as much as i hate to say this, there is a chance the builder has fucked your clearances, used the wrong rings or some other machining error... The most obvious source of pressurization if its not the catch can would be compression leaking down past the pistons into the crank case. I have heard of forged pistons (not actually sure what internals you are running?) that have very slow heating/expanding properties and have pretty severe blow-by during the first few hundred kays of run in, but dont know if this is a myth as i have never experienced it.

If this doesnt help, it may be an idea to do a quick mspaint diag of the catch can & hose routings so we can all get a clearer idea of the setup.

Good luck, i hate to see a setup as nice as that with teething problems


EDIT: Shit, just noticed this thread has another 2 pages of posts seeing as i CBF reading them, i hope my suggestion will still help shed some light.

[Celica RA45]

edd have you got a better pic of your super dooper sump with door flaps .your pic shows 3 welded spots on the top plate covering the trap doors .is the steel plate on top fitting very close or is it loose so oil can slosh over it

[ed]

glenn, theres about 3-4mm open space around the edge of those top plates so oil can slosh down the sides

ONETEN - the current plan is to run a full dyno session with pressure logging of the exhaust line pressure, catch can and crankcase pressure. one i ve some data ill have a better idea of what is pressurising what and when, and then ill start to disconnect stuff to see what happens. it is possible that the one way valve isnt working, but that'd be pretty unusul as the valves are actually 2 stroke reed valves....






cheers
ed

[Celica RA45]

i would be inclined to make some brackets so you could bolt the top plates down so you can clean easy and make them tight so no oil can slosh around
also the left pic shows a hole i gather that is for oil dip stick i would raise that as put a 22mm tube over that so oil doesnt slosh around
the 3sge engine has the same pan but with a hole for oil pick up and the top peace is welded in and is tight right around with a 10mm lip to stop oil coming up and a 30 mm tube in height to stop oil surge for dip stick
the vent that you have welded to go to your catch can isnt in a good place and under load could be pushing oil up
on my motor with out pvc valve blocked off it will push oil out into catch can
if i run t
2 oil hoses 1 vent from rocker cover and also where pvc use to be it hardly has any oil in catch can
me thinking your exhaust is sucking to much

[KGB]

Try a vacuum gauge to see how much the exhaust is actually pulling maybe your set up is to efficient ..
Do a leak down test too its a new engine with gapless rings so blow by is at a minimum or non existent , so it sucks the next best thing oil

Are the valve covers vented ?

Keith:

[CrUZida]

Ed, can we get you to draw a diagram of the whole venting system ?

[YelloRolla]

The motor stage 1 had the same venting system. What we changed was the sump/oil pick up arrangement - closing a smaller "sump area" around the pick up with flap gates (a pet hate of mine) with a lid over the outer reservoirs of the sump.

I believe that this causes the oil level to sit up too high with the engine running. This would account for the taper in the engine power, as well as explain why the engine is not burning any oil.

[oldcorollas]

how does the oil get into the "wings" of the sump? are the gates held open a little bit during straight driving? or they sit sealed and the oil is only in the centre section?
gap at the bottom?

[ed]

I believe that this causes the oil level to sit up too high with the engine running. This would account for the taper in the engine power,

jase, theres still TWO windage plates (one solid plate one screen mesh) between the sump belly and the crank i dont see how oil level sitting say an inch higher would effect power?

stewy, theres enough gaps to let oil 'flow' around the trapdoor flaps, but the general obstruction keeps major 'sloshes' contained centrally around the pickup

[YelloRolla]

jase, theres still TWO windage plates (one solid plate one screen mesh) between the sump belly and the crank i dont see how oil level sitting say an inch higher would effect power?

stewy, theres enough gaps to let oil 'flow' around the trapdoor flaps, but the general obstruction keeps major 'sloshes' contained centrally around the pickup

Yeah forgot about those.The oil being pumped around the engine when it is running will be heaps (technical term). I reckon that we could easily see more than an inch of oil over where it was originally, maybe 2 or 2.5". This is obviously all guess work though. Like you said originally though Ed, it is probably more likely splashing up over the baffle plate.

The way that I was looking at it when I wrote that was simply this - we have 0.6L (educated guess?) more capacity, flowing into a sump area that it is < half what it was. Sure we left some gaps, but how much can they let the oil past when we are talking about 60 litres (another random number because I am on a roll) per minute of oil pissing in and out of the sump?

[NME308]

Hey Ed,
Hope you find a simple solution...
But...
My last, and I do mean LAST, Holden V8 engine was a 355 stroker with all the fruit. The oil catch can system was the health bar on that engine!
The first pass down the strip with fresh motor smoked out the entire facility with white oil smoke from catch can vented to header collector (abort meeting). I changed to a moroso vacuum pump cos my engine builder reconed the header vent system must have provided too much vacuum...
The result of the next pass was different only that instead of turning the excess oil into smoke it blew it out the catch can breather and oiled down the full length of the strip (abort meeting with track staff threatening to permanently ban me...). Engine builder now says my breather from the back of the manifold is at fault cos its sucking all flying oil droplets from the lifter valley. The breathers were placed high off the tappet covers.
The only reason I did'nt spit oil onto the track for the next meeting was I had installed a complex baffled 15L funny car style catch tank in the boot. I would drain a coke can of oil per pass.
When I finally convinced the engine builder to pull it down there were 2 pistons with the ring gaps perfectly lined up and badly blown head gaskets into the lifter valley.
With the ring gaps fixed and fresh head gaskets there would only be a few mils of methanol per pass coming out of the breather tank. Whenever the engine was starting to hurt (which it did on a VERY regular basis hence it getting the boot) the volume of oil in the catch can would start to increase dramatically.

The point of it all is neither of the two devices we are talking about are liquid pumps (vacupan style exhaust header breather or moroso vacuum pump), they are air pumps designed to create a small vacuum in the sump. They will ONLY be able to pull oil out of an engine IF there is vast quantities of air passing through to suck any flying oil droplets with it.

Is there any way that this (might I add very fine looking) engine of yours could be allowing large quantities of air to be drawn through the motor by the header system other than poor ring seal/blown head gaskets? Every other orfice allowing air into the engine needs to be sealed to allow vacuum system to operate properly.

If the other guys torkey test(?) is the same as a cylinder leakdown then it would be very useful to get it done!

Cheers,
Jason

[ed]

They will ONLY be able to pull oil out of an engine IF there is vast quantities of air passing through to suck any flying oil droplets with it.

OR

if there exists a small pressure differential AND the pickup is entirely submeged in oil... a very effificient way to transfer a good quantity of oil and no, no other leaks,or way in for air to move. its sealed up toight

look, i just dont know. once the engine purged itself of the 1.5L or so of oil, it ceased to be an issues. no oil burn, no overflow, excellent compression and general running etc etc. and as ive said above, i havent had the chance yet to look at all the actual operating pressures/vacuum etc that exist in all these closed spaces

its now got a refill of 4.8L of fresh oil and an empty can, we'll see what happens. worst case we try and undo the stell sump belly and readdress the baffling?

cheers
ed

[oldcorollas]

it certainly is baffling

[YelloRolla]

it certainly is baffling

Boom boom Stewy

[Draven]

you're just lucky you're in Japan Stu