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Re: where is my oil going?
[Re: moper]
#557988
12/21/09 01:21 PM
12/21/09 01:21 PM
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Joined: Jul 2006
Posts: 4,179
California
mickm
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OP
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Quote:
The rings need a smooth finish to seat properly and they will show less than 4% leakdown if they have. IMO, yours haven't.
i kind of figured that, but will have to deal with that at another time.
Quote:
If you disconnected the PCV and drove it for 50 miles you should see no drop in oil level if it's sucking past the valve. I dont think it is.
if it's sucking past the PCV, then i should see a drop in oil use, is that what you mean? if it's the rings, then obviously that won't help, but at least i eliminate this as a source.
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Re: where is my oil going?
[Re: mickm]
#557989
12/21/09 07:34 PM
12/21/09 07:34 PM
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Joined: Nov 2003
Posts: 2,715
closer to Canadian beer!
torkrules
I'm neurotic
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I'm neurotic
Joined: Nov 2003
Posts: 2,715
closer to Canadian beer!
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Quote:
my engine still uses a lot of oil, quart or so every 100+ miles. haven't checked it exactly, but it's a lot.
brief history. after i got it took the heads off, and found that the intake was very loose and sucking oil. it was bad, the gaskets were wet along the bottom for all the ports. thought i found the problem, all else looked in good shape, so just did a re-gasket, (and cam, new intake), and put it back together. better, but still sucked oil.
leak down showed 8-10% for all cylinders, compression test good, (forget the numbers, but all very close). was sure it was the guides/seals. took the heads off again for this reason, (but also to have them ported), and found it was again leaking through the intake, (i didn't know these had to be sealed with gunk).
so here i am now.
- guides were fine, new seals.
- sealed intake.
- cylinder walls looked good, nice crosshatch still visible.
- plugs do not show signs of oil consumption, (maybe very minor, but i have nice tan insulators, with the slightest bit of soot around the rim, don't know if it's oil or slightly rich mixture).
- leak down and compression tests were a few thousand miles ago, so things could have changed.
- q-tip in pcv port at carb came out grayish, but certainly not what i would expect if it was sucking that much oil through there.
does blow a little blue smoke when starting it up after cold and sitting for a while, but not bad.
if i have been driving normal for a bit, and then nail it, it does blow a big one time puff of smoke out the back, but it's hard to tell the color from looking back. seems that clearing that once or twice is fine, then no more smoke on nailing it.
does not seem to smoke any other times but those two.
so where do i go from here? is it possible that my oil rings are in that bad a shape? engine probably has 6-7k miles on it.
Jeez, that sounds like what mine used to do. I was loosing a quart every 500 miles. At the time i had two problems:
Loose guides thanks to who ever machined the MP aluminum heads.
Too much piston to wall clearance again thanks to who ever honed the block (crate engine).
The big tell tail was oil in the tail pipe. The intake is major problem. Which gaskets are you using? Are they the thin ones? The Mister Gasket pieces are solid right accross and less likely to get sucked in. I know Tim uses the right stuff around the parts. I found the Hylomar blue works great It stays flexible and is not effected by fuel.
Have you checked the guides. The only way to really check this properly is to pull a valve spring and lower the valve slightly and wiggle it around. It may have a slight movement but if it moves alot, the guide is bad.
Mine leak around the breather tubes as well. Do you have the 70 and up covers or the 69 and down covers?
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Re: where is my oil going?
[Re: mickm]
#557992
12/22/09 12:35 PM
12/22/09 12:35 PM
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Joined: Feb 2003
Posts: 12,675
Columbia, CT
moper
I Live Here
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I Live Here
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Posts: 12,675
Columbia, CT
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Quote:
i kind of figured that, but will have to deal with that at another time.
If it's the issue, you may be dealing with it sooner 
Quote:
if it's sucking past the PCV, then i should see a drop in oil use, is that what you mean? if it's the rings, then obviously that won't help, but at least i eliminate this as a source.
That is what I meant, yes. Try to isolate and remove the possibile causes one at a time. Breather, PCV, gasket leaks. The only real hard evidence you have is oil levels dropping an bad leakdown. Those alone are not enough to determine a cause.  Keep after it! 
Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.
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Post deleted by Defbob
[Re: torkrules]
#557993
12/22/09 12:55 PM
12/22/09 12:55 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Re: where is my oil going?
