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Blue smoke-Help!

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  • Blue smoke-Help!

    Saturday, I attended an autocross on a fast, clockwise course. The last sweeper was fairly fast, with a full throttle exit from a late apex. On this section, the car started emmitting blue smoke and exhibited a crackling misfire. As far as I can tell, this didn't occur anywhere else on the course, and I saw no smoke on the 90 mile drive home from the event. When I got home, I found the car had used almost 1/2 quart of oil. In the 1800 miles since my last oil change, the car has used less than 1/3 quart, and it was full when I checked it Saturday morning before the event. The car is equipped with an SVT Zetec with a Raceline wet sump, and the block and heads are stock, save a camshaft upgrade and some tuning changes (no porting, polishing, or other modifications). The motor was new when I acquired the car, and now has 3700 miles on it. I have been to several autocrosses with the car, and not had this problem, but I have also never run on a course with this particular direction/speed/g force of curve. What causes should I be looking for, and what are the possible cures?
    Brad
    2013 Boss 302 Mustang
    2005 SV Roadsport (gone but not forgotten)

  • #2
    Am I correct that this sweeper was a turn to the right?

    My Zetec engined Seven has produced clouds of smoke after hard right hand turns.

    On the left side of the block is the crankcase breather (black irregular shaped can) and polution control valve (PCV). The tube from the PCV on a stock engine goes to the intake manifold.

    Best guess is that oil is being thrown into the breather, gets past the PCV and is drawn into the intake.

    It only takes a small amount of oil to make lots of smoke.

    I plugged the tube leading to the intake and routed the tube from the PCV to a catch tank. This solved the smoke problem but now the catch tank would fill with oil during track days.

    I removed the PCV at the suggestion of Woody at MSI. This greatly reduced the amount of oil going to the catch tank. I believe the PCV was acting as a one way valve, any oil that gets past it is trapped in the line to the intake, as the valve opens and closes it pumps more oil into the intake or catch tank. Without the valve the oil can drain back into the block. I actually just cut the large end off the PCV and removed the spring and ball, you can buy a fitting to replace it but this was simple and it worked. If you do it this way cut right at the large as it's just a slip fit into a rubber grommet.

    Smoke problem solved and less oil usage. If I put 5 liters into the sump I'll still get a small amount into the catch tank but this stops after the oil level drops just a bit.

    I believe Gert aka Slomove just sealed up the PCV outlet and has the top valve cover outlet going to the catch tank with similar results.

    Doug
    Last edited by Doug Liedblad; July 14, 2008, 01:39 PM.

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    • #3
      Sure sounds like the same problem. Thanks for the ideas; I've got until August 8th to fix it. Btw, what did you use for the catch tank?
      Brad
      2013 Boss 302 Mustang
      2005 SV Roadsport (gone but not forgotten)

      Comment


      • #4
        I used a Jaz catch tank with breather. One quart. One pint is too small. I mounted it in front of the pedal box with some insulating material around it due to close proximity to headers.

        On the track both oil breather and radiator overflow must go to a catch tank.

        I route both into this. The radiator already has an expansion tank so the catch tank is a backup in case it overflows. It has done this once when the serpentine belt came off.

        http://www.jazproducts.com/breather_tanks.html

        Except mine has two AN6 inlets, I no longer remember where I got it. Jaz will install another for the price of the fitting.

        I use one for oil, one for coolant.


        Caution! Never assume that the catch tank is not full and try to drain it into a container smaller than the catch tank.

        Doug
        Last edited by Doug Liedblad; July 14, 2008, 03:21 PM.

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        • #5
          Originally posted by Doug Liedblad View Post
          ......I believe Gert aka Slomove just sealed up the PCV outlet and has the top valve cover outlet going to the catch tank with similar results.....
          Yes this is what I did but I am going to undo that. It worked well under normal driving conditions but with the accelerated blow-by of my obviously worn engine the smallish valve cover vent could not keep up and the whole engine got pressurized, seeping oil from the valve cover during track conditions.

          I am now going back to a regular double vent (5/8 hose) from the crank case (no PCV) and the valve cover into my new bigger K-Mart catch can (0.75 liters) , see picture.

          Gert

          P.S.: I know Chris will get a kick out of the catch can...
          Attached Files
          Last edited by slomove; July 14, 2008, 09:14 PM.

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          • #6
            Hey Gert, are you related to Pierre? I recall he used a tennis ball container as a catch can at one point. :cool:
            | | Sean

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            • #7
              Originally posted by Sean View Post
              Hey Gert, are you related to Pierre? I recall he used a tennis ball container as a catch can at one point. :cool:
              kind of....European attitude?

