Definite max ECR for E-85?

Discussion in 'High Tech for Old Iron' started by 65skylark300, Sep 23, 2014.

  1. slimfromnz

    slimfromnz Kiwi Abroad

    I dont have a very good video of the noise from the tail pipes, but this may give you an idea. This is my engineer driving it about to perform a brake test.
    [video=youtube;gV7U9fffI9M]https://www.youtube.com/watch?v=gV7U9fffI9M&list=UUoFgWsHvb5QXMmtRxzEQBxQ[/video]
     
  2. pmuller9

    pmuller9 Well-Known Member

    Royden

    The cam is actually installed 1.6* retarded.
    As you posted the intake valve does close 76* ABDC using the advertised duration which gives a DCR of 9:1

    The power your engine makes is definitely impressive for a cam relatively small for a 555 cid engine.
    Being able to have a higher compression ratio by using E85 seems to pay off

    I appreciate the info

    Paul
     
  3. slimfromnz

    slimfromnz Kiwi Abroad

    Thanks Paul.
    I had spoken to Chris Skaling and he agreed that it's impressive the power this engine makes with a relatively small cam, small carbs and small primary tubes on the headers. Something works though.
    Mike T told me I should have twin 1050 dominators on this engine and atleast 1 1/8 primary tubes.
    I am so happy with this combo and it's drivability and the imprint of my spine in the back of the seat and the power in a 2800lb car
    Cheers
     
  4. pmuller9

    pmuller9 Well-Known Member

    If we use Slimfromnz's engine as a base line, the Dynamic compression ratio is 9:1 remembering that the engine is all aluminum and is more tolerant to detonation than an all iron engine.

    Typical street performance cams with intake durations in the 230 range close the intake valve around 70* ABDC.
    Putting that figure in a DCR calculator puts the Static compression ratio just under 12:1 for a 9:1 DCR.
    Smaller cams will require less compression so it will depend on what you look at for a cam profile.

    As you can see the cam needs to be selected early in the planning stages.
    This is for a naturally aspirated engine.

    Supercharged or turbocharged has very different requirements.

    Paul
     
    Last edited: Oct 16, 2014
  5. slimfromnz

    slimfromnz Kiwi Abroad

    Here are some vids I took today after being out for a cruise.
    First is in gear
    [video=youtube;cCPwFDMSMlU]https://www.youtube.com/watch?v=cCPwFDMSMlU[/video]

    Cheers
     
  6. slimfromnz

    slimfromnz Kiwi Abroad

    Second one in Park
    [video=youtube;bn6HyWAqA0g]https://www.youtube.com/watch?v=bn6HyWAqA0g[/video]

    Cheers
     
  7. pmuller9

    pmuller9 Well-Known Member

    That's so incredible!
    I never would have imagined that an engine with a cam that has 37 degrees of overlap could idle that smoothly.

    The engine must have monster torque right from an idle.
    That is one fine high horsepower street engine

    Paul
     
  8. slimfromnz

    slimfromnz Kiwi Abroad

    Thanks Paul, it was definately worth the major investment.
    One thing that the Buick frat aren't used to is the 4.5" piston. I think this is a major factor with these tomahawks. When we dynoed this engine, that data was recorded from 4500rpm and the torque curve was on the downslope at 785. My dyno guy reckons it was north of 800.
    The torque is just awesome, from idle to ?
    I haven't spent more than 3 seconds wot in top gear, coz first and second are tyre smoke. All jokes aside, this motor is just the best! Mike T did a fantastic job on the heads, cam selection, comp ratio etc. probably should've gone with the crower steel rod instead of the grp alloy rod.
    It's awesome when cruising in top gear at 60mph and just give it a short burst, then you see 100mph+ on the speedo :Brow:
    Cheers
     
  9. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Agreed!! Must be the compression smoothing it out?
     
  10. 8ad-f85

    8ad-f85 Well-Known Member

    Cubic inches "eat up" cam.
    Good flowing heads tones a cam down, also.
     
  11. slimfromnz

    slimfromnz Kiwi Abroad

    I get a whole 5" of vacuum lol
    Cheers
     
  12. slimfromnz

    slimfromnz Kiwi Abroad

    The heads flow really well right through the lift range. They are a TA CNC all out port job.
    Cheers
     

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