[Re: moper]
#557997
12/22/09 11:22 PM
12/22/09 11:22 PM
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Joined: Jul 2006
Posts: 4,179
California
mickm
OP
master
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OP
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Joined: Jul 2006
Posts: 4,179
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an attempt to answer all the latest questions: - alum mopar heads, older versions. - heads were recently done by a very reputable head guy. guides were fine, new seals. - 69 and down valve covers, inserts for the spark plug tubes in the heads - don't remember the intake gasket brand. intake with no gaskets had even distance all the way around between the heads and intake. with gasket in place, there was room to squish the gasket. no end seal gaskets, just used the right stuff to seal ends. sealed both sides of the gasket according to tim bannings instructions. - grandpa, i don't think i have the same issue, but wouldn't know with the intake on. i will have to look at a picture of the manifold and heads. i don't think i'm leaking at the intake. i had a cotton swab down in the port past where the intake seals, and it came up dry. a light grayish coloration on the swab. when i was leaking from the intake before, i could run my finger over it and come up almost dripping. i talked with tim at FHO, and he agreed, get rid of the PCV. i'm at least going to do that to see if it changes things. one thing i noticed about my PCV valve is it doesn't seem to shut off. the ball is loose and wiggles around, but when there is no vacuum on it it should be closed, and it isn't. this could be affecting things... i've got it disconnected, just need to get a breather, and will go from there. thanks for all the help everyone 
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Re: where is my oil going?
[Re: mickm]
#557998
12/23/09 08:20 AM
12/23/09 08:20 AM
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Joined: Nov 2003
Posts: 2,715
closer to Canadian beer!
torkrules
I'm neurotic
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I'm neurotic
Joined: Nov 2003
Posts: 2,715
closer to Canadian beer!
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Hey Mick,
The PVC is a controlled vacuum leak. At idle, vacuum is high (theoretically) and should keep the ball closed. When you mash the throttle, vacuum drops and the ball goes loose. This is where most of the blow by/crankcase pressurization occurs and forces this stuff up the valve covers and back into the intake. When the engine is off (no vacuum) the ball should rattle around.
Now, if your cam has alot of overlap which results in low vacuum, the ball may not close down acting as if you were at a wide throttle position. If you have a baffle under the valve cover, there should not be much oil going into the PCV. If there were, the hose should have oil in it as well as the intake. Also, where do you have the hose connected to? It should go on the carb. If you connect it to the intake, the nearest cylinders may go a little lean.
I know alot of guys just run two breathers and no PVC, but if it were me I'd like to have some sort of positive venting system for the crank case like an evacupan system (running two hoses to the headers and letting the exhaust gas create a small vacuum)
If your tail pipes are clean (no oily goo that looks like a two stroke), then I would suspect it's more likely an intake/head seal problem unless the oil rings/second ring fell out or you are using low tension oil rings. With as little miles that you have on it, I doubt it's a ring issue.
What was the piston to wall clearance? Has it been doing this since it was built or just started recently?
The 69 and under valve covers have unique issues since the breathers fit onto stacks (more of a problem for the PVC). Tony D'agustino sells a nice repo breather but they are about 100 bucks. You might find a Chivey breather the might fit but the PVC you'll need to find from a repo place. Mopar used to sell them but I find fewer and fewer parts are available from MP. And yes the stacks do seep oil. The thinner the oil, the worse it is.
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Re: where is my oil going?
[Re: torkrules]
#557999
12/23/09 08:51 AM
12/23/09 08:51 AM
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Joined: Feb 2003
Posts: 12,675
Columbia, CT
moper
I Live Here
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I Live Here
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Posts: 12,675
Columbia, CT
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Quote:
The PVC is a controlled vacuum leak. At idle, vacuum is high (theoretically) and should keep the ball closed. When you mash the throttle, vacuum drops and the ball goes loose. This is where most of the blow by/crankcase pressurization occurs and forces this stuff up the valve covers and back into the intake. When the engine is off (no vacuum) the ball should rattle around.
I think this is incorrect. The PCV is a controlled vacuum leak. However it is not held closed by vacuum. It's closed by pressure on the carb side that seats the check ball. That's to stop a backfire from going into the crankcase if memory serves right. Either vacuum from the carb, or pressure from the crankcase will un-seat the ball. The only reason to remove it is when there is very low idle vacuum or for cylinder to cylinder tuning(balancing). Breathers alone typically do not stay dry. The vapor condenses and fills the filter media in the breathers then runs out and gets blown all over.
Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.
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Re: where is my oil going?
[Re: moper]
#558000
12/23/09 02:12 PM
12/23/09 02:12 PM
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Joined: Jul 2006
Posts: 4,179
California
mickm
OP
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OP
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Joined: Jul 2006
Posts: 4,179
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well, all this is getting interesting. i'm hearing both sides of the story, that the PCV should be closed at idle, that it should be open at idle.
i think it is time for a little PCV theory investigation on my part.
here are things as they stand:
- i'm eliminating the PCV to see if that changes my oil consumption. i may put it back later, but for now i need to at least rule that aspect out.
- according to tim at FHO, just get rid of it.
- either way, i don't think my valve is working correctly, as it seems to not be able to fully close, and therefore restrict the air flow, (whether it is at idle or WOT).
