austincrx

AP1's burn oil under hard right-hand corners where oil sloshes into the breather tubes and is sucked through the intake. As best I can tell everyone just uses a catch can setup for this, but that isn't a real solution. The question here shouldn't be 'How do I get the oil to not enter the intake pathway?' The real question should be 'How do I get the oil to not slosh out of the cylinder head?'

Has anyone looked into this? Perhaps creating some sort of baffling inside the valve cover to prevent oil sloshing, or even some type of seperator that will keep the oil from moving all the way through the tubing and into teh intake pathway.

One more interesting issue is which pathway is actually responsible for 'sucking' the oil into the air intake pathway? The PCV is a one-way valve, perhaps there is an application for another pcv valve location between the valve cover and the intake tube (pre-throttle body)?


Just trying to figure this out because adding a catch can just seems like a 'quick fix' that is only acting to cover up the real problem.

iamxpl

People have drilled the baffle plate in the valve cover. That is the known source where the oil pools and then gets into the breather tube. Some people just cap off that tube and be done with it.

nos4you

Id like to know also. I have the same problem with my05. I'm planning on a catchcan too but if there is a way to avoid it that would be great. I'm also planning on drilling the valve cover but havnt done it yet.

s2000maniac

I thought the AP2 valve cover fixed this issued with the newer PCV design?

austincrx

I think it's primarily the AP1's, but maybe the first few years of AP2's didn't have the updated valve cover? I recently attended a track day that had 3 ap1's and 2 ap2's (1 was a CR), and the only car that didn't smoke around one or all of the hard right-hand corners was the CR.

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So I am curious, is there a 'shelf' type thing inside the valve cover where the oil pools? I'm just trying to picture in my head how it would be beneficial to drill a hole. I'm guessing that the breather tube port is on top of the 'shelf' and the oil just flows into the port when you turn right? In my mind that's what I'm picturing.
What other issues will having that hole there cause?
Does anyone know how the AP2 valve cover is different (baffling) from the AP1?

afzan

There are 3 types of valve covers

00-03 with ap1 pcv
04-05 with ap2 pcv
06-09 with ap2 pcv

Only 00-05 are interchangeable (assuming you use the appropriate pcv). If you search around on here, some people have drilled holes in the baffling in the valve cover to solve the issue. Other people just clamp the pcv hose when they are at the track

austincrx

That is interesting because I just read something about the vent to the air intake tube being what caused the majority of the oil burning. But my real issue is this: I am planning (in the next two-three years) to do some amateur endurance racing with my S (caging it and all other safety equipment later this year, then testing most of next year/getting it competitive), and from what I hear and have found on my own, the S burns about 3/4 of a quart of oil per hour of hard racing. Does anyone make a catch-can that is over 1 quart? I am going to drill the valve cover first, and hopefully this will solve the problem, but I'm asking incase it doesn't completely fix the problem.

Thanks! the information you all have provided has been very helpful.

austincrx

I'm resurrecting this thread so I don't start a new one on the same topic.

A little info: 2002 S2000, only engine mod is Brian Crower dual valve springs and steel retainers. Car runs squared Kumho Ecsta XS tires from 2008, a large custom front swaybar, and a custom rear spoiler.


After doing a track day with 3 hard right hand corners (all 180degrees or more!), and my valve cover baffle 'punched with holes,' I discovered a few things:

1) My first setup was as follows: Tube routed from front valve cover vent to Catch can, second tube from CC to overflow tank, which was vented to the atmosphere. A cap was placed on the PCV, a cap on the intake manifold PCV opening, and a cap on the intake tube vent pipe.
I ran this setup for a 20 minute session and noticed an oil burning smell. I came in and found that valve cover pressure had popped the dipstick out of the valve cover and that oil was coming out from around the PCV in the valve cover. There was enough oil coming out to leave a sufficient puddle on the ground when I parked the car after the session, there was also a good bit of oil to clean up that had come from the PCV valve cover seal.

2) I then changed the CC tube to vent the PCV from the valve cover, and left the overflow tank connected to the CC like the first setup. I capped the valve cover vent, left the intake tube and intake manifold capped, and checked the oil. Oddly enough the oil level was still at the 'full' mark on the dipstick (when oil heats up it expands more than you might think, I've personally seen a 33% expansion before, 3 quarts expanded to 4 quarts in an ;85 Honda civic race car), so I didn't add any engine oil, and there was no oil in the catch can, at least not enough to matter.
I ran a 20 minute session like this and came back in to find 1/4 of a quart in the CC. Not too bad, but I wanted to have NO oil in the CC. I decided to leave the oil in the CC and see what happened in the next session. Oil was still at 'full' oddly, so I didn't add any.
I ran a 30 minute session with CC setup 2 and had to stop after about 15 min. because the car went to 4 bars temperature reading! I actually saw it jump, so I lifted, ran it relatively lightly, and after 20 seconds it went back to 3. I pitted and checked the oil level. It wasn't especially low, maybe 1/8 of a quart according to the dipstick, but I had a full 1/2 quart in the catch can. I added 1/2 quart to the engine oil, drained the CC, and waited for the next session.
Another 30 minute session and I had no temperature issues, but had a full CC (1/2 quart) when I was finished, as well as a small amount in the overflow. This was the last session, so I couldn't try anything else.


Future setup: I plan to modify the valve cover baffle even more because I have only punched holes, not drilled them. This means the holes are not as effective because they have small protrusions sticking upwards, impeding the flow of oil through them. But if I can get in the holes with a tool and flatten the holes out, or have the pieces protrude downwards, then this may solve the issue all together.

I'll post pictures eventually.

nissanfanatic

I capped all PCV ports except for the front, which I put a breather filter on from the ricer section at Advance auto parts.

It showed no adverse effects in my UOA.

S2Krazy89

I was looking into solving the same issue. My plans were to just reroute the oil back to the pan.