Blow By on a fresh rebuild. Possible ?? PLEASE HELP. Pics inside

i've not read every post, but from the ones i have there has been a lot of good info posted on his smoking problem.

with liquid oil dripping out the tail pipe, once the problem is repaired with a good stock motor doing only short trips it can take a few hundred miles for the smoke to clear up. if the exhaust has been behind bad smoker for a long time & the oil in the exhaust is caked up, it can take a couple of thousand miles for it to clear out.
it takes heat to burn the oil out of the exhaust & you can't really make enough with short trips. take it out & drive for at least 50 miles non-stop & see what it looks like.
keep a close eye on the oil pressure & check the oil both before you start & at the end of the 50 miles.


for future reference i'll add that you can do a quick check for the intake gaskets leaking by pulling both the breather & PCV valve from the valve covers & then plugging the holes. start it up, you don't want to rev it, just let it idle, pull the dip stick and cover the dip stick hole with your finger & check for vacuum.
being inexperienced, you can use a vacuum gage hooked to the dip stick tube to check it.
i've seen some motors with no problems pull a little vacuum, IIRC the highest i remember seeing was around 2~3 inches or so. the main thing is if it continues to climb. with one intake port leaking on a motor with all the other seals & gaskets good, you can see the same amount of vacuum in the crankcase that you see from the intake, usually in less than a minute.


Register now (free) or login to remove ads

Hello Again.

How about stopping by the old guy's shop that built it ? You'll spend your 401k on re-gasketing everything at this rate.


Enjoy

you're right Ed, i should have ruled out the PCV valve before running it. I got too anxious and didn't pay attention...So I took your advice with a little twist. I rigged up a $20 DIY oil catch can using home depot items...




I would have just plugged the PCV and ran it like that but then I would have never know exactly how much oil is being sucked in, if indeed the PCV is the culprit.

However, I also disconnected the tranny modulator valve from the intake port. You brought up a good point in saying that we dont know what oil is being burned. I have noticed a decrease in tranny fluid but I had thought it was something else. As you guys may or may not know, I am running a hydraulic suspension but haven't upgraded to a telescopic drive shaft. Therefore when I raise or lower the car, the stock shaft tends to push on the rear tranny seal causing a leak. That's why i thought my tranny fluid was low. BUT when you brought up the modulator valve it hit me that that too is vacuumed to the intake manifold. Anyhow, I unplugged it to rule that out as well.

Here are my observations...

Total run time: 1 hr. broken down as follows:

30 min at idle followed by a 30 minute drive.

It made it a little difficult to bring the driving speed up because the tranny would not shift out of 1st gear. I'm assuming that has to do with the vacuum line being disconnected from the modulator.

After the hour past, this is how much oil had accumulated in the catch can...



NOTE: The car smoked during this time. I'm guessing all the gunk has not burned off yet.

Would this be a good time to pull the header off and check to see how the exhaust valve is doing? or should I do the same 1 hour run time process for a few more days ?

That is a LOT of oil for such a short run time and not even a high RPM run.

Since you have added the baffle plate that Edelbrock sent you there should not be that much oil getting to the PCV valve.

Is the oil draining back down from the heads? Are the drain holes in the head restricted? How much oil pressure do you have at cruise RPM? Are you running a high volume/high pressure oil pump?

I agree that is a lot of oil for such a short run. It is also hard to tell, from your pictures, if the valve covers are short, or tall. By installing a set of tall valve covers, you move the PCV valve up, and farther away, from the oil splash coming off of the rockers.

My oil pressure stays at 50 psi during idle. And bounces from 40-60 depending on throttle at cruising speeds.

Oil pump is stock if i'm not mistaken. Only thing on the bottom end that I did was notch a small section of the windage tray in the oil pan to clear the oil pump pick up... Could this be causing the excessive oil to the heads?

valve covers are short I suppose. Close to what the stock covers are...

Could I add some material in the baffle to block some of the oil?

Luis,

As I suggested, buy a permanent type furnace filter at Home Depot it is the type that has the synthetic weave (blue or brown, whichever) , cut out a small rectangle of it and remove the baffle, put it inside the baffle and put the screws back in. This will allow vapor to pass but limit liquid and reduce some vacuum.

The filter will cut with a good set of shears and is about one inch thick, this was good for my use.

To shift the transmission, start in low and run it up and change gears manually.

Luis,

What's happening with your Impala?

Luis,

Were you able to come up with a solution to your problem. Can you bring us up to speed?

Luis, I have followed this entire post as well and just read through the 13 pages of it in 3 HOURS!! I am having the EXACT same problem on my build and have made a few posts of my own recently. I know you haven't replied for a while now but I would love for you to fill us all in on the status of your engine and if you found the culprit for the burning oil. I am in the exact same situation you were with my build and I would really appreciate hearing from you to find out what the reason was in your case.

Hope you still visit this site and see this!!

Keith

Pizza dude. By any chance, did you use standard fel pro intake gaskets?
The standard fel pro`s on a aluminum intake don`t work real well as they won`t crush and seal due to the lack of the intakes weight.
The standard gaskets are for cast iron intakes as there weight and bolt tightness will "crush" the gasket and create the seal. So, remove the carb and look into the intake plenum. If you see oil everywhere you have a intake gasket leak. If not then the problem is elsewhere. Give us more detail on how your engine uses oil and if you see any clouds of smoke and the color of it coming from the exhaust as well as the type of oil you used. Unless the PCV system is set up uncorrectly you can`t point the finger at it and blame it for excessive oil use. Give us the answers I`ve asked and I`ll tell you in total how the PCV system works and how it has to be restricted to work correctly.

Was the issue with the Impala ever resolved? I just read this book of a thread and was left hanging at the end

Why don't you PM the OP?

__________________
''Life's tough, Pilgrim, and it's even tougher if you're stupid.''---John Wayne

Midnight Sun Street Rod Association