alright lads,just got my engine rebuilt and it keeps blowing the dipstick up a bit.this wouldnt annoy me that much only its spitting oil onto the hot manifold and it could start a fire
anyone have any ideas on what causing this?
alright lads,just got my engine rebuilt and it keeps blowing the dipstick up a bit.this wouldnt annoy me that much only its spitting oil onto the hot manifold and it could start a fire
anyone have any ideas on what causing this?
throwing up the dipstick is a sign of piston ring failure, but just to be sure check your breather pipes, if these are blocked it can also cause thisOriginally Posted by moons657
alright lads,just got my engine rebuilt and it keeps blowing the dipstick up a bit.this wouldnt annoy me that much only its spitting oil onto the hot manifold and it could start a fire
anyone have any ideas on what causing this?
my bro's car does the same and his car is perfect...ah dont be saying thattheres only bout 900 miles on her since rebuilt as well.
that would be a worst case scenario, ive seen it happen when people put in catch cans and dont have a breather on them too.my bro's car does the same and his car is perfect...ah dont be saying that
yea have a catch can.have the crank case breather going into the rocker cover then onto the catch can then outta the catch can into atmosphere...that right?
ya, thats sounds about right... did you compression test it?
no that was my next plan.has my head wrecked.thanks for the help man
it could be blowby caused by the rings not bedding in yet. have you driven it hard in the 900 miles? what oil was used to run it in?
mine is doing the same. i have just taped the stick in place lol.
How much power are you pushing out of the engine?
Blow-by will increase with increased cylinder pressure, so upgrading your breating system might be a good idea. Is your catch can connected to the turbo side of the rocker cover only, or also to the side facing the inlet manifold?
The breather opening at the inlet manifold has a small check valve in it, making the opening about 6mm effective diameter, instead of 10-12mm which is possible if you remove it.
Here's a picture of my setup. I use 8-an lines, but reccoment others to go for 10-an as I still struggle a bit with crankcase pressure.
vta breather systems
May I ask why?
you've got nothing scavenging the crankcase of blowby - meaning that any exhaust, fuel vapour, water, and corrosive hydrocarbons will be mixing into your oil. recirc breather systems use the intake to draw the blowby out of the crankcase and burn it. if your catch can is working properly it should condense this water/fuel/hc/oil mist into a foul mixture which can be drained, and then allow just virtually clean air back into the inlet tract.
the only benefit of a vta breather over a recirculating pcv system is that a cheap catch can won't condense the nasty stuff out of the fumes that are being redrawn. in this situation the best thing to do is to modify the catch can with some thick steel wool and recirculate it.
oh and i forgot to mention that blowby in the crankcase is potentially explosive...
So your main issue is that the turbocharger is sucking the blow-by out of the crankcase. I can see that, and it's probably nice to have the nasty fumes go into the engine instead of the coupé fan
But I find it hard to believe that the vacum created in the turbocharger inlet is big enough to create a noticeable vacum at the valve cover outlets. If one would disconnect the crankcase breather hose going to the turbocharger and put ones thumb on the opening of the hose, at VOT, would there be any noticeable vacum?
Oh, another small advantage of vta systems. Oil reduces octane numbers drastically, and makes a right mess of the IC piping if the catch can doesn't separathe the oil out properly. Oil inside the IC might even reduce its cooling ability.
the air is travelling the other way mate - it comes into the breather system through the pipe before the turbo inlet because it's being drawn out by the vacuum in the inlet manifold via the pcv valve
Oh, another small advantage of vta systems. Oil reduces octane numbers drastically, and makes a right mess of the IC piping if the catch can doesn't separathe the oil out properly. Oil inside the IC might even reduce its cooling ability.as said - with a working catch can there should be virtually clean air going back into the engine.
The pcv valve at the plenum inlet is very small. Second, it is only sucking air when the pressure is below 0bar boost. At VOT, when the most is breathed, the pcv valve is closed, and the air has to go into the turbocharger. That's when I'm wondering if the turbocharger is creating enough vacum to actually create a lower valve cover pressure, than if both exits are breathed to the air.
you're not on wot all the time. the crankcase will be evacuated between gear shifts the normal way. there will be a small draw through the turbo on boost, which is what causes the ic and pipework to get coated with a film of oil. using my amazing mspaint skillz i've drawn a diagram to illustrate the normal scavenging flow of crankcase fumes on the blacktop bentcam
the redtop is slightly different as it has a t-piece on the front exhaust side cam cover from the crankcase instead of the direct feed to the rear
ive only started to drive it hard in the last 10 miles or so.10 40 semi synthetic was used to run it in
seen this done a lot on the drift cars over here.little spring holding down the dipstick
shes only running 0.7boost.the catch can is just connected to the exhaust side,maybe i should look at the intake as well...How much power are you pushing out of the engine?
Blow-by will increase with increased cylinder pressure, so upgrading your breating system might be a good idea. Is your catch can connected to the turbo side of the rocker cover only, or also to the side facing the inlet manifold?
The breather opening at the inlet manifold has a small check valve in it, making the opening about 6mm effective diameter, instead of 10-12mm which is possible if you remove it.
Here's a picture of my setup. I use 8-an lines, but reccoment others to go for 10-an as I still struggle a bit with crankcase pressure.
yea mine is redtop with the t piece at the exhaust side.so i came outta the crankcase into the t piece then outta the other side and into the catch can.that sound right?you're not on wot all the time. the crankcase will be evacuated between gear shifts the normal way. there will be a small draw through the turbo on boost, which is what causes the ic and pipework to get coated with a film of oil. using my amazing mspaint skillz i've drawn a diagram to illustrate the normal scavenging flow of crankcase fumes on the blacktop bentcam
the redtop is slightly different as it has a t-piece on the front exhaust side cam cover from the crankcase instead of the direct feed to the rear
catch can should be on the outlet on the inlet side of the cam cover. ideally it should go:
cam cover > catch can > pcv valve > inlet manifold
the side with the t-piece should be left alone
i've seen it done every other way under the sun, but this is the best method imo.
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