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              • #8
                Originally posted by slomove View Post
                kind of....European attitude?
                As an Irish citizen, I shouldn't have any trouble locating an empty Guinness can around here somewhere to use as a catch can on my car... :D
                I wonder if that would be technically illegal, having an open container in the engine bay?
                | | Sean

                Comment


                • #9
                  P.S.: I know Chris will get a kick out of the catch can...
                  Gert! That is totally rad! Aluminum no less! I was figuring you'd post a pic of some plywood, chewing gum...:D
                  Chris
                  ------------
                  A day you don't go a hundred is a day wasted

                  Comment


                  • #10
                    So Brad, did you determine the source of the problem? If so, have you implemented a solution?
                    | | Sean

                    Comment


                    • #11
                      Enough people have pointed to the PCV system as the culprit, and it is located in the right spot to be the villain, so I have ordered an 1840 ml catch can from SPA Turbo and Central Florida Motorsports (www.c-f-m.com). The next issue is whether or not to kill the PCV system and vent the catch can with a filter, like Doug and Gert. Because my car uses a Ford ECU, not an aftermarket, and because I have spent much time and $$$ dialing in the tune, I am going to run the catch can in line and retain the PCV system. I can always replace the line from the catch can to the air intake with a filter (and block off the intake hole) if I want to fiddle with which way is better. I will post pics next week. I welcome debate on PCV or not PCV; some of my questions are:
                      Does Ford's ECU expect a vacuum in the PCV system?
                      Will eliminating the PCV recirculation result in appreciably cooler air in the intake, and what, if any, performance boost could be expected?
                      Will venting the catch can to a filter right in front of the driver create extra heat/smells?
                      The only way I can tell if I've solved the problem is to recreate the circumstances (I think), and I will have to wait for another clockwise autocross, unless I can find a big enough empty parking lot. Any thoughts on alternative testing methods would also be appreciated.

                      Btw, If you have an SVT engine, I highly recommend CFM's billet DSI clip to replace the shite plastic one provided by Ford. $37.50 well spent.
                      Brad
                      2013 Boss 302 Mustang
                      2005 SV Roadsport (gone but not forgotten)

                      Comment


                      • #12
                        If you are using the stock ECU how did you tune it? I believe it can be done with the correct software tools but have never tried.

                        I don't think the ECU will care much if the PCV is hooked up or not. It's either flowing air / vapor from the crankcase or it's not. They do cycle on and off depending on the pressure in the crankcase. If I recall the intake from the PCV into the manifold was downstream of any sensors. Except for the Lambda sensor.

                        I cannot recommed you intentionally try to suck more oil thru the intake. It causes immediate detonation / pinging that might be damaging. A few seconds probably didn't hurt but the oil makes it into a diesel.

                        Removing the PCV and routing to a catch tank will solve your problem. Just dump it. You don't need it - no signficant difference. This is how Swedes debate.

                        As for heat / smells from the catch tank, you won't notice any unless it overflows and then not much.

                        Do you already have the air filter located so that it gets a cold air intake? Some of the stock setups put the intake behind the engine where the intake air temp was 30آ؛ above ambient. Costing you several HP.

                        I don't see the catch tank on the SPA turbo website or the Central Florida site. FOUND IT. It doesn't look to have a breather on the top which can be corrected.

                        Doug
                        Last edited by Doug Liedblad; July 17, 2008, 09:23 PM.

                        Comment


                        • #13
                          Originally posted by athens7 View Post
                          Any thoughts on alternative testing methods would also be appreciated.
                          I'm thinking an out-of-the-way cloverleaf during off-peak traffic hours would be ideal for testing this - four 270آ° right turns connected by short straights! :cool: Of course, the "out-of-the-way" part is where it gets tricky...
                          | | Sean

                          Comment


                          • #14
                            Originally posted by athens7 View Post
                            some of my questions are:
                            Does Ford's ECU expect a vacuum in the PCV system?
                            I'd say no. There is no crank case pressure sensor, and the mass air flow sensor doesn't really care where the air flowing over it comes from. The PCV is a simple feedback loop in place so that any hydrocarbons exiting the crank case gets combusted.

                            Will eliminating the PCV recirculation result in appreciably cooler air in the intake, and what, if any, performance boost could be expected?
                            I'd say no again. I believe the air that the PCV vents from the crank case originates from ring leakage during the compression stroke. This volume is so small that its temperature when it re-enters the intake system does not affect the performance.


                            Will venting the catch can to a filter right in front of the driver create extra heat/smells?
                            Maybe, but I don't think you will notice it, unless you have some serious ring issues. Looking at the hose going from the crank case to the intake system, it is neither of a large diameter or very much pressurized (if at all).

                            The only way I can tell if I've solved the problem is to recreate the circumstances (I think), and I will have to wait for another clockwise autocross, unless I can find a big enough empty parking lot. Any thoughts on alternative testing methods would also be appreciated.
                            You could probably jack up the right side of your car while it is idling to simulate centrifugal forces. At some point the PCV valve should start to suck yummy oil and give you a smoke show.

                            /Magnus F.

                            Comment


                            • #15
                              The ECU has been reprogrammed with a Diablosport Predator handheld programmer, and several hours of tune time with a Diablosport dealer who has the software.

                              The cloverleaf sounds like a good (and fun) idea, but I live in the country and I can't think of one within 30 miles. Guess I'll try the jack idea.

                              I'm inclined to leave the PCV system intact for now, adding the catch can in line. The way we intend to route it, it would be almost impossible for oil to make it to the air intake. I have also learned that any time one modifies a machine as complex as a car, the mod will (usually) have the desired effect, as well as one or more undesired ones. I agree that the PCV hose to the intake is downstream of the MAF sensor, so I'm probably worried about nothing.

                              I would love a CAI, but the only good ways I can figure to work it is to either eliminate the heater, which I don't want to do, or cut a hole in the bonnet and attach a scoop, which is an off season project. I would love to see pictures of or hear about any SVT CAIs that are out there!
                              Brad
                              2013 Boss 302 Mustang
                              2005 SV Roadsport (gone but not forgotten)

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