BBC Intake

Discussion in 'Lost PLA casting' started by ka_6772, May 25, 2020.

  1. ka_6772

    ka_6772 Copper

    I'm still working on the LS intake but I also need some help with the BBC one. None of these castings have been made since you guys helped me out with the LS one so these are all cast using my old techniques.
    [​IMG][​IMG]
    Here are a couple more. These two are usable except they had the same issues with some debris. They were all cast inlet down with two styrofoam cups for pouring and as a riser. The one to the right is completely usable and looks like it will take a polish nicely.
    [​IMG]
    Here's a print. I also have some in natural PLA, but it doesn't photograph well. My plan is to put two risers on the inlets to aid in cleaning out the debris. I will use a tapered sprue with the weir-a-majig. Where do you suggest I come into the flange? I had no issues with the injector bungs so I don't want to mess with them.
    [​IMG]
    I finally came up with an airbox I like and started printing it. The clear part is going to be cast or thermo-formed. The spherical bit will be a challenge. The base, rams, loft and throttle body will be cast aluminum.

    [​IMG][​IMG]
    For those who weren't in on the other thread, It's a quad turbo, injected 454 in a T bucket. I started building it in 2001 with a $200 body and $150 454. The first time I drove it was Oct 2015. I pulled it apart for paint in June 2016. I painted it and have been trying to make this stupid intake come to life on and off since then.
    https://www.instagram.com/explore/tags/quadturbot/top/?hl=en

    Thanks,
    Kevin
     

    Attached Files:

  2. Al2O3

    Al2O3 Administrator Staff Member

    So many questions but none of them casting related.....:)

    What ECU and what control scheme for the QuadT?

    Best,
    Kelly
     
  3. ka_6772

    ka_6772 Copper

    I was running fuel and ignition with a Megasquirt 2. I took the VR signal off a late model HEI and fired an MSD box with the MS. This is what I have on all my non LS projects but my turbo 302 Ranger. I built it in 2005 with an MS1. No ignition control. I have a spare MS3 and a Microsquirt. The intake will not allow for a distributor so I got a oil pump drive from an LT4. The Microsquirt will do wasted spark on 8 cylinders. I will probably run it due to its smaller size. I need to make a crank trigger. In wasted spark I won't need a cam position sensor. The MS3 will probably go in the Jag because it has an LS with electronic trans. I believe the Microsquirt can also operate as a stand alone trans controller. I may go with one for the engine and one for the trans because they are cheap and come assembled.

    Kevin
     
  4. ka_6772

    ka_6772 Copper

    This is the motor in my '59. I daily drove this for years with an MS2. No fast idle valve or IAC. I could go outside when it was 8 degrees out, turn the key and it would just fire up an idle at 800 rpm.
     

    Attached Files:

  5. Al2O3

    Al2O3 Administrator Staff Member

    So Speed Density on the QuadT? Was thinking with the air boxes and common IC (or plumb a common inlet?) there may be a place for a MAF.

    Best,
    Kelly
     
  6. ka_6772

    ka_6772 Copper

    Measuring what's coming in makes a lot of sense. I've never played with one using a Megasquirt. Practically everything since '96 or earlier has been MAF. I'm gathering parts to build a turbo motor for my 03 911. I will probably run the stock MAF with an AEM Infinity. I'm also going to cast aluminum intake plenums to replace the plastic ones. That's going to be an interesting one. Lots of thin sections. The plastic one is two pieces bonded or welded together.
     

    Attached Files:

  7. DavidF

    DavidF Administrator Staff Member Banner Member

    Dont think a maf works if over 10lbs boost.
    I'll likely be deleting mine. Still trying to decide on what turbos to run. Thinking gt3582's 3bar map and 110lb injectors and methanol. I feel sorry for the transmission all ready lol..

    I'd gate into the edge of the flange with the runners down and at av45' angle....
     
  8. Al2O3

    Al2O3 Administrator Staff Member

    Why is that? The intake is the usual placement. Many of them recommend placement in a straight with a few diameters of length on either end to help insure laminar flow which can be a packaging PITA. For Kevin and quad turbo arrangement, plumbing four inlets together or running four MAFs is not quite as convenient.

    Of course you a good MAP and temp sensor too but even at a few ATM of boost I just don't think it would matter. The only issue I'd see with any level of boost is just calibration curve but not even sure that is required. MAF's are usually just a piece of heated resistive wire and the change in resistance due to cooling is measured like an RTD. It is strongly correlated to mass flow of air. In automotive applications humidity levels can affect it but that's about it. Dead simple and reliable. If you have a leak on the pressure side at least you're rich. If have a big leak ahead of the MAF, like if your inlet duct comes loose...watch out!

    Best,
    Kelly
     
  9. ka_6772

    ka_6772 Copper

    The MAF usually gets eliminated in aftermarket boosted applications. It's just easier to measure elevation at key on and use a MAP. I was looking at a plug and play for a Lotus last night. It just retains the MAF for IAT.
     
  10. ka_6772

    ka_6772 Copper

    I'd gate into the edge of the flange with the runners down and at av45' angle....[/QUOTE]

    How do you recommend I vent it for clean out?
     
  11. DavidF

    DavidF Administrator Staff Member Banner Member

    How do you recommend I vent it for clean out?[/QUOTE]

    The geometry on this one has you pretty limited
    I'll think about it for a bit longer, but think you will just have to make do...
     
  12. DavidF

    DavidF Administrator Staff Member Banner Member

    There is only so much current you can send to it.. eventually you run past what it is capable of handling...
     
  13. DavidF

    DavidF Administrator Staff Member Banner Member

    This guy explains it better than I can..
     
  14. Al2O3

    Al2O3 Administrator Staff Member

    ....not really. That discussion is all in the context of adding boost (changing a pulley on an OE supercharger for example) to an OE control system and set of OE sensors (in a TransAm according to the guy). The problem he is describing is exceeding the limit of the specific OE MAF and the ECU's ability to read/signal/control the MAF above a given mass flow and power level.

    It's not a problem for an aftermarket ECU and a MAF spec'd for the desired flow/power range.

    Carry on ;)

    Best,
    K
     

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