blowing oil out the valve cover breather ports

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12-05-2010, 09:31 PM

#21

mighty mouse

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Quote:

Originally Posted by 18psi

Yeah 220 is pretty darn high IMO, but I've seen 205 before on a very healthy engine.

Don't know.

I can't vouch for the accuracy of the gauge, maybe I'll get another one and run the test again.

12-05-2010, 09:56 PM

#22

Faeflora

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Quote:

Originally Posted by Doppelgänger

Oh **** it. Fill both holes and put fittings on TOP of the baffles...coming straight up out of the VC. That should sove any sloshing problems

Sure why not, that would work. Boner.

OP---- do you still have the baffles in your valve cover? Hustlyer is filling up his can under different driving conditions-track vs. street.

12-05-2010, 09:56 PM

#23

hellaUNflush

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Quote:

Originally Posted by faeflora

Sure why not, that would work. Boner.

OP---- do you still have the baffles in your valve cover? Hustlyer is filling up his can under different driving conditions-track vs. street.

Hustler still has his baffles in correct?

12-05-2010, 09:58 PM

#24

mighty mouse

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Mine are in place, yes

12-05-2010, 10:02 PM

#25

Faeflora

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Oil pump shimmed like mad making mad oil boost? What does your oil pressure gauge say

12-05-2010, 11:54 PM

#26

mighty mouse

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Quote:

Originally Posted by faeflora

Oil pump shimmed like mad making mad oil boost? What does your oil pressure gauge say

it seems to be reading normal to me- 15psi or so at warm idle, 30psi cruising around 2.5-3k RPM. On cold starts it goes up to like 60.

I'm running those boundary engineering oil pump gears as well.

12-05-2010, 11:57 PM

#27

hustler

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Quote:

Originally Posted by hellaUNflush

What kind of can are you using? Which line going to the catch can did you delete, the PCV line?

Jeg's house brand, only running a -10 port on the driver's side of the valve cover, PCV plugged.

02-10-2011, 01:32 PM

#28

JR4WDTRBO

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Rez-erected: I had this issue with my GTX. Turned out to be a PCV valve not doing its job under boost and the baffles need to be resealed. Pull the valve cover, clean the heck out of it, pull the baffle covers, clean and reseal with RTV.

02-10-2011, 01:44 PM

#29

Braineack

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that's why i simply run a check valve before the PCV.

02-10-2011, 01:52 PM

#30

mighty mouse

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Quote:

Originally Posted by JR4WDTRBO

Yeah I'm in the process of redoing my catch can setup, and will be going through the VC again in the process. Thanks for the tip

02-10-2011, 09:16 PM

#31

sawjai526

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In for results, please post when you figure it out!

02-15-2011, 09:22 PM

#32

drewtam

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Stock MSM PCV/catchcan is also troublesome. Some cars pass enough oil to cause ping. Many rig up VTA systems.

02-15-2011, 09:49 PM

#33

Faeflora

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Quote:

Originally Posted by drewtam

Stock MSM PCV/catchcan is also troublesome. Some cars pass enough oil to cause ping. Many rig up VTA systems.

My car stopped detonating when I took my breather and PCV to VTA instead of the intake.

02-16-2011, 01:36 PM

#34

sixshooter

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Quote:

Originally Posted by Faeflora

My car stopped detonating when I took my breather and PCV to VTA instead of the intake.

Oil has a much lower octane rating than pump gasoline. Engines that burn oil detonate more easily.

02-18-2011, 08:16 AM

#35

wildo

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Has anyone seen this problem on a naturally-aspirated engine?

My leak-down and compression numbers are spot-on.

Blow-by in the crank case (measured from the dip stick) and valve cover (measured from a fitting on the oil cap) are less than 1" of water at idle, and about 0 at WOT (did this in the shop while parked - so no load on the engine).

Engine is 11.5:1 with 8500 RPM redline.

Engine is freshly-built with one track day under its belt. PCV port and breather port both run to an oil separator which drains back to the block via a check-valve. Separator vents to atmo. Oil was puking out of the vent while turning laps.

I thought blowby had to be present for oil to puke?

02-18-2011, 10:22 AM

#36

sixshooter

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No load is a lot less cylinder pressure than full load. Maybe that is a factor?

Could oil slosh be a problem up in the valve cover? Are you running oil restrictors to keep the top end from over oiling at 8500rpm? That might help. Smoothing and opening up the drain holes in the head might help as well. Unfortunately, the head relies on gravity to drain all of that oil and hard cornering coupled with an overabundant supply can be trouble for that process. If you are running a high volume pump it can exacerbate the issue, too.

02-18-2011, 10:40 AM

#37

wildo

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Quote:

Originally Posted by sixshooter

No load is a lot less cylinder pressure than full load. Maybe that is a factor?

That is what I'm wondering, too. I'll have the car back to the steady-state dyno within a few days to test the car under sustained load at high RPMs and see what happens.

Quote:

Could oil slosh be a problem up in the valve cover?

That is what I have been thinking all along, but I recently spoke to an EP engine builder/racer, and he's never experienced that problem on his engines.

Quote:

Are you running oil restrictors to keep the top end from over oiling at 8500rpm? That might help.

Yes, I'm running the stock restrictor.

Quote:

Smoothing and opening up the drain holes in the head might help as well. Unfortunately, the head relies on gravity to drain all of that oil and hard cornering coupled with an overabundant supply can be trouble for that process. If you are running a high volume pump it can exacerbate the issue, too.

Thanks for the post & info. I was fine with believing that the problem was due to oil slosh, until I recently spoke to the EP engine builder and he said that he's never seen that happen before due to slosh.

02-23-2011, 10:28 PM

#38

drewtam

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My experience on some engines is that no load and light load can be worse for blowby and oil consumption than full load. The reason is that compression rings are designed to use the cylinder pressure. The pressure gets behind the ring (between the piston cut out and the ring) and pushes the ring outward against the cylinder wall.

If there is not enough cylinder pressure (no load and light load), the ring pack can fail to seat and seal completely.