side ports or p port?

Discussion in 'Mazda Rotary' started by slociviccoupe, May 21, 2011.

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  1. May 21, 2011 #1

    slociviccoupe

    slociviccoupe

    slociviccoupe

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    just got some triangle voo doo for free, ended up with a 13b turbo motor out of a second gen fc rx7. Now looking at this to power my vision when i build it instead of subaru power. Well anyways looking for advice on wether on a turbo motor if side ports are adequate or for aircraft use does the eficiency go up as well as hp when the engine is in p port configuration. asking because the money ill be saving getting an engine for free, and not converting a subaru im thinking about the aluminum side housings to reduce weight and help some with wear and cooling. with the side housings i have the option of getting them without intake ports for p port configuration. so trying to figure out what is best for power and efficiency.
     
  2. May 21, 2011 #2

    Lucrum

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    Peripheral Port

    Here's an explanation on P porting a rotary.
    I elected not to port mine but added an over sized turbo instead.
     
  3. May 21, 2011 #3

    slociviccoupe

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    i know what p porting is and what it does, im just interested for aircraft use and with a turbo if it is needed. when and if side ports are adequate. i know there is blow back problems with p porting and has to have an intake box, but this is for n/a p port rotaries, don't know if these problems exist with a turbo rotary.
    i know p porting is the best way to make power but what does it do with effiency? and could a street port on the side housings with a turbo make adequate power.
    Im already going to be over powering the plane but thats not always a bad thing. plane is capable of firewall forward using a o-320, and recomended with corvair power.
     
  4. May 21, 2011 #4

    Lucrum

    Lucrum

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    How many HP are you looking to achieve?
     
    Last edited: May 21, 2011
  5. May 21, 2011 #5

    slociviccoupe

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    180-240 plane calls for 100-160hp, can support a o-320, designed for corvair power. Im prety sure side ports with a street port intake and exhaust will put me in the power band i want.
     
  6. May 21, 2011 #6

    Lucrum

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    If 160 HP is all you're looking for P porting should not be necessary. In fact it it's turbocharged you'll likely get more than 160 HP as is.
     
  7. May 22, 2011 #7

    Vigilant1

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    And you can drill/seal your own p-ports without buying the AL side housings, if you want.

    The "downside" to p-porting comes mainly with car use (poor idle, etc). There's very little downside to p-porting an acft motor, it's the cheapest, lightest, and most reliable way to get more HP for an airplane application. The turbo a great answer for applications that need the power but (IMO) is overkill for a Vision. But, let us know how it turns out. As you probably know, the RX-7 turbo has not proven reliable in acft use (mismatch in turbine/compressor for this application). What model of turbo/compressor are you planning to buy? There's been a lot of work on this, Dave Leonard has learned a lot of things (and had some hair-raising "lessons") and now has a well-running 13b Turbo setup in his RV-6.
     
  8. May 24, 2011 #8

    slociviccoupe

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    def not using the oem rx7 automotive based turbo, will most likely be using either precision turbo and engine, garrett, or turbonetics. turbo will be sized for the power rating exhaust back pressure and compressor size. will also be true dual ball bearing shaft support. the compressor map will optimized for the continuous hp at the given rpm. Will also be getting a turbo with an inconel exhaust wheel to help with the heat issues. im most likely going to go with the side ports just because there are intake manifolds that bolt on and not using silicone couplers. also using un molested rotor housings no problems with coolant leaking into the combustion chamber, or no common p port issues. do a simple aluminum housing build with stock rotor housings ported, a side draft manifold that wraps over the engine and a set of ida style throttle bodies instead of carbs.
    hopefully be able to run the turbo header under the engine to the turbo mounted underneath, the intercooler down low or on the side and the intake manifold wraping over the engine completing the plumbing. engine will most likely be setup with a dry sump system so oil scavengine from the turbo mounted below the engine won't be a problem.
    im sure im forgeting a few things. actually most likely a lot of things.
     
  9. May 24, 2011 #9

    Vigilant1

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    Should be a fun project. Do correspond directly with folks who have installed and run turbos in their 13B aircraft. IIRC (check this, working from memory), there have been problems with turbo overspeeds when turbine/compressors optimized for cars were used. Thinner air at 10K+ ft MSL results in a very lightly loaded compressor. Combine this with high throttle settings = very high turbine speeds. Might be okay for a short while, but not for extended use. But there are guys who are flying turbos very successfully. The Wankel needs to breathe, and if you push air in it will produce a lot of HP reliably.
     
  10. Jul 26, 2011 #10

    SHIPCHIEF

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    I selected a turbo to assure I get at least 200 HP for my RV-8. I also wanted to use it to attenuate the exhaust blast. a muffler sufficient to survive and quiet the engine would weigh nearly as much as a turbo (In my opinion) I used a fairly large Turbonetics 60-1.
    I didn't go P Port because I don't think it's compatible with a turbo, too much exhaust/intake overlap. Also, I think it's overkill.
    Although I've been rethinking that for my next build. A nauturally aspirated P Port, with fairly tame timing might be OK.
    I'm excited about installing the fuel injector directly to the top of the rotor housing like the 16B concept engine.
     

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