at 500 miles it was #7, and at 1200 miles it was #4. You're not listening to me on the surfaces. 1st time, bad seal, 2nd time picture perfect
groucho is the car by chance equipped with a 350 or 400 trans if so your fouling could be caused by the modulator being ruptured and being pulled into half your plenum at the rear manifold runner .
then its coming from the topside. i completely understand your frustration. you may have a crack in the head around the rocker stud, the valve guides may be leaking even if they are brand new heads. a buddy of mine built a big block chevy recived brand new heads from trickflow and the valve guides were already bad and it was pulling oil into the blower. pull the valve covers and inspect the heads around the rocker studs for cracks. if its not coming from the bottom side and the valve seals and guides are good like you say thast the only other thing i can think of.
That still doesn't explain the VOLUMES of oil uphill from the area you suggest. Look at the picture. That's after a 20 mile drive on the freeway with fresh fuel/air washing the plenum. Yet still the volume. Plus, only one side
What kind of valve guide seals are you using? Is it possible that one of the seals has been torn down one side or has a chunk missing out of it that allows the oil to flow past? I don't know if I'm in the right area, or if I'm just shooting in the dark here, but I'm looking at other possibilities. I've seen some funky things happen that defy explanation. This could show up as a strong seal with the pressure test, but when pulling downward with the valve it could be creating the leak. Is it possible?
Like I said, I'm guessing and shooting blind here. What about checking compression after the motor is at operating temperature - mainly just that one cylinder? Don't bite the messenger - damnit! {[]
Just asking if you saw the pic. I did a leakdown instead of comp check. Also it's different cylinders each time
my truck pulls oil into the throttle body from the plenum pan and up 12 inches of intake runners. its a small block fuel injected mopar, but the intake vacuum will be the same. i understand how frustrating this is for you. clearly after a closer look at the gaskets the oil is coming from above the valves. so your looking at a problem in the heads, the only thing oil flows to thats that high. the only way it can get into the chambers is past a vlave, the only way past a valve is a bad valve seal or guide. also you may have a crack in the head, usually they crack from around the rocker arm stud. its possible for a vacuum to pull oil up that high. the only thing higher than the spot where the oil is is the carb and air cleaner. vacuum will pull an object as far as it will go until its met with a positive pressure, at which point it will push it back into the cylinders or pool in the intake plenum. so dont rule out the fact that large volumes of oil could be pulled upward like that , its just like pulling oil through the PCV its the highes point in the system yet it can still pull oil like crazy. A vacuum will pull until it equalizes pressure with air a soild a liquid whatever. so it will pull oil into the intake until it displaces enough air to create an equal pressure. that may be 1oz or 1 qt of oil. just like a shop vac the more crap you suck up the less sucking power it will have until it has displaced more air than it needs to move to make vacuum. i know all motors are different but physics never changes.
You state the only way oil can get past a valve is through the guide? What if it's already in the air/fuel mix from a porous intake sucking from the lifter area? You guys need to get more creative. I need more imagination here. I've covered the "basics".
the only way i would think of it getting that high into the intake would be either a cracked intake or throught the carb (vacuum port, maybe advance line).
that was actually a common problem on chevrolet big blocks used back in the early 70's, mostly in intakes and cylinder heads. the cast pieces werent built as strong and were very porous, but they were built that way so the lead in the fuel would seal the pours. one of Gms good ideas that went to pot when unleaded fuel started being used. im not completley ruleing the fact that the intake may be pourous and sucking oil. but i think that if it were porous it would be caused by a casting issue. usually poor metal guality or problems during the cooling process. i would think that the whole intake would be that way and not just one half of it. But then agian alot of weird things happen, metal can be ver unpredictable. send it back if you think thats the problem, or find another on somebody has laying around for you to use temporarily. swap it out and see if it still happens. hopefully you get this one figured out, something somewhere isnt adding up.
definitley report what the fix is! I don't see how oil can get in the manifold unless its not sealed along the bottom of the intake and its getting sucked in from the lifter valley and then just being turned into a mist saturating the entire inside of the one side of the manifold since the pcv is dry, does the holley 3310 have a metering block? if so maybe oil is getting sucked in thru a vacuum line hooked to the one side of the carb?
No vacuum lines to the carb. Just vacuum/hideaway headlite vacuum to intake runner. No oil bearing accessories
No vacuum lines to the carb. Just vacuum/hideaway headlite vacuum to intake runner. No oil bearing accessories no vac. lines to the carb.? where are you getting vac. for the distributor advance ? 4 speed..so that rules out an auto. trans modulator possibly letting trans fluid get sucked up into the carb via carb vacuum. besides that, it is motor oil, not trans fluid that you are seeing. good intake to head seal, as visible by the pics of the gaskets. no oil being sucked through the pcv valve....but, if you have no vac. lines to the carb....where is your pcv valve getting it's vacuum from ? my first guess was a valve guide seal...but that doesn't necessarliy explain the fouling of different plugs at different times. but then again, if oil is being sucked up into the intake from one valve guide seal, once it's there it can be dispursed throughout all of the cylinders. the oil in the intake is puzzling. you would think that any oil that is accumulating on the floor of the intake would be sucked into the cylinders. (which some of it is...hence the fouled plugs) in this case it appears that the oil is being pushed back into the intake from somewhere. this is just a guess.....if the heads have been milled this would throw off the angle of the intake to head mounting surface.(you never mentioned milled heads tho). but maybe, just maybe the mating surfaces of the intake, and the heads or slightly off due to a casting flaw in either the heads, or the intake...and the oil is coming from there ? the angles may be close enough to show a good gasket seal visibly (on the intake gaskets) but it doesn't take much space to let oil get sucked into the intake from the lifter valley. this is a tricky one, and i want to know what you find...who knows. maybe it's something simple, that non of us would ever think of..
