Alternate BBC OVAL PORT intakes

Discussion in 'Intake Systems , fuel systems and related' started by Grumpy, Aug 29, 2017.

  1. Grumpy

    Grumpy The Grumpy Grease Monkey Staff Member

    the edelbrock https://www.summitracing.com/parts/edl-5061/overview/make/chevrolet
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    is your best option with that hood clearance issue, its easily worth a few extra hundred rpm and maybe 12-15 extra hp and takes about 20 lbs off the car.
    removing the divider wall in that O.E.M. cast iron intake plenum does little but reduce the off idle torque

    I doubt youll notice any negative results if you go with that torquer intake, the fact that the
    edelbrock intake design has a common plenum designed to flow better than the stock intake,
    should help the EFI on that larger displacement..noticeably

    my brother-in-laws swapped from the factory cast iron intake to that intake on his 1974 BBC,
    low compression 454 and while it failed to provide a huge power boost
    its maybe 15 hp increase was a marginal improvement he felt happy with,
    and it removed a good deal of weight and looks noticeably better than his old rusted intake did.
    he had the same hood clearance issue on his 1974 corvettes and did not want to change the original hood.

    probably more related to well worn valve springs than much else, a new set of beehive valve springs,
    of the correct , seat and open load value and the smaller and lighter weight retainers they use should correct that issue.
    this thread should be in MUSCLECARS ENGINE section, do you have any problem if I move it and maybe some of your other conversations concerning parts,there?

    http://www.superchevy.com/how-to/corp-0509-beehive-cylindrical-valvespring-info/

    http://www.flowtechinduction.com/pac-1520-big-block-beehive-valve-spring/

    http://www.superchevy.com/how-to/engines-drivetrain/0703ch-valve-spring-tech/

    http://www.racingsprings.com/Beehive-Valve-Springs


    THE edelbrock intake design has a common plenum
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    designed to flow better than the stock intake,
    should help the EFI on that larger displacement..noticeably

    remember the stock intakes split level plenum won,t work as well with the EFI
     
  2. Mark Bradley

    Mark Bradley Da guy in Newbury

    Time will tell if I made the correct choice although after calling BRODIX I just pulled the trigger on the low profile dual plane "HV2017-r" from BRODIX.
    It is the Dual Plane oval port CNC port matched manifold that matches my heads specifically and has a RPM range of 3000-6800.

    I measured the existing manifold and it has a sloped carb base measurement of 4.8125" (rear 5.375" & front 4.250"). The HV2017 has a flat carb base at 5.175".
    I am anticipating since my 14" air cleaner will now be flat rather than sloped the slight increase (0.3625) in the middle will be fine and the high point (5.375") at the rear of the existing is taller than the new (5.175").
    The reason why I did not choose the Edelbrock is I wanted to avoid an open plenum if possible since I drive this car daily.
     
  3. Grumpy

    Grumpy The Grumpy Grease Monkey Staff Member

    thats a common assumption based on the effective operational rpm band of most open plenum single plane intake designs,
    but the low profile oval port intake has a rather small plenum in comparison and while it is a single plane intake its designed to operate in the nearly same rpm range as you listed
     
    Last edited: Aug 30, 2017
  4. Mark Bradley

    Mark Bradley Da guy in Newbury

    Dammit I hate being common!
     
  5. Grumpy

    Grumpy The Grumpy Grease Monkey Staff Member

    let us know the details of how it fits and functions once its INSTALLED AND TUNED

    btw your ANYTHING BUT COMMON,
    if your taking the effort to do accurate research BEFORE,
    you start buying and assembling parts
     
  6. Mark Bradley

    Mark Bradley Da guy in Newbury

    Well the new BRODIX HV2017 manifold arrived from JEGGS today ($440.00). Not really impressed with the finish work and I AM GOING TO CALL BRODIX. They spent the time to CNC cut the ports to match my BRODIX heads but they left the flashing inside the plenum. It is a "Dual Plane" although there is not divider so it may as well be an open plenum with two floors.
    I'll clean it up but REALLY!!!! For what this thing costs the airpath finish should be tidy.
     
    Last edited: Aug 31, 2017
  7. Mark Bradley

    Mark Bradley Da guy in Newbury

    Well the installed height is identical so there are no clearance issues.
    I'm going need to give it a little time for the ECU remap if needed.
    A very interesting observation is that the intake ports are so different that BRODIX does not use the bolts above/between the runners.

