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torqhead · 07-05-2005, 03:47 PM

I've built a new 455 and put it in my 69 GTO. The problem I experience is when I RPM the motor to 6000 in 3rd and shift to 4th and decel the PCV valve sucks oil through it into the manifold therefore
causing an enormous amount of smoke out the exhaust. I have validated this is what is occurring by disconnecting the PCV valve and running the test multiple times, the problem does not occur again.
I'm currently running one large open element breather cap on each valve cover.

Anyone else experience this problem or have any ideas what may be going on?

Lloyd-TX · 07-05-2005, 03:57 PM

Either your OEM pushrod cover has been "modified" by removing the inner baffling, or you are running an unbaffled aftermarket pushrod cover - either of which allows oil splash to enter the valve, or your engine is seriously overfilled with oil, or ???

LouisianaGuy · 07-05-2005, 04:15 PM

Torq, My fresh 455 did the same thing at WOT in 3rd it would make a james bond smoke screen....Change the oil nad put 5 quarts instead of 6 and see what happens. It will likley stop.
I forgot about it once and put 6 qts in my car took it to the track and made smoke...Drained one quart at the track and voila no more smoke...My valley pan is unmodified so I dont think that is the problem...althoe I do have another pan im going to try out later to be sure that isnt what it was..but till then i run 5 qts of oil and everything is good.
Mike

torqhead · 07-05-2005, 07:49 PM

Another piece of info is I have installed Edelbrock valve covers with the baffle/plate installed. The PCV is in the valley pan between 2 and 4 intake runner.

torqhead · 07-05-2005, 07:53 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by LouisianaGuy:
Torq, My fresh 455 did the same thing at WOT in 3rd it would make a james bond smoke screen....Change the oil nad put 5 quarts instead of 6 and see what happens. It will likley stop.
I forgot about it once and put 6 qts in my car took it to the track and made smoke...Drained one quart at the track and voila no more smoke...My valley pan is unmodified so I dont think that is the problem...althoe I do have another pan im going to try out later to be sure that isnt what it was..but till then i run 5 qts of oil and everything is good.
Mike </div></BLOCKQUOTE>My experience exactly as you described, Bond smoke screen. I'm running a 7 quart oil pan, are you saying when you dropped it a quart that it would no longer pull oil through the PCV? It seems strange to me that this is occurring since I thought the purpose in a PCV was on high vacuum that it would pulled the ball or whatever is inside the PCV up and close off the line. I have replace the PCV with a new one as well.

LouisianaGuy · 07-06-2005, 07:18 AM

Torq, Yeah I just added one less quart of oil and it wont smoke, I have done this a few times to be sure that is the problem and every time if stops smoking after I drain a quart out....Its pretty funny at the track...I run to the end and she starts smoking about the 1/8 mile when I get to the end the little clean up truck is coming behind me looking for the "Blown up pontiac parts" LOL I then tell em I have too much oil adn they dont chase me down the track anymore LOL. Try running only 5 Quarts of oil and see what happens....I just try to avoid really hard cornering....not that it would hurt any thing, I just like to be over cautious.
I always assumed the same thing about the pcv valve, so I started trying a few different valves out to see if maby the spring was too heavy or too light....They made no difference...I am going to put my other valley pan on and then run 6 qts of oil to see if it changes anything, but I dont imagine its going to....Another funny thing I knoticed...I just put a motor in a friends Mach 1 for him and the little ford produces enough vac, that you can put your hand over the oil fill hole in the valve cover and it will literally start sucking a hickey on your hand and the engine will actually begin to run rough after a time...I cant ever remember my poncho being like that...we had to put vented breathers in his valve covers.
Mike

rexus31 · 07-06-2005, 07:58 AM

Just a stupid question: If the factory calls for 6 quarts, will running 5 quarts damage the engine in anyway?

David Jones · 07-06-2005, 08:10 AM

If you are running the PCV in the valley pan, put it in one of the valve covers.

Junkyard Dog · 07-06-2005, 08:10 AM

(1) So, you guys are having the PCV open during low vacuum conditions?

(2) What is your vacuum at the top of third gear?

(3) Is blow-by perhaps causing pressure in the crankcase that opens the valve?

