oil pressure BBC

Discussion in 'PSI Superchargers Tech Questions' started by Wild Bill, Oct 9, 2011.

  1. SoDak

    SoDak Active Member

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    Do you have a typo here? Is it 1/2" or .050"? Either way I'd change it to about 1/4".

    You're bearing clearances around .004" sounds good.

    You should have more than 60 psi. I had a sump pickup once that got covered too much over the inlet and it had NO psi at idle.
     
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  2. Animal1

    Animal1 Member

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    Have you check how the distributor lines up in the block, we had that problem once. The oil leaked by, also you should have at least 100 psi going down the track. We ran 509 BBC with 34 timing, 44 over on HH littlefield and ran 6.20's in an altered motor was rich and it liked the timing.
     
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  3. alcohol altered

    alcohol altered New Member

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    If I put 34 degrees of timing on my 498 BBC it is a lazy dog. The party wont even get started in my engine until at least 38 degrees. Been as high as 43 and plan to keep going until bearings start to smash. 40 degrees is when It makes a HUGE difference in my engine. Running conventional heads with Super Mag IV
     
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  4. craig moss

    craig moss Member

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    R u buzzin it or using a timing light ??
     
    #24
  5. alcohol altered

    alcohol altered New Member

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    I buzz it then use the timing light. The guy that flowed my fuel system said he regularly ran 44 degrees in his blown BBC. I kept creeping up on the timing and measuring rod bearings every 2 runs. So far no crush and no signs of detonation.
     
    #25
  6. SoDak

    SoDak Active Member

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    I'm very surprised.
    Have you tried this on the dyno?
    I wonder if your timing marks are off.
    One day on the dyno for us we took timing out and the plugs went cold so we leaned it and we made more power with less fuel and less ignition lead than when we started. We have BBC conventional heads, SM IV and high 20's for boost.
     
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  7. alcohol altered

    alcohol altered New Member

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    Never been on dyno. Have had motor apart couple different times and always double checked the timing marks when going back together. At 34-38 degrees didn't really notice much difference. When I put it up to around 40-41 it made a big difference. Lonnie Houde is the one who turned me onto this. He really seems to know his stuff and he did my fuel system. I run conventional style BBC heads (Pro topline 360 X heads built by Jim oddy) Merlin pro race block 4.50 bore 3.90 stroke. Crower rods and crank.
     
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  8. Blownalky

    Blownalky Top Sportsman

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    When you read your plugs, how do the ground straps look at say 34 degrees and then at 41? Where is the "blue line" and does it move when you make the timing changes?
     
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  9. alcohol altered

    alcohol altered New Member

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    At 34 degrees without changing the fuel setup there is no noticable line on the plug (they look new) But I dont compensate my fuel for that low of timing. Im sure I could get some heat in the plugs at 34 but I really have no reason to run that low. At 41 its frosty about 3/4 of the way around the base circle of the plug, at 43 pretty much the whole plug is frosty and if one cyl is a little leaner than the others it will start burning the ground strap. I havent ran less than 38 degrees in at least 3 years.

    I have melted pistons out twice by getting greedy with the fuel. There isn't that much room for error in my opinion at 41 degrees plus. I run a Rage fuel pump with 22 injectors 10 in the hat and 12 in the ports. Maybe I run alot more fuel into the engine than most Im not sure, but I do know that this much timing works in my application for me. I'm not trying to get guys to go out and put 43 degrees of timing in their BBC and blow up their motor. I spent a couple months testing before I got my combo figured out. I just bumped up the boost so I am starting over again at 38 degrees checking bearings every 2 passes or so. I want this thing to run in the 3.90's
     
    #29
  10. craig moss

    craig moss Member

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    Well I would say u keep good company. Them boyz ain't don't fool around
     
    #30
  11. 32 bantam

    32 bantam Member

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    How many GPM going into the engine?
     
    #31
  12. 32 bantam

    32 bantam Member

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    22 nozzles? 10 in the hat OK.....12 in the ports??? 8 cyl.engine...how do you have them placed?
     
    #32
  13. 32 bantam

    32 bantam Member

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    another question... compression ratio?
    your post has me thinking !!!!!!!!!!!!
     
    #33
  14. alcohol altered

    alcohol altered New Member

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    According to the jet size program, that I think I have figured out, it is putting in 7.51 gpm.

    I run 11.5:1 compression.

    That is correct, I have 12 nozzles in the ports. Each of the front 4 cylinders run 2 nozzles per cylinder. I have the nozzle sizes divided up so that when I stage it runs off of the normal nozzles like the rest of the engine, but the other 4 extra nozzles in cylinder 1-4 are spring loaded poppet nozzles (25psi if I remember correctly) that don't come in till I put the hammer down, that way It will not flood out the front holes early on. Even though I have the blower set back I still have to run a ton of fuel into the front 4 holes to keep the temps down. If I just ran normal nozzles up front I'm pretty sure it would put a couple holes out.

    I didn't dream this stuff up by myself like I said (b/c I probably couldn't have). Lonnie Houde helped me alot in getting the fuel system done right. I really haven't been able to run my car this year due to some other projects that needed to get done. Next year I really hope to focus on getting this thing in the 3's.
     
    #34

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