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    Last edited by a moderator: Sep 2, 2017
  8. Mark Bradley

    Mark Bradley Da guy in Newbury

    Let me just say "what a difference" the manifold made. The proof will be in the Dyno results but it will be a few weeks before I do that again ($$).
    I expected to get a little bog off idle because of going to a dual plane without the separator.
    Because I use Electronic Fuel Injection it is simple to modify the fuel delivery on the fly.
    I simply dialed up the systems Accel setting and sensitivity to TPS so that it over comes the bog.
    OMG this manifold changed my motor beyond my expectations.
    I had installed Dunlop W rated tires previously and could not break them lose from a roll... ultill today. 20mph stabbed the throttle and they busted lose without hesitation.
    I do see my vacuum is now MUCH lower at idle.

    Time will tell.
     
  9. Grumpy

    Grumpy The Grumpy Grease Monkey Staff Member

    yes that single plenum design works better with most EFI systems
     
  10. Mark Bradley

    Mark Bradley Da guy in Newbury

    I think the debate as to whether EFI likes single plane or to a dual plane will probably be raging for a long time.
    The value for me is the flexibility it provides day over day can't be touched by a carb.
     
  11. Grumpy

    Grumpy The Grumpy Grease Monkey Staff Member

    yes thats true enough, but a centrally located throttle body and injectors is a bit similar to a carb in that the runners flow a fuel/air mix, so any turns in the runner at least in theory restricts potential max flow and potentially allows some fuel to drop out of the air flow, as it impacts the runner walls
    while mpfi with a dedicated fuel injector supplying every individual cylinder. is even more consistent
    a dual plane design plenum effectively divides the engine into two 4 cylinder engine operating in the same block on the same crank,this has well documented advantages in the lower and mid rpm ranges but tends too restrict upper rpm power
    [​IMG]
    an engines Torque peak is almost always very closely related to the point in the rpm curve where the most effective/efficient cylinder fill, cylinder fill is related to both intake port cross sectional area and exhaust scavenging,efficiency, and is limited by port stall, and cam duration in relation to displacement, compression and valve train stability, ...all factors are easily calculated
    a spit dual plenum tends to increase air speeds but restrict max flow rates at peak rpms and certainly has less consistent flow rates between individual runners,
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    a single common plenum allows all air flow through the throttle body to supply all runners equally
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    useful RELATED INFO you might want to read

    http://www.wallaceracing.com/runnertorquecalc.php
    calculate horse power from intake port flow rates
    http://www.wallaceracing.com/calcafhp.php

    http://www.wallaceracing.com/calchpaf.php

    http://www.wallaceracing.com/ca-calc.php


    http://www.wallaceracing.com/max-rpm.php

    http://www.wallaceracing.com/lpv.php

    http://www.wallaceracing.com/chokepoint.php

    http://www.wallaceracing.com/chokepoint-rpm.php

    http://www.wallaceracing.com/area-under-curve.php

    http://www.wallaceracing.com/piston-speed-velocity.php


    http://www.wallaceracing.com/header_length.php

    http://garage.grumpysperformance.com/index.php?threads/can-you-get-there-with-tpi.10494/#post-44284

    http://garage.grumpysperformance.com/index.php?threads/c4-larger-intake-runners-l98-tpi.13785/

    http://garage.grumpysperformance.co...m-dyno-results-and-other-info.433/#post-37683

    http://garage.grumpysperformance.com/index.php?threads/hey-grumpy-do-i-need-bigger-injectors.5583/

    http://garage.grumpysperformance.com/index.php?threads/port-speeds-and-area.333/

    http://garage.grumpysperformance.com/index.php?threads/ideal-tpi-build.12203/

    http://garage.grumpysperformance.co...sure-hurting-your-combo.495/page-2#post-35063

    http://garage.grumpysperformance.com/index.php?threads/a-caveat-about-profiler-cylinder-heads.10065/

    http://garage.grumpysperformance.com/index.php?threads/a-well-designed-c4-exhaust.786/#post-57392

    http://garage.grumpysperformance.co...ther-efi-intake-manifold-info.431/#post-32491

    http://garage.grumpysperformance.com/index.php?threads/tpi-throttle-body-size-48mm-52mm-58mm.546/

    http://garage.grumpysperformance.com/index.php?threads/sources-for-tpi-parts-and-info.590/