(4) Wouldn't this affect your mixture and thus your horsepower?

torqhead · 07-06-2005, 08:16 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by rexus31:
Just a stupid question: If the factory calls for 6 quarts, will running 5 quarts damage the engine in anyway? </div></BLOCKQUOTE>

No question is stupid... Running a quart low is ok as long as the engine doesn't get starved for oil. In my case I have installed a 7 quart oil pan and run a high volume pump. Running a quart low shouldn't be a problem for me. If you're running a standard oil pump with the stock oil pan, this shouldn't be a problem either. Key is to avoid running out of oil in the pan... :-)

torqhead · 07-06-2005, 08:21 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JunkYard Dog:
(1) So, you guys are having the PCV open during low vacuum conditions?

(2) What is your vacuum at the top of third gear?

(3) Is blow-by perhaps causing pressure in the crankcase that opens the valve?

(4) Wouldn't this affect your mixture and thus your horsepower? </div></BLOCKQUOTE>

(1) actually I think the PCV is staying open in both cases, meaning during decel which is producing the most vacuum since it's connected to the base of the carb is what is causing it to suck oil into the motor without pulling the ball in the PCV to close it. (At least that what I suspect is going on.)
(2)I don't have a remote vacuum gauge on, but at the top end of 3rd, WOT and 6500 RPM I would suspect basically little to no vacuum.
(3) Wouldn't massive blow by push the valve closed? I also run two large filtered breathers on the valve covers, one on each.
(4) Shouldn't affect mixture unless there is a vacuum leak. Connected or disconnected the car runs the same except for the James Bond smoke out.

torqhead · 07-06-2005, 08:25 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by LouisianaGuy:
Torq, Yeah I just added one less quart of oil and it wont smoke, I have done this a few times to be sure that is the problem and every time if stops smoking after I drain a quart out....Its pretty funny at the track...I run to the end and she starts smoking about the 1/8 mile when I get to the end the little clean up truck is coming behind me looking for the "Blown up pontiac parts" LOL I then tell em I have too much oil adn they dont chase me down the track anymore LOL. Try running only 5 Quarts of oil and see what happens....I just try to avoid really hard cornering....not that it would hurt any thing, I just like to be over cautious.
I always assumed the same thing about the pcv valve, so I started trying a few different valves out to see if maby the spring was too heavy or too light....They made no difference...I am going to put my other valley pan on and then run 6 qts of oil to see if it changes anything, but I dont imagine its going to....Another funny thing I knoticed...I just put a motor in a friends Mach 1 for him and the little ford produces enough vac, that you can put your hand over the oil fill hole in the valve cover and it will literally start sucking a hickey on your hand and the engine will actually begin to run rough after a time...I cant ever remember my poncho being like that...we had to put vented breathers in his valve covers.
Mike </div></BLOCKQUOTE>Hey Mike, Curious, have you run with the 6 quarts and plugged/disconnected the PCV valve? If you're running breathers on the valve covers you should be able to displace crankcase pressure. Effectively doing this test proves that it is going through the PCV instead of past the rings. If it's going past the rings then you've got much more serious problems, ie: holes too big for the pistons, broken rings, etc.

torqhead · 07-06-2005, 08:27 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by LouisianaGuy:
Torq, Yeah I just added one less quart of oil and it wont smoke, I have done this a few times to be sure that is the problem and every time if stops smoking after I drain a quart out....Its pretty funny at the track...I run to the end and she starts smoking about the 1/8 mile when I get to the end the little clean up truck is coming behind me looking for the "Blown up pontiac parts" LOL I then tell em I have too much oil adn they dont chase me down the track anymore LOL. Try running only 5 Quarts of oil and see what happens....I just try to avoid really hard cornering....not that it would hurt any thing, I just like to be over cautious.
I always assumed the same thing about the pcv valve, so I started trying a few different valves out to see if maby the spring was too heavy or too light....They made no difference...I am going to put my other valley pan on and then run 6 qts of oil to see if it changes anything, but I dont imagine its going to....Another funny thing I knoticed...I just put a motor in a friends Mach 1 for him and the little ford produces enough vac, that you can put your hand over the oil fill hole in the valve cover and it will literally start sucking a hickey on your hand and the engine will actually begin to run rough after a time...I cant ever remember my poncho being like that...we had to put vented breathers in his valve covers.
Mike </div></BLOCKQUOTE> Forgot one thing, let me know what happens when you put the other valley pan on. Thanks Dave

