Why a heat chamber under carb ?

Unknown
Unknown
edited November -1 in HUDSON
Why the exhaust heat chamber under the carb ? Heat boiling the fuel is often a problem , needing a heat sink under carb to combat it . The cooler the mixture the more gets stuffed in the engine so why is it intentionally heated ? Has anyone ever blocked this off ? If so what was the result . There would still be some heat transfer to the carb thru the metal . . It is also somewhat controlled by the heat riser , which generally has been considered GET RID OF IT , only takes a bit longer to warm up . ALL OPINIONS WELCOMED BUD

Comments

  • hudsontech
    hudsontech Senior Contributor
    Check this out:

    http://en.wikipedia.org/wiki/Carburetor_heat



    Hudsonly,

    Alex Burr

    HudsonTech

    Memphis, TN
  • Unknown
    Unknown
    From the wikipedia article I would conclude that manifold heat directed to the air cleaner intake would be the best setup given the pros and cons for automotive use and I think some cars do use this system with emissions being the benefactor , with no heat anywhere other than under hood temps which get pretty high being enough to have a drying effect on humidity and keep the fuel from forming droplets makeing more power the benifit of a carb engine, other fuel supply systems are another matter of no concern on an old Hudson . Other opinions ?
    Hudson308's last paragraph ---Stock manifolds --The heat riser directs heat to or away from the chamber under the carb, at no time does any exhaust go to the air intake with or without it so I guess you mean the chamber, which is the original questio, block it or let it be as is . My heat riser has been removed with no ill effects . Like to see some more opinions. BUD
  • [Deleted User]
    [Deleted User]
    37 Terraplane#2 wrote:
    From the wikipedia article I would conclude that manifold heat directed to the air cleaner intake would be the best setup given the pros and cons for automotive use and I think some cars do use this system with emissions being the benefactor , with no heat anywhere other than under hood temps which get pretty high being enough to have a drying effect on humidity and keep the fuel from forming droplets makeing more power the benifit of a carb engine, other fuel supply systems are another matter of no concern on an old Hudson . Other opinions ?
    Hudson308's last paragraph ---Stock manifolds --The heat riser directs heat to or away from the chamber under the carb, at no time does any exhaust go to the air intake with or without it so I guess you mean the chamber, which is the original questio, block it or let it be as is . My heat riser has been removed with no ill effects . Like to see some more opinions. BUD



    37,



    I made a plate the same size as the 4 hole gasket between the intake and exhaust manifold last summer. I was having a long crank hot start condition (the fuel was boiing and running into the intake from the hot carbs). I dove it this year in as low as 25 degree weather with no ill affects. The plate cured the hot soak restart problem. As Hudson308 said, the engineers designed it to work at all temps. We don't drive ours in extreme cold as was originally designed. Block it off if you wish.
  • RL Chilton
    RL Chilton Administrator, Member
    Bud-

    Feel free to block it off. Unless you run in really cold weather (like IN can get), you don't need it. It's simply to warm up the car faster, and allow the heater to work faster. Performance-wise, it hampers. Think of an intercooler put in front of a turbo. A turbo moves air faster and forces it into the chambers at a quicker rate. The intercooler cools the air down first, before it gets to the turbo (cold air moves faster than hot air).
  • Geoff
    Geoff Senior Contributor
    Don't ever feed hot air into the carb, you will upset the economy drastically, and cause vapor-lock problems. Hot air is not as dense as cold, and the volumetric efficency goes out the window. Up to 1928 the Essex used a hot-air stove over the manifold, and had a tube going up to this from the carb intake. there were doors you could open for hot weather, but whatever, they ran more efficiently if you took the pipe out, and let the carb suck cold air. In 1929 on all models from then on the heat was applied to the intake via a hot spot from the exhaust. This helped atomise the fuel better, but again, in hot climes, it is better to have no heat.
  • Unknown
    Unknown
    Thanks for the input guys , SHE GETS BLOCKED OFF BETWEEN THE MANIFOLDS , got some stainless to use oughta git er done , any other mod may be a way to pick up cooler air from a source out of the engine compartment, RL is right about intercoolers , one of the best things they did for my big trucks , the old 250's got 3-3 /12 . struglin along. last 500 I had got 7-8 mpg hummin a love song !.. Hey RL, if you don't like the weather in IN. hang around a day or 2 , IT"L CHANGE !! ---- P.S. I'm cousin to the hillbillys in KY, 30 mile from DERBY CITY --northern IN is another story--SNOWBALL ALLEY !!
    BUD
  • RL Chilton
    RL Chilton Administrator, Member
    37 Terraplane#2 wrote:
    Thanks for the input guys , SHE GETS BLOCKED OFF BETWEEN THE MANIFOLDS , got some stainless to use oughta git er done , any other mod may be a way to pick up cooler air from a source out of the engine compartment, RL is right about intercoolers , one of the best things they did for my big trucks , the old 250's got 3-3 /12 . struglin along. last 500 I had got 7-8 mpg hummin a love song !.. Hey RL, if you don't like the weather in IN. hang around a day or 2 , IT"L CHANGE !! ---- P.S. I'm cousin to the hillbillys in KY, 30 mile from DERBY CITY --northern IN is another story--SNOWBALL ALLEY !!
    BUD