    http://garage.grumpysperformance.com/index.php?threads/bits-of-383-build-info.18/

    http://garage.grumpysperformance.com/index.php?threads/my-current-corvettes-383-combo.430/[/quote]

    http://www.permatex.com/products/Au.../Permatex_Super_300_Form-A-Gasket_Sealant.htm

    http://garage.grumpysperformance.com/index.php?threads/my-current-corvettes-383-combo.430/

    a runner that flows only air ,and has an individual fuel injector fogging fuel into the cylinder head port rather than having the fuel mist in the plum being carried by the air flow into the manifold ports can be more consistent,and the most tuneable versions (individual stack injection) allow the tuner to change the intake runner length to maximize the inertial pulse strength and frequency to maximize cylinder fill rates by matching the exhaust scavenging timing
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    http://garage.grumpysperformance.com/index.php?threads/tuning-a-tunnel-ram-intake.5175/#post-67680

    http://garage.grumpysperformance.co...spacers-and-related-intake-modification.1038/

    http://garage.grumpysperformance.com/index.php?threads/cooler-denser-air.8961/#post-67811

    http://garage.grumpysperformance.com/index.php?threads/porting-can-help.462/page-3#post-67187

    http://garage.grumpysperformance.co...ical-constant-flow-injection.4502/#post-61276

    http://garage.grumpysperformance.co...ed-flow-and-its-limitations.11100/#post-49467

    http://garage.grumpysperformance.com/index.php?threads/calculate-fuel-injector-size.1200/#post-4041
     
    Last edited: Nov 4, 2017
  12. Mark Bradley

    Mark Bradley Da guy in Newbury

    It has been a week or so now and it is time to check how the EFI has adjusted.
    The off idle start had been a little difficult since changing to the new manifold. Idle vacuum dropped from ~10" to 7.5". Cruise (2400 to 3000) vacuum does not seem to be much different from before.
    I used the EFI logging to conduct a few experiments on the performance around drivability.
    The tests were..
    Cold start - warmup
    Casual stop sign roll away
    Casual gear climb
    Flat 1 minute cruise
    Passing lane acceleration (same gear)
    Deceleration with engine brake (no brake, lift foot off the throttle).
    IMG_0914.JPG
    The image above is a warm up cycle and the key is the IAC. This is the equivalent of adjusting your idle circuit and EFI changes it for me as it warms up. An ideal IAC would be between 3 & 10 when warm.

    IMG_0915.JPG
    This is the chart of the cruise followed by a moderate and brief acceleration. The key is general consistency of AFR target vs measured at cruise.

    IMG_0916.JPG
    This would be my passing lane change test followed by deceleration.

    IMG_0917.JPG
    In the last image I know it is pretty busy but there are a lot of points of interest. The two orange circles just indicate fluctuation between desired vs measured AFR at some noisy points.
     
  13. Grumpy

    Grumpy The Grumpy Grease Monkey Staff Member

    looks like your getting things under control, what is your general consensus,
    as to the intake change and the resulting changes youve seen,
    and potential power gains and drive-ability,
    your experimenting over lower,rpm, mid rpm, and peak rpm power?
     
  14. Mark Bradley

    Mark Bradley Da guy in Newbury

    I won't have hard numbers until I take it to the Dyno maybe 30 days or so.
    Overall I am happy from a drivability perspective. Initially the early bog was a concern. Fortunately tuning with EFI is so much easier than jets and squirters.
    Having REAL data to work with is great.
     
  15. Mark Bradley

    Mark Bradley Da guy in Newbury

    Stil have not made it to the dyno although I figured out the cause of my low vacuum. Rather humbling to be honest.
    I had two failing spark plugs and I dismissed them because they only had a hundred miles or so on them. Fortunately by habit I change plugs more often than most people and I save my previous set. It was clear that one plug on each side was soot covered. In with the spare set and the vacuum came up.
    See folks... this is what happens when we say “it can’t be that because they are new”.
    Generally the bottom end is still a little soft but 3000 plus feels much better.
    It is almost trivial to over power the tires so rolling into the throttle is amazingly fun.
    I have spent zero time with tuning although I will and can probably help some of the low end with some more fuel... logs will help.
    Cheers.
     
    Last edited by a moderator: Oct 29, 2017
  16. Indycars

    Indycars Administrator Staff Member

    I don't know about you, but I have to re-learn this one every so often. :cool:
     
    Mark Bradley likes this.

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