Yet another ‘Flap’ question.

Discussion in 'Mech Tech' started by Soggz, Jul 14, 2023.

  1. Zed

    Zed Gradually getting grumpier

    You could set up anything to fail if you tried, didn't pay attention or made assumptions.

    Watch the video I posted. The guy has read to coat bearings with assembly lube. Start at a bit past 6 minutes. He reminds me of you. You read with your brain switched off.
     
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  2. Soggz

    Soggz Supporter

    Sticks and stones, old man…sticks and stones.:thumbsup:
     
  3. Soggz

    Soggz Supporter

    And you feel the need to apologise to everyone…:D:lol:
     
  4. I missed the link?
     
  5. Soggz

    Soggz Supporter

    On a different thread …
     
  6. Soggz

    Soggz Supporter

    ‘Get Out More’
    Wish I could stay in more….:p;)
     
  7. My ghia has no thermostat and no flaps in the fan housing. It was like that when I got it.
    Makes it a right pain to start from cold, you need to nurse it to keep the revs light while she warms up, and not give her too much gas so as not to thrash it while the oil warms up.
     
    Soggz likes this.
  8. Getting a stat and all the flaps and connecting rods is 'on the list' :rolleyes:
     
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  9. Soggz

    Soggz Supporter

    Are you looking for a set of flaps? I may know of some, but don’t count on it, as you only just said…
     
  10. If they are for a non-doghouse fan shroud, then yes I am. The ghia is a 1500 single port.
     
  11. Soggz

    Soggz Supporter

    Not sure…I’ll ask the guy. Won’t be next week though.
     
  12. There's no rush :thumbsup:
     
  13. Rich83

    Rich83 Supporter

    Flaps or no flaps will have zero effect on starting from cold. I'd look elsewhere for your issues starting from cold
     
    Last edited: Jul 15, 2023
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  14. So what's the thermostat and flaps for, if not to reduce cooling until the engine is warmed up properly?
    I didn't mean it wouldn't turn over and fire up, it does that fine every time. It just takes some warming up before trying to pull away, because it's being cooled from the word go.
     
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  15. They are for that very purpose. Just like a watercooler.
     
    77 Westy likes this.
  16. 77 Westy

    77 Westy Supporter

    That's what I thought you meant but what you said was - 'Makes it a right pain to start from cold' :)
     
    Last edited: Jul 16, 2023
  17. mikedjames

    mikedjames Supporter

    There are two phases to the warm up.
    The first part is the "drag racer" bit where the engine block is cold and the cylinder heads begin to warm. At this point your engine will run happily for several minutes without a cooling fan. There is no need for cooling because the heat can be stored in the metal of the heads and pistons and cylinders. Drag racers using T1 derived engines remove/omit the fan belt and/or have engines with billet cylinders and heads with no fins in the extreme..

    At the very beginning the engine spins without a proper oil film on the bearings and so they wear rapidly. Then a short while into this, often while still cranking the oil pressure builds from the oil pump.

    The carburettors are feeding a totally cold engine so you run extra fuel into the cylinders where it washes off the oil ..

    This is the bit where having flaps and thermostat makes NO difference to rubbish starting or having to nurse it by flooding fuel into it either with the pedal or a choke.


    Then you get into the cold engine warmup phase where the engine parts are still cold.

    The engine case has not expanded (as it expands faster than steel) , so bearings are crushed more and wear faster.

    Pistons haven't expanded so are rattling around a bit more than later on.

    This part continues until the cylinder heads are hot and the engine block / oil temperature has indirectly climbed by being heated by the heat from the combustion chambers.
    Then the engine reaches operating temperature and wear slows down.

    In Orange County California, on average the air is warm enough for the cylinder heads to warm up without flaps to the point that the cold engine wear stops after a time. So your cruise to the beach ends with a warmed up engine.

    Over here in the UK it's easier to over cool the engine so it stays forever in the cold to warmed up transition where things are not running as designed and are wearing faster than intended.. Your cruise to the chip shop ends up with a cold engine.

    So the thermostat/flaps reduces the wear on a warming up engine by shortening the warm up time.

    It also indirectly causes the initial warming air from the heat exchangers (which heat fast because the exhaust is providing many kilowatts of waste heat) to come out of the dashboard vents faster because the flaps are closed, increasing pressure in the fan housing.

    So not having flaps doesn't change starting, all it does is slows down warming up.
     
    Last edited: Jul 16, 2023
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  18. Soggz

    Soggz Supporter

    That’s sounds more like a flap problem, in a carb. Bi-metallic spring set wrong?
     
  19. Barry Haynes

    Barry Haynes I dance in leopard skin mankini’s

    Mine is a right spurs to start especially when the weather is cold but I have twin 34s with no choke so it’s understandable I suppose :(
     
    Last edited: Jul 16, 2023
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