could a motor being massively out of tune lead to oil consumption?

[trad1987]

I have a s14 sr20det with huge 272 cams, bc valve springs and retainers, t28 turbo, big ass fmic, non-recirculating hks bov, bored 10 over .... WITH A OEM ECU. it burns oil only when under heavy throttle. its not visible, but it goes through it. Anyway, im confused cuz it was rebuit 8k ago

if its super out of tune, could this lead to oil consumption?

[slider2828]

The oil has to go somewhere... Really not out of your pipe or turbo? Check for oil leaks?

[steve shadows]

Originally Posted by trad1987

I have a s14 sr20det with huge 272 cams, bc valve springs and retainers, t28 turbo, big ass fmic, non-recirculating hks bov, bored 10 over .... WITH A OEM ECU. it burns oil only when under heavy throttle. its not visible, but it goes through it. Anyway, im confused cuz it was rebuit 8k ago

if its super out of tune, could this lead to oil consumption?

Why in gods name are you running a stock ECU on that?

You probably blew the motor or oil is leaking through your rings.

You have WAY TOO much air and probably way too much fuel and the fuel can soak the cylinder and the air if not tuned right can cause wierd heat zones and pressure zones which can break things really easily.

PEOPLE YOU HAVE TO INVEST IN A GOOD ENGINE MANAGEMENT SYSTEM FIRST!!!! BEFORE ALLL THE CRAZY ENGINE MODS!!!!

Please get a PFC and at least a base map for it through me or something,
but first make sure you check yoru compression with compression tester (make sure to hold the throttle open while you crank) also to remove the fule pump fuel before you do the test as well as the ignitor chip

also then make sure your Crankcase is getting vacuum from the intake pipe before the turbo- search if you dont knwo what I mean

[SoguRacing]

explain how it can burn oil running a bad tune? oil has nothing to do with the tune..
also, the pcv valve doesn't get vacuum while you're boosting. only under decel or cruise will the pcv valve open on forced induction cars.

[Sileighty_85]

Improperly tuned= too much fuel=cylinder wash=worn piston rings=oil consumption/massive blow by

and or

Not enough fuel= lean condition= over heating= wearing down of piston rings=blow by=oil consumption

regardless the kid dose not need to be driving the car, I cant belive you've been driving the car for 8K like that



When you bored out the cylinders did you get oversized pistion and rings or just slap new rings on the originals?

[steve shadows]

If he never had it tuned int he first place he could have cracked a ring land or blown out a piece of the head gasket

did you read the part about cylinder pressure I just wrote? and heat zones.

Also the condition of the flame front in burn pattern on surge in on depending on momentary VE efficeincy changes in the head can lead to heat swamp which can really mess up your flame front/ burnt pat..etc

[SoguRacing]

that still doesn't explain the pcv valve function under boost. sil85, blow by is when combustion chamber gasses blow by the rings into the crankcase..not the other way around. still doesn't explain oil consumption for an untuned car.

[Sileighty_85]

Right, where does the oil come from when ppl use oil catch cans and have blow by?

if hes not running an oil catch can and just routing the CC breather valves back to the intake it will cause him to burn oil

[steve shadows]

Originally Posted by SoguRacing

that still doesn't explain the pcv valve function under boost. sil85, blow by is when combustion chamber gasses blow by the rings into the crankcase..not the other way around. still doesn't explain oil consumption for an untuned car.

If the car wasnt tuned and it cracked a ring land it would consume oil like crazy.

That simple,

I don't understand what you are debating with me? lol

PCV Valve fucntion under boost is to CLOSE itself and not allow pressure into the head and crank case. The PCV valve is on the intake manifold side of the SR valve cover.

The crank case vent is something different. That is the hose coming up on the exhaust side of the sr motor and connecting to a catch can and then the valve cover T and then the Intake Pipe in front of the turbo.

