Viewing 15 posts - 1 through 15 (of 17 total)
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  • #85281
    ccochran1
    Participant

      TTCF Folks

      Can I get a recommendation for my twin cessna 310k how to hot start. Cold engine starts are immediate prime and she pops to life. Hot engines are a terrible. I appreciate the help.

      Chris

      #106557

      There are two hot start methods that I use.

      Typical hot start:

      -Prime as normal for cold (everything forward, primer on about 3-5 seconds)
      -Start cranking with everything full forward. Pull throttle back at a rate that would get to idle cut-off in about 3 seconds while cranking
      -By the time you get about 2/3 of the way down, it should catch
      (sometimes this works better with the mixture pulled back about 1/2-1″)

      Flooded hot start:

      -Engine’s flooded (by accident or on purpose)
      -Mixture at idle cut-off, throttle/prop full forward
      -Start cranking, when it catches move the mixture forward and the throttle back. Timing for those actions will take some practice, and I usually have to let it run for about 1/4-1/2 second before moving the mixture or it will flood again

      Also, make sure your ignition system is in good shape and that your starters and starter cables are working well. An engine that cranks fast with a good spark will be much easier to start than an engine that cranks slowly with a bad spark.

      I’m not that far away from you, so if it gets really difficult, fly over here and we’ll do some practice starts. πŸ™‚

      #106561

      Try this method first:
      Full rich(do not prime)
      Apx 1″ of throttle
      Start button and supplement with fuel primer once the engine fires until engine is running smoothly
      Works about 80% of the time for me and engine starts in 1-2 rev.
      Jon

      #106562

      Jon’s method works best for me. If it fails, just wait a few minutes and try again being conscious of how much you prime, don’t prime and flood the engine.

      #106564

      Turn off your engines w/ your fuel selector valves. This eliminates fuel vapor. This works a major majority of the time for me. Then again you will come across an engine or two that has a mind of its own.

      #106565
      quote CMorehouse1:

      Turn off your engines w/ your fuel selector valves. This eliminates fuel vapor. This works a major majority of the time for me. Then again you will come across an engine or two that has a mind of its own.

      The issue with mechanical fuel systems like ours is that they will all be slightly different because of variances in manufacture and wear of components. Electronic systems really do a lot for reducing variation.

      #106566

      I use Ted’s 2nd suggestion when having any difficulty:

      -Mixture at idle cut-off, throttle/prop full forward
      -Start cranking, when it catches move the mixture forward and the throttle back. Timing for those actions will take some practice, and I usually have to let it run for about 1/4-1/2 second before moving the mixture or it will flood again

      Has worked every time for me.

      Shelby

      #106568

      That second option works great on all injected Lycomings, by the way. Only different for the injected Lycos is to leave the electric fuel pump on while cranking.

      Hot starting an injected Aztec is supposedly hard, but isn’t if you use that method. πŸ™‚

      #106569

      With practice, I was able to hot start my Aztecs quick enough that people looked at me funny. One guy thought I had some kind of electronic fuel injection. All it takes is practice and familiarity with your airplane and each engine. I’m sure I’ll get to that point with my 340. I’ve already discovered which engine I need to scowl at in order for it to start!

      #106570

      Yep, that’s how I was with my Aztec. Hop in, all forward, both fuel pumps on to prime at the same time, left engine in a couple blades followed immediately by right engine. I got funny looks for being in the air before most people had their engines going.

      #106571

      A day giving air rides will teach you a lot about hot starts.

      I once had a student who just didn’t get hot starts. He’d been studying density altitude and aircraft performance and a light bulb in my head went off and after we’d landed I asked him “What do you think the density altitude inside that engine is right now?”

      “Wow, it’s pretty hot in there, I’d say it’s pretty high”

      And, what about that hot air?

      “Oh, it’s really really thin. Not much air in there.”

      Ok, so how much fuel are you going to need to obtain the correct mixture?

      “Oh about…. nearly none!”

      bingo. problem solved.

      #106572

      Hmm,
      my soloution to hot starts, which I anyway only exercise when I need to refuel for continuation of my trips to my destination, is:
      I turn of my engines by switching off the ignition and leaving my boost pumps set to low.
      (Yes, I know it might be dangerous to toutch the props or to come close to them…)
      For starting the engines again, I press the start button and maybe flip the boost pump a little to high once the engine fires.
      This works for me almost every time after one or two blades.
      If not, I use the hot start sequence which is tought in the seminars.
      (Throttle closed, Mixture cut off, Boost pump high for 90 seconds. Then normal cold start.)
      Thomas

      #106620
      ccochran1
      Participant

        Guys
        Many thanks for all the inputs! Will be about a month before I get to try any starts, new engines are being installed and the project began today! I’ll keep everyone posted

        Many thanks
        Chris
        KBMI

        #106705

        Agree with Ted, but before you hit the start button, with the throttle and prop full forward, mixture in cutoff, run your boost pump for 30 seconds. This cycles cool fuel through the system.

        I then move mixture to full rich and start immediately, it should light off. Be ready to pull the throttle back to 1000 RPM.

        Just another technique.

        Butch

        #106752

        Been getting a little practice (and funny looks) at hot starts on my 310 while preparing for my multi checkride. She is finicky and I haven’t found the fail proof method yet, always has to be someone standing close by too… πŸ˜†

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