Groucho - I know you don't believe it, but it really does look like valve guide seal leakage to me. Remember - the entire intake tract is under vacuum, and the 'flow' towards each individual port occurs only one quarter of the combustion cycle - the other three-quarters of the time the oil would be pulled into the tract and distributed wherever it wanted to go. The manifold will most likely be fine - if there was a flaw, the fouling you've experienced would not migrate from hole to hole.
Sure it would.....the same way you just described with a leaking valve guide.... Mech advance I'm sure......all the fast cars run it.....hehehe
This in response to the last 3 posts. Yes, mechanical advance only. Yes, the PCV to carb. I said no vac lines to carb because the PCV was already covered several times. That's a LOT OF OIL for a brand new set of heads with upgraded valve guide seals that I added after the 1st fouling. I know it's tedious, but you have to read all posts. I know about the 4 cycle thing. But, put your hand over the throat of a carb while a motor's running, and there's a helluva strong pull all the time for that much oil to remain in the intake floor after a 20 mile trip on the freeway. Hell, look how MINT the other side of the intake appears. There's a REAL problem somewhere, and it's only on half the intake
Are the heads bone stock? It seams to me that the moving around of the oiled plug would point to a common part - and since it jumped sides from 7 to 4, the only common part I can think of is the intake. Especially since you say the PCV is dry, and the gaskets are sealing. I had an m1 intake on a SBM with heavily ported heads and it did the exact same thing - sucked oil up into the intake (and only with 10" of vacumn) and oil fouled 1 plug. The problem was a cracked intake port. But it always fouled the same plug first.
That intake has an exhaust crossover, No? and it's the "bottom" runner packe on a dual plane? I betcha that it's cracked INSIDE of the exhaust crossover (heat riser) area, and it's pulling vaccum because your heads have the exhaust crossovers blocked off. if you had not just sent it off to edelbrock, I would say tap the hole in the underside of the intake (which I honestly have no idea what it's there for) and plug it. but you're right...if it were from the valve stem side, it would stay closer to the valve itself. Once in the runner, the air doesn't deviate from it's path too much-easily proven by how certian cylinders are "leaner" than others on any given engine. (sbc-1 and 8, typically.) I bet it's in the intake.
That's what i'm thinking/hoping for. Nothing else is logical. There's one post about the 4 cycle thing, and a cylinder's not always pulling. They're forgetting TWO things. ONE-on a mild cam, when the cylinder's not pulling, the intake valve's shut. TWO-there are EIGHT cylinders. Pretty much full time sucking at the plenum. So, how's that much oil getting uphill against all those factors unless it's the point of origin. Also,the intake is the highest concentration of oil. If it were coming from somewhere else, it would be heaviest at that somewhere else, and thinning out at the plenum.
hopefully its just an intake problem and nothing else. what makes me so leary as to why it wouldnt be that is alot of oil for a 20 mile run to be absorbed by the intake due to porosity. also the intake would lose vacuum as the intake temp increase and a crack expanded. I really do hope its the intake and they send you a new one that would be so much easier. RacerRick- happens all the time with mopars especially with ported heads, but usually on stock style manifolds. the M1 was a good choice though but thats kinda a flukey thing that it happened, is the motor a LA series? they also have problems with porting the heads and them leaking oil becasue the pushrods pass so closely to the ports too much of a porting job microfractures them during heating.
Well, it's more than 20 miles. My point was that it was just fresh off the freeway in case someone jumped to a "reversion" theory. Something that happens with big, long overlap cams in traffic. That was my reference to the 20 miles. Not that all that accumulated in that short time. As fas as vacuum? The oil oozing over time will seal the porousity from being an actual vacuum leak. It'll be just slowly pulling oil through the pores and not air. Make sense? It's a weird one for sure
I had a small block 400 that sucked oil if you got above 80 miles per hour. If you did 55 (the then aproved speed limit) it used no oil at all. I was pulling my hair out cause the pvc valve was changed etc and it would not use a drop till I would get on the interstate between Oregon and Washingto at around 80 miles per hour. It was a combination of the pvc valve and a crack in the intake manifold. As it heated and the crankcase pressure increased it would suck oil out of the crack under the carb in the valley. I sold the car like that and when the guy wrecked it the junk yard man found the crack. Might check the bottom of the manifold for cracks.
this would be a great time for one of those fiber optic scope thingies I almost keep walking off the "spensive" truck with. although about the best in the business, I can imagine Edelbrock gets a couple intakes back with casting flaws internally. I mean, sheer volume says every once in a while you are gonna have a lemon or two. Bright side...mabey you'll get some groovy edelbrock shwag out of the deal.
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