Washing down cylinder walls, MFI and methanol?

Discussion in 'PSI Superchargers Tech Questions' started by Wheelsup69, Oct 19, 2018.

  1. Mike Canter

    Mike Canter Top Dragster
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    You should call Total Seal because they had problems with some rings losing tension and pumping oil. If these are the problem rings they will replace them free.
     
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  2. Wheelsup69

    Wheelsup69 New Member

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    We suspected that at first also. Tried different intake gaskets and ultimately just glued them in place to make sure it wasn't leaking there. As I mentioned I ran a bead of Right Stuff around each intake runner on both sides of the gasket and let it seal. After taking apart there was no sign of leaking at the gasket.... I wish it was that simple. Prior to my last race we tore down the motor, installed new rings and honed it. When we fired it up initially, it was clean and there was no oil. It wasn't until I made an attempted pass and didn't realize I had no boost and we were dumping enough fuel in for 2,500 hp and was only making 700, that it wiped out the cylinder walls and the problem was back.

    After talking with several knowledgeable people the only thing we could come up with was that while under boost and with poor seal between the rings and the cylinder walls, it is pressurizing the crankcase and somehow pushing oil back up into the combustion chambers of the cylinders that aren't firing and when the valves open on those cylinders, it's pushing the oil back up into the intake runners..... We do run 11 quarts of oil in this motor based on New Century's recommendation. Maybe it's just too much oil in the motor....
     
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  3. Wheelsup69

    Wheelsup69 New Member

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    These rings were just bought from them two months ago. Are they having issues with rings that recently bought?
     
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  4. Wheelsup69

    Wheelsup69 New Member

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    I appreciate all the comments and thoughts. This has been a very frustrating problem this year.
     
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  5. sammy christian

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    I think this is a case of imagining a problem that isn't logical.
    There is no way oil is passing the rings under boost and ending up in the intake ports behind the valve.
    Has to be an intake leak. Or valve guides that are wasted.
    Adding sealer to something that's machined wrong isn't going to fix the problem.
    If it was passing the rings, your puke tank would be full every pass.
     
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  6. Wheelsup69

    Wheelsup69 New Member

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    You are probably right. I'm reaching for answers. That is what we suspected for most of the season. Maybe I need to go back to it. I've checked the angles between the intake and the heads very carefully and they were good. I don't run valve seals but the amount of oil seems to be too much to go past a valve, and we've checked them for wear. Puke tank is not taking on much oil at all.
     
    #26
  7. TOL

    TOL Active Member

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    Maybe follow the oil path backwards? Are runners and manifold wet? Throttle body? Could you be losing ProCharger oil? If you had a lot of oil in the cylinders, you should be experiencing some detonation I would think?
     
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  8. Mike Canter

    Mike Canter Top Dragster
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    Don’t know the time frame of the defective rings. No telling how long some sit on a shelf. If i remember correctly it is the oil rings that were bad. I wouldnt do anything to the engine until you talk to Total Seal.
     
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  9. Bjs344

    Bjs344 Member

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    If you're not filling your puke tank then you're missing something. You're moving oil from a volume that should be at atmospheric pressure into another volume that's at 3+ atmospheres yet the canister attached to the first volume remains empty? An inadequate puke system will cause you lots of problems.
     
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  10. buzillamini

    buzillamini Member

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    Are you sure the rings are being put on the pistons correctly? I hate to admit it but we chased a similar situation a few years back only to eventually find a ring installed upside down. We run a mfi twin turbo deal that we keep plenty rich and never have had a washdown issue.
     
    #30
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  11. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    I would think if the ports were getting enough oil to do as described, it would be no doubt as to that being the problem - the ports would still have oil in them after a run. I have heard of BBC's doing this in the shutdown when there is no boost, but I don't think there's any way crank case pressure is exceeding the boost pressure in the port.

    Did you by chance have the check valves off of it and maybe got the idle check installed backwards? Make sure you don't have multiple jets stacked in the BV so that it has the bypass passage blocked off?

    I'm not saying your theory can't be right, but rarely when we have to dream up something like that is it right. Occam's razor is a great principle to live by in racing - the simplest explanation is usually the correct one.

    Even with collectors, I would think it would have to be so rich at idle it would be huffing raw fuel out of the collectors like an irrigation system. Also if it ran fine before, the same tune up is not going to go that rich without you making a major change.
     
    #31
  12. Wheelsup69

    Wheelsup69 New Member

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    I will go through my set up with a fine toothed comb. There could be something backwards. Thanks for everyone's input on this.
     
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