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Thread: A/F ratios

  1. #1
    Senior Member RACING JUNKIE
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    A/F ratios

    How lean can one go and still not get into detanation in a N/A engine on methanol? For instance in my sbc 406 about 4.75/1 is as lean as i have tried. I still get quite a bit of oil dilution, so i assume I am still pretty rich, but I am afraid to go much leaner for fear of burning a hole in a piston. does anyone know if I can go, say 5/1 or maybe a little more 5.25/1 and still be safe, and maybe solve some of the dilution or at least cut back on it some.

  2. #2
    Senior Member DYNO OPERATOR
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    I don't really know about a/f ratios, but, if it were mine. I'd tune it to run the best and quit worrying about it...

  3. #3
    Senior Member RACING JUNKIE
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    4.75/1 was its best E.T. and speed to date, and I would like to try it leaner, but I am worried about burning my engine down. However, I still appreciate your input, thanks.

  4. #4
    Senior Member RACING JUNKIE
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    Quote Originally Posted by suicidebomb
    4.75/1 was its best E.T. and speed to date, and I would like to try it leaner, but I am worried about burning my engine down. However, I still appreciate your input, thanks.
    Where did you get these #'s from?, you need to run an EGT and keep the #'s around 1100 degrees on topend. if you go leaner than that you will burn something down.

    JMO

    Zip.

  5. #5
    Senior Member DYNO OPERATOR
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    Don't be afraid to lean it out. You'd have to go really, REALLY lean to hurt it unless you're running nitrous or some sort of forced induction with a lot of boost....

  6. #6
    Senior Member DYNO OPERATOR
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    Another thought, if you're injected, the oil delution could be the barrel valve adjustment, or running the engine too cold w/carb or injection...

  7. #7
    Senior Member RACING JUNKIE
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    Like ZIP said you need an EGT.

  8. #8
    Senior Member RACING JUNKIE
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    Where can I get an EGT?

  9. #9

  10. #10
    Senior Member RACING JUNKIE
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    Also here for duel setup $300.00

    Zip.

    http://www.exhaustgas.com/ProductDet...ID=sub2&RepID=


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