- i just retuned the carbs after taking the PCV out, and i'm running 13" of vacuum at idle. more than enough to close that valve if it is supposed to be closed at idle.
- i don't know the piston to wall clearance. there are times when starting the engine cold that i hear some piston slap, so i'm sure i have issues there.
- pcv was connected to carb, not manifold.
will see what no PCV does, but i also need to determine if mine is working correctly. if it isn't, then once i see what happens with oil consumption, i will decide if i want to get one that is working and put it back on. i too like the idea of some additional help in ventilating the crankcase.
Last edited by mickm; 12/23/09 02:20 PM.
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Re: where is my oil going?
[Re: mickm]
#558002
12/23/09 02:37 PM
12/23/09 02:37 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
well, all this is getting interesting. i'm hearing both sides of the story, that the PCV should be closed at idle, that it should be open at idle.
i think it is time for a little PCV theory investigation on my part.
here are things as they stand:
- i'm eliminating the PCV to see if that changes my oil consumption. i may put it back later, but for now i need to at least rule that aspect out.
- according to tim at FHO, just get rid of it.
- either way, i don't think my valve is working correctly, as it seems to not be able to fully close, and therefore restrict the air flow, (whether it is at idle or WOT).
- i just retuned the carbs after taking the PCV out, and i'm running 13" of vacuum at idle. more than enough to close that valve if it is supposed to be closed at idle.
- i don't know the piston to wall clearance. there are times when starting the engine cold that i hear some piston slap, so i'm sure i have issues there.
- pcv was connected to carb, not manifold.
will see what no PCV does, but i also need to determine if mine is working correctly. if it isn't, then once i see what happens with oil consumption, i will decide if i want to get one that is working and put it back on. i too like the idea of some additional help in ventilating the crankcase.
A PCV doesnt close all the way... at idle it has a
small orfice that its pulling air... then as you
step on the gas the engine drops in vac and opens another
larger orfice
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Re: where is my oil going?
[Re: RodStRace]
#558004
12/23/09 03:36 PM
12/23/09 03:36 PM
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Joined: Jul 2006
Posts: 4,179
California
mickm
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Quote:
how with drawings
http://www.envalve.com/how.html
and this.
at idle and low vacuum it should be drawing the least amount of air through. makes sense, as that is when there should be the least amount of blow by in the crankcase.
mine was drawing so much at idle that it sucked my finger to the valve opening, and dramatically changed my idle. that plus the amount of oil around the outside of the filler tube tells me that most likely my valve is bad.
so again, first i will eliminate it completely, and then i will look for a replacement.
btw, anyone know where to find a replacement? local part store didn't seem to have anything...
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Re: where is my oil going?
[Re: mickm]
#558005
12/31/09 09:47 PM
12/31/09 09:47 PM
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Joined: Jul 2006
Posts: 4,179
California
mickm
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minor update. disconnected the pcv and put another breather on, (cheap mr. gasket). went driving to put some miles on it to see what's up. came back, and the breather is gone! blew the sucker right off! luckily, as far as i can see, it didn't damage anything, just fell off and rolled down the road i guess. it didn't fit as tightly as the other one, and i did wonder about it, but i decided it would probably be fine.  splattering of oil around the tube in the valve cover and the under side of the hood. what worries me more is that there is oil on the valve cover around the other breather. i really don't want to go with an evacuation pump. there are plenty of big inch motors out there, i just have to find the setup that is going to work for me. bad news though, i still went through a quart in 150-200 miles....
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Re: where is my oil going?
[Re: RodStRace]
#558006
12/31/09 11:23 PM
12/31/09 11:23 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
how with drawings
http://www.envalve.com/how.html
If you notice while the engine running it never closes,
as vac decreases it opens wider... idle still maintains
some flow
As to the OP ... if it blew the valve out of the
grommet, you have a blow by problem... have you put
a gauge on the dip stick tube yet
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Re: where is my oil going?
[Re: MR_P_BODY]
#558007
01/01/10 03:18 AM
01/01/10 03:18 AM
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Joined: Jul 2006
Posts: 4,179
California
mickm
OP
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OP
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Joined: Jul 2006
Posts: 4,179
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Quote:
As to the OP ... if it blew the valve out of the
grommet, you have a blow by problem... have you put
a gauge on the dip stick tube yet
didn't blow it out of the grommet, this was a breather stuck down over the filler pipe coming up out of the valve cover. the other breather is tighter, and has never been an issue. this one was looser, and i wondered about it when i put it on, but figured it would be ok. apparently not.
as far as the gauge, i have a pressure/vacuum gauge, but i'll have to rig it up with the right fittings to go over the dipstick, i haven't done that yet. will see if i can get to that this weekend.
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