Oil pooling in intake due to Valve Guides???

[vristang]

Been driving the motor in the sig below. Pulled into the garage to do some tuning and pulled the intake tube. I found a huge puddle of oil on the outside of the TB plate.
Relevant info
The oil does not does not come from the oil filler vent hose as this hose is bone dry after installing a baffle in the valve cover. I the plug for #1 which was oily, and got 6% on the leakdown test (by this time the engine had cooled down quite a bit). The PCV valve is brand new.

Right now the plan is to have the heads looked over on Friday (I finally have a good excuse to use some of my sick leave!!!). Barring the PCV, valve guides are the only route for oil to enter the intake that I can think of. With 6% leakdown the PCV should be just fine.

But, I don't fully understand how valve guides can cause oil to pool at the TB. Could it have to do with the short runners and box intake? What engine conditions could cause this? Is there another possibility for the source of my problems?

I just rebuilt the motor for this problem, but had assumed it was caused by the 20% leakdown from low tension rings.
Assumptions

 

[stang22]

Are you sure that oil is not shooting up through the PCV valve? If you are positive it isn't coming from the vent hose off of the valve covers, that only leaves one other way it can come in.

Tim

 

[vristang]

I would love to convince myself that it is coming in through the PCV, but it just doesn't make sense to me.

There is relatively little blowby to push anything out of the crankcase, but I have to admit that I have no idea what kind of vac I am getting. There is a baffle on the underside of the intake as well. I just can't envision how this much oil is getting through the PCV. If it is the PCV then this is the second defective PCV I have purchased in a row. While I often doubt the quality of Fram products, and do so openly, I don't think this is likely.

Maybe someone has had a bad PCV experience similar to this? Maybe I just need a little convincing?

 

[stang22]

If you have blow-by or pressure, the best PCV valve isn't going to do you any good. Try placing a small filter inline with the PCV hose and see how much, if any, you are collecting. Read Michael Yount's write-up as well. Hope this helps.

Tim

http://www.leemotorsports.com/myount/cpcv.htm

 

[vristang]

If you have blow-by or pressure, the best PCV valve isn't going to do you any good. Try placing a small filter inline with the PCV hose and see how much, if any, you are collecting. Read Michael Yount's write-up as well. Hope this helps.

Tim

http://www.leemotorsports.com/myount/cpcv.htm

First off thanks for the response, I sure can use the help.

I read the first few pages of that site. Problem is I can eliminate each of the 4 items Michael lists as causes of problems with the PCV system.

1 & 2) I am using a Lightning lower intake. The Ford baffling is still in place. I did not have this problem when running this intake on the tired old used 351w I ran (with its stock heads and excessive blowby).

3) The motor is freshly rebuilt using gapless top rings from TotalSeal. I did a leakdown check and had only 6%. When I did this the motor had been sitting for several hours, and was quite cool. Blow by is probably not my problem.

4) Since installing a baffle in the valve cover, the hose between the filler neck and the TB has been bone dry. There is no oil entering the intake via this route.

Because of the above 4 items I do not believe the problem is due to a faulty PCV system. Regardless, I will pull the PCV hose and check it for oil. If it is dry the problem is definitely elsewhere. If it is saturated with oil, I will let the car run with the hose disconnected. Hopefully I will see large amounts of oil spraying from the PCV?

What could still be an issue?
1) I could have such a strong engine vac that it is actively pulling excessive amounts of fumes and oil out of the crankcase. This could be due to the increased displacement of the stroker, and the use of gapless rings? I think this is a far reach though.

2) The oil could be entering the intake via the valve guides. I am told that as the valve guides wear, the valves can no longer seat properly. What this would give me is oil being able to drip through the worn guide, and possibly combustion/exhaust gasses being pushed out of the cylinder and into the intake (carrying large amounts of oil with it). Right now I think this is the most likely answer.

3) I can't come up with anything else.

If I am way off base in my line of thinking please let me know. I just can't see how the PCV is the source of my problems.

 

[mcclean]

the guides very well could be worn. What kind of valve seals are you using? I ported a set of E7's and put umbrella seals on. The car burned oil and I had oil everywhere inside the intake (upper and lower, and by throttle body). I took the umbrella seals off and replaced them with rubber positive type seals. Problem solved. The guides were probably worn too much but this definitely took care of the problem. If you are running telfon positives this could also be part of the reason. I've never had luck with the teflons.

Brian

 

[vristang]

Holy Revival Batman!

I have determined that the problem was in fact the pcv. Currently I am using a small seperator to help pull some of the oil out.

I will keep the valve guides in mind though.

thanks,
jason

 

[rod196202]

relocate your pcv prob solved

 

[stang22]

Holy Revival Batman!

I have determined that the problem was in fact the pcv. Currently I am using a small seperator to help pull some of the oil out.

Tim