Chamber Destruction

Discussion in 'PSI Superchargers Tech Questions' started by Bjs344, Oct 30, 2019.

  1. Bjs344

    Bjs344 Member

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    Whole right bank. Left bank still runs, lol. If the left bank is unhurt when I pull that head I will be really lost.

    The chambers are surprisingly thin in the quench pad.

    I did not zoom in on Grid ignition in/out trace. I’ll do that this weekend after I get it disassembled the rest of the way.

    Just a thought. There’s no way it did this on startup right??
    The squirt bottle was probably half pump gas half alcohol or maybe all pump gas. We’ve started it hundreds of times the same way, although I did think the initial squirt was a little light

    Surely it took a bunch of heat that couldn’t be generated during cranking?
     
    #21
  2. Mike Canter

    Mike Canter Top Dragster
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    You are correct in that you can’t do it with the squirt bottle start
     
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  3. Bjs344

    Bjs344 Member

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    Left side looks similar, probably 1/4 second behind in going nuclear.

    3 of 4 chambers caved in about to give out. Orings pushed out. #5 was always a 1/2 thread colder and never did anything about it. It is the only undamaged chamber. Oring still in the groove.

    Looked at the plugs again. Multi run plugs with color down to the 3rd thread but not really burning/chalking much. Nothing i haven’t seen before even though some would be scared of them. Definetely no eroding of the electrode which is what made me back off in the past.

    I still need to check the grid in/out

    Going to take the pump to alky digger to get it flowed and make something more robust to hold the fuel valve open. I don’t like the tape because I work the leanout a little before the burnout and we can’t get to it with the hood on.
     
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  4. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    If you have a lever in the car, you can tighten the bolt on it to make it more difficult to move.
     
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  5. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    If the pump is cavitating at higher rpms, it's possible that it may cause detonation all of a sudden once it starts cavitating.
     
    #25
  6. SoDak

    SoDak Active Member

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    Sounds like what we had some years ago, it ended up being a oring on the inlet of the pump that was torn. How it got torn or why it didn’t show up until many runs after it was assembled, I have no idea?
    It too would not show on the plugs but melt aluminum out of the chamber, how that’s possible is beyond me.
    It would only do it to the right bank and putting in a smaller main pill would not richen it.
    It’s easy to check
     
    #26
  7. Bjs344

    Bjs344 Member

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    I had the pump flowed at alky digger. Original tag when I got it used was 15.1

    Flowed 13.8

    I think their bench is a little on the low side.

    The blower hadn’t been stripped in awhile so I think the pump and the blower were going away just a little at the same time, keeping the tuneup happy, but running a little slower.

    I’m leaning towards I actually started to hurt them a few passes earlier when I know for a fact I missed the tuneup (air came in 1000’ while in the lanes) and they just finally caved on this run.

    Two different people looking at the heads up close said the deck was too thin for what I was doing and I was probably lucky they held up as long as they did.

    Still debating whether to replace the pump. New combo won’t need as much fuel so 13.8 would be fine if it’s consistent.
     
    #27
  8. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    You are correct, every flow bench is different. Obviously the temp of the solvent they are using to flow with is critical as well.

    Did Mike inspect and service the pump and give it a clean bill of health?

    That's the thing about vane pumps is they go away. If it's going away because of internal leakage, then it will cavitate with rpm. The more leakage, the lower that rpm may be.

    The more "good enough's" we eliminate from our racing program, the better we are. I'm not saying that to be condescending, I remind myself that all the time. One engine builder told me "perfect is barely acceptable."

    The Enderle gear pumps are priced right and are a nice piece. That is the direction I would go.
     
    #28
  9. Bjs344

    Bjs344 Member

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    Will, I was in a hurry when I stopped by with the pump. Mike said based on it being very old and the flow numbers, toss it.

    Actually, if you replace the Texas twang with a southern drawl, you and him said the exact same thing.

    I guess sometimes a guy just needs to hear it twice to do the right thing.
     
    #29
    Will Hanna likes this.

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