Peterson Dry Sump for BBC

Discussion in 'PSI Superchargers Tech Questions' started by Critical Mass, Dec 11, 2010.

  1. Critical Mass

    Critical Mass Member

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    I'm changing from a wet sump to a Peterson dry sump system on my Blown Alky BBC drag boat motor. My questions are what pressure should I strive for and what weight oil should I use? I have always used the old rule thumb of 10 psi for every 1000 rpm. Since I'm turning around 8000 rpm, that would give me an 80 psi oil pressure. My bearing clearances are set at 0.0025 - 0.0028.

    I typically have to change the oil after about 6 or 7 rounds due to the alky contamination. I have used Valvoline 20-50 racing. Some people say that is too thick for a dry sump system? Your suggestions are greatly appreciated.

    Joe
     
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  2. jay70cuda

    jay70cuda Well-Known Member

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    I run a 5.0 in bore center blown chevy with an Autoverdi dry sump with air oil separator . Idling at 2300 I see about 95-100 psi. At the top of the gear change 9500 it's usually about 140 psi. I only run brad penn 50 wt. It's the best oil out there. Never seen an ounce of bearing problems. I made about 20-25 passes on the oil before I change it. Yes I drain it and boil the alcohol out of it. Great oil. Many racers agree. Jay
     
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  3. Critical Mass

    Critical Mass Member

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    Jay,
    Thanks for the tips. I have heard that Brad Penn oil is the best. I have used my pan heaters to try to remove the alky but its not like draining it and heating it. My new system will make it a lot easier and faster to drain it and remove the alky. I plan on driving the 5-stage pump at 54%; I believe that is the typical ratio?

    Thanks again, Joe
     
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  4. Creech

    Creech Member

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    Peteson recommends redlining the oil pump at 5000 so 54% would be good for a motor redline of about 9200. With oil clearance of .03 or less I wouldn't use any thicker than 50 wieght. Alot of blown pro mods use 5 stage dry sump and I think most of them use 60 or 70 wieght but most all out drag race blower motors have .005 or .006 bearing clearance.

    Marty
     
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  5. overkill69

    overkill69 Member

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    oil

    80 psi should work with those clearances. 8000 rpm in a boat sounds easy. Unless you have engine height or bearing issues I'd put a big wet sump on it and a titan pump.
    We turn 9000 with a well engineered BBC wetsump and redline oil.Around 2500 hp. It's on the edge,as Brad Penn made some bearing issues on the dyno that redline seemed to cure.
    We've run over 40 passes on the oil and just set it in the sun between races. Might even try another season on last years batch.
    Or new chassis needed a lower engine positon that mandated a drysump but after looking into the complexity and weight we opted to raise the engine.
    Do a search, there's a lot of chatter on oil.
     
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