Junkyard Dog · 07-06-2005, 08:28 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by torqhead:
(3) Wouldn't massive blow by push the valve closed?
</div></BLOCKQUOTE>

I shouldn't think so. Isn't that the same thing as vacuum on the other side? That is, there is a pressure differential in the same direction.

I don't know the answer to this, perhaps there is something to keep this from happening.

torqhead · 07-06-2005, 08:55 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JunkYard Dog:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by torqhead:
(3) Wouldn't massive blow by push the valve closed?
</div></BLOCKQUOTE>

I shouldn't think so. Isn't that the same thing as vacuum on the other side? That is, there is a pressure differential in the same direction.

I don't know the answer to this, perhaps there is something to keep this from happening. </div></BLOCKQUOTE> Agree, I would think it's basically the same thing... suck it closed or blow it closed... not sure but thanks, now you know why I'm confused... :-)

LouisianaGuy · 07-06-2005, 03:23 PM

I honestly dont remember if I have tried running with out the pcv valve...I think I did once and that is how I figured it was going into the pcv valve, so I reconnected it and then drained the oil for a change and for some reason only put 5 qts in it and it didnt smoke any more. Not to mention I had a lil bit of oil in my pcv fitting on the carb....Only one of my valve covers has a provision for a breather, so that is why I still run the pcv
Mike

69lm69gp · 07-07-2005, 06:54 AM

I have to agree with Lloyd. In order for your PCV to be causing your problem it has to be either sitting in a puddle of oil or getting a lot of oil splashing on it. "Chrysler" had a similar problem with the Mitsubishi 3.0L. The problem was that the baffles on the valve cover that the PCV was installed in where not draining properly causing the PCV to suck up oil like a straw. The fix was to drill drain holes in the baffle to help drain the oil. I am not saying that you should drill holes in your lifter valley cover. But that either your cover isn't draining properly (the Mitsubishi valve cover had drain holes, they just weren't sufficient) or something is letting an excessive amount of oil get into the cover such a modification as Lloyd mentioned.

Junkyard Dog · 07-07-2005, 12:16 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by torqhead:
Agree, I would think it's basically the same thing... suck it closed or blow it closed... not sure but thanks, now you know why I'm confused... :-) </div></BLOCKQUOTE>

Well, actually, I think it sucks open, not closed, and drops closed when vacuum decreases, like when you drop the hammer. If there is a lot of pressure in the crankcase, though, that might push it open. I have never cut open a PCV to look at its interior design, though, so my understanding may be overly simplistic (as usual).

Lloyd-TX · 07-07-2005, 03:06 PM

The PCV valve is a precisely calibrated orifice (i.e. a vacuum leak) with a spring-loaded check valve. Manifold vacuum opens the valve. The check valve is there to avoid the possibility of an intake backfire igniting crankcase vapors - BOOM!

Interestingly, many Japanese cars have no such check valve in the crankcase ventilation system, simply a calibrated orifice.

If indeed it is oil from the PCV system causing you excessive smoke upon decel, the problem MUST be liquid engine oil getting to the bottom of the PCV valve.

The real question is: HOW IS THE LIQUID ENGINE OIL FINDING ITS WAY TO THE PCV VALVE?

One more thought - if an engine has sufficient crankcase pressure to open the PCV valve at full throttle - that engine has MUCH more serious issues than oil getting into the PCV system!!!

JEFF KING · 07-07-2005, 04:22 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by David Jones:
If you are running the PCV in the valley pan, put it in one of the valve covers. </div></BLOCKQUOTE>

I have to go with David Jones on this gentlemen. The Factory had the same problem on the SD-455 engines...
There for they put the PCV in the valve cover.
I myself would not run a quart low at the track or even hard use on the street. Just to solve a simple Fix that will let you run your big buck motor with the right amount of oil in her.

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