If this is not connected properly and the car is not tuned properly (ie it is bogging and under a lot of stress and wierd load conditions) you will see a bit more burn off from funky pressure zones in the crank case. It is really simple, when a motor is running very rich or has wierd very sporadic load due to very bad tuning on the motor you will get wierd load cells being hit in the map in the computer and the engine will be put under a very sporadic and random load events which in theory could cause more stress and more wierd pressure or vacuum surges in the crank case, rather than a motor running 100% smooth with stoich off boost map with no fuel leaking by rings an with perfect crank case equilibrium and steady load conditions in all gears (with no wierd surges or rough tough load patches)...

I actually had this happen when I first started tuning a haltech once. Once we got the motor running good it stopped eating through a quart of oil (tired bottom end on a customers car) and then finally once we re-cired the crank vent it was totally gone. was eating a quart of oil every couple of weeks and you could see the burnoff on the dyno when the car would hit funky load regions or wierd tractive effort load cell zones where it wasnt tuned right, you could actually see more burnoff sneaking through the crank vent t intersection

You must have the vacuum hooked up to your crank case VENT, not your PCV. PCV is almost irrelevant in this case. As long as it is working condition of course

[steve shadows]

Originally Posted by Sileighty_85

Right, where does the oil come from when ppl use oil catch cans and have blow by?

if hes not running an oil catch can and just routing the CC breather valves back to the intake it will cause him to burn oil

not really

It should actually do the opposite either way.

The catch can helps, but if you are sucking oil through your re-cir from crank that much then you have bigger fish to fry.

Having the crank hooked up to vacuum will always help lessen burnoff, even if it's directly to the intake (you will just get a much dirtier piping system over time)

[Sileighty_85]

Originally Posted by steve shadows

not really

It should actually do the opposite either way.

The catch can helps, but if you are sucking oil through your re-cir from crank that much then you have bigger fish to fry.

Having the crank hooked up to vacuum will always help lessen burnoff, even if it's directly to the intake (you will just get a much dirtier piping system over time)

But thats if his rings are good correct? I know hooking the CCB to the intake will help the rings seal

But
If his rings were worn and had blow by then it would cause him to blow more oil out correct?

[steve shadows]

Originally Posted by Sileighty_85

But
If his rings were worn and had blow by then it would cause him to blow more oil out correct?

exactly.......

so check it with compression tester and leak down first and stop drivingthe poor car until you at least have a base map on it or something

[trad1987]

Yes my crank case breather is hooked up to the intake pipe and there is no catch can. Out of curiosity, what is the valve cover vent on the rear of the exhaust side?

[slider2828]

What valvecover vent? that is hooked up to the crank case?

[Sileighty_85]

Originally Posted by steve shadows

exactly.......

Alright, that what i was referring to in my post

Originally Posted by steve shadows

so check it with compression tester and leak down first and stop driving the poor car until you at least have a base map on it or something

Steve Has Spoken

[teamsprock]

Since he has an S14 SR the crank case breather tube goes from the block and back into the valve cover at the back, then there is another vent in the middle of the valve cover that is the breather that you would hook to a catch can/intake. This is the reason people love S14 valve covers, running the crank case vent up to the valve cover you blow any oil in there instead of the factory S13 black catch can. This helps baffle a lot of the oil flying around and keeps it in the engine rather than the catch can/intake system.

Steve is very correct that having the catch can system hooked up correctly will help the pressure get out of the way of the pistons which reduces blow by and also seals up the other seals better. Both of these help the oil do its job and stay out of where it doesn't need to be. The less blow by and crank pressure the less all the seals have to work. I can't believe I just said Steve was right, ha ha just joking Steve.

Also there is no reason to do all those mods if you are on the stock ECU your not making the power you will when you get it tuned right. I know everyone always seems to put engine management last on the list but that really should be a priority.

[ManoNegra]

has anyone mentioned valve steam seals?

[steve shadows]

it would be BURNING lots of oil tho


it sounds like he is just loosing it into the catch can