What could be causing my oil blow by?

[2toneNV]

I have a stock 109 block.

Mods: Roller cam, Champion Iron heads and intake, Precision plenum with RJC power plate, poston headers, ATR crossover, Hooker 2.5" dual exhaust, 3.5" DP with dump, PT&E 67mm DBB turbo, FAST XFI.

Problem: I have what I would consider excessive blowby. My builder installed a "really trick" catch can in-line with the PCV and I have since installed a check valve from Jack Cotton. The car doesn't get driven a lot and not very hard since the Nitto DR can't keep the car from hitting the rev limiter everytime I get into it more than 50%!?!:tongue:

I have the Champion valve covers on the car but for some reason we cannot figure out why the blowby cannot be resolved. I had the car back out of the garage on Thursday to let it idle to operating temp and as soon as it got a little warm I noticed smoke on the drivers side. I started looking and noticed the space around the rear drivers side plug was covered with oil and the VC breather saturated with oil. From the few times the car has been driven the drivers side VC, header, plug wires and Power Master are covered in oil.

What could possibly STILL be causing this amount of blowby ?
Any insight is MUCH appreciated.

FWIW: The Champion intake did not mate up flush with the intake side of the heads and my builder (Discostu) had the intake machined down to match. Other than that, I know Discostu is a badass when it comes to Buicks and I have complete faith in him. This is just sort of a pain.

 

[1chance]

Not sure if this help's, but i had alot blow by to, and i took and installed a vacum break that come on cars with vacum breaks, and put it on before my PVC valve, it needed help, and it helped alot, good luck.

 

[2toneNV]

Just so I understand what you are saying: You switched over to a vacuum brake set-up and that fixed your engine oil blow-by issue?

 

[bison]

If your making any power you will have some blow by. Cyl pressure=power=blow by. The more pressure the more blow by.

 

[turbodave231]

Have someone perform a cylinder leakdown test.......not a compression test!

The leakdown test will determine how well the piston rings are sealing. When you have that answer, you can better determine what to do next.

If you have excessive blowby, the crankcase pressure is coming from combustion gasses that are escaping past the rings.

Was this engine recently bored/honed? Did the rings have enough time to seat? Improper honing will affect ring seating/seal. Wear on cylinder walls and bore geometry (roundness) will also affect ring seal.

You should not have excessive blowby regardless of boost level and power output. An intake leak will not cause blowby (crankcase pressure) without other major driveabilty problems.

Dave

 

[vacuum 6]

Why the Champion valve covers?

 

[Chuck Leeper]

"I had the car back out of the garage on Thursday to let it idle to operating temp and as soon as it got a little warm I noticed smoke on the drivers side. I started looking and noticed the space around the rear drivers side plug was covered with oil and the VC breather saturated with oil."

Puking oil while idling = serious lack of crankcase venting, or some messed up parts.
I'd be looking at the catch can/pcv install, first..Along w/ the leak test, that's been mentioned.

 

[TurboBuRick]

Are you sure the pcv check valve is intalled correctly? If it's backwards it will not let the pcv work.

 

[xcessiv6]

I get blow by made my own catch system with summit pcv valves and catch can, I have the champion valve covers and the hole in the valve cover is close to my roller rocker were the oil comes out, the steam is normal when the car heats up's on mine, the amount of moisture and oil residual is in conjuction with how much your in the boost. Last year I saw Dave Fiscus at the track and he would get alot of oil in his system on every pass and have to empty it. I take as normal on a modded motor.

 

[TurboBuRick]

I get blow by made my own catch system with summit pcv valves and catch can, I have the champion valve covers and the hole in the valve cover is close to my roller rocker were the oil comes out, the steam is normal when the car heats up's on mine, the amount of moisture and oil residual is in conjuction with how much your in the boost. Last year I saw Dave Fiscus at the track and he would get alot of oil in his system on every pass and have to empty it. I take as normal on a modded motor.

No, it's not normal.

 

[Chuck Leeper]

"Last year I saw Dave Fiscus at the track and he would get alot of oil in his system on every pass and have to empty it."

Yep! At 40# boost, strange things happen!!

 

[TR Custom Parts]

Are you sure the pcv check valve is intalled correctly? If it's backwards it will not let the pcv work.

Sounds like a good possibility there!

 

[vacuum 6]

Do you need the Champion covers? If not, put the stock ones back on and see if the issue goes away.

Have you raced the car, is it making good power?

 

[2toneNV]

I thought that maybe the check valve was installed incorrectly, but that is why I checked and triple checked the direction. As for the catch can, it is being used on several other Buicks with NO problem (piece made by TKGN1). As for the valve covers, I picked them up for looks but need them now with the T&D roller rockers.

As for power: the car makes Big Power but not as much as it could because Boost is set at around 22psi max because I don't want to hurt the motor and its stock bottom end.

 

[JDSfastGN]

Double check the check valve. Mine was preassembled from Kirbans incorrectly and I had a bit of smoke out of the breathers until i reversed it.

BTW Why is it hitting the rev limiter at more than 50% throttle? There really shouldn't be a limiter since you are using alky unless its cutting ignition instead of fuel like a stock ECM. And I set up the tranny to shift at 54-5500 at WOT so it shouldn't come close to the limiter??

 

[TurboBuRick]

If it's not coming through the pcv then you are looking at either a blown hg or some type of issue with the rings. It's pretty cut and dry.

 

[jdpolzin]

What did you find out about this problem?

One quick question, do our rings move around the piston while in the motor? Or are they going to pretty much set on the exact place where the builder installed them too?

Could it be possible that Stu didnt set the rings at the correct direction and the the gaps in the rings have possibly lined up with each other, creating a void for pressure to leak?

 

[disco stu]

I performed a leakdown and compression to make sure that all the work we were foing to do was going on a good base to start with. I don't remember exactly what the numbers were, but I remember them being even and leakdown being stellar.

Still, 20+ on a 25 year old motor will push some combustion through the ring gap.


Try the tall breather stands, Craig. Maybe in conjunction with the baffled grommets (usually available at parts stores).

 

[qwks6]

I'd re-check the pcv, make sure it's all hooked up right. I had regular vacuum line hooked up to mine and it pinched not allowing a proper vent. Make sure it's fuel line or something along those lines so it won't pinch.

That's all I've got

 

[$uckin6]

if the the person who assembled the motor forgot to put back the windage tray or what ever that tray that sits in the valley of the block under the manifold is called, would that cause excessive oil to be sucked in to the pcv not saying just asking