    Bud-

    My brother lives in Speedway, about 6 blocks from the track. I've been up there plenty, but try to avoid winter trips (too cold!!). My old man goes up 3 or 4 times a year, usually in his '32 Ford Roadster (has top, but no windows). Makes the race every year, usually visits with AJ Watson, amongst others. Personally, I love Indiana, but not the winters. Lots of car folks there. Last time there, I got to go over and spend some time with Larry Kennedy, next time I hope to see Dr. Doug.
  • Unknown
    Unknown
    RL Chilton wrote:
    Bud-



    My brother lives in Speedway, about 6 blocks from the track. I've been up there plenty, but try to avoid winter trips (too cold!!). My old man goes up 3 or 4 times a year, usually in his '32 Ford Roadster (has top, but no windows). Makes the race every year, usually visits with AJ Watson, amongst others. Personally, I love Indiana, but not the winters. Lots of car folks there. Last time there, I got to go over and spend some time with Larry Kennedy, next time I hope to see Dr. Doug.
    YEAH? I lived just off 16th st there 40 yr ago , did a few yrs in Sprint Cars , got a personal paperback cartoon book Pat Vidan made of me , he was quite an artist, often wonder if the museum would want it. Been to the race many times in the pits and infield as a guest of sponsers . BUD
  • dougson
    dougson Senior Contributor
    Back on track..... so the general feeling out there is that the carb(s) do not need heat to prevent icing in cool to warm weather. This issue has been discussed before. I am going to use headers with a twin-H set up and one source has told me that I absolutely need to heat the carbs. to prevent icing of the mixture. I have seen that the old Edmunds intakes had a hot (radiator) water tube running through them to provide heat, am I wrong?
  • dougson
    dougson Senior Contributor
    Ivan Zaremba used (uses?) this intake on his vintage road-racing Hornet. Although he told me he doesn't drive this car on the street, I would be interested in hearing about his experiences with it, especially if he tried it with- and without plumbing it with hot water. It would also be interesting to hear firsthand about the driveability differences between it and a stock Twin-H setup.[/QUOTE]



    Yes, yes; Ivan, are you out there?
  • Unknown
    Unknown
    DOUGSON , if you haven't , read that WIKIPEDIA article , gives all the pros and cons, different use , etc. That's what it's really all about , what the use and your goal is , power, economy or save the planet , in normal street use I just don't beleive iceing is anything to worry about . I was pretty sure what the consenses would be when I started this but I do like other opinions and expereince , especially with the HUDSON , it's somewhat of a different criter . BUD
  • dougson
    dougson Senior Contributor
    I've read the article, and it bares out what I've always heard before, in cool-warm humid environments (the northeast), during ordinary driving, you need to prevent icing, and heat is the only solution.
  • Unknown
    Unknown
    dougson wrote:
    I've read the article, and it bares out what I've always heard before, in cool-warm humid environments (the northeast), during ordinary driving, you need to prevent icing, and heat is the only solution.
    Just my opinion but I don't really think so , it's pretty dang warm under that hood where your getting your air from , and as I understand it , it is cold air causeing the fuel to form droplets instead of a more vapor form is the problem and I don't think that will happen useing only air under the hood . In an aircraft it's different as the air to the carbs comes from outside at higher altitude which is another matter again , and I think this is what they were dealing with in that part of the article . We are only dealing with normal street use , stock manifolds , no extra long passeges , if the guys raceing with special manifolds were allowed to use a turbo they would not have a problem either as it's not heat but air flow that is their problem . Gotta go with the guys that have had improved results by actual experience , all rhetoric aside . BUD
  • dougson
    dougson Senior Contributor
    I guess I am going to find out one way or another, but it will be some time from now. It was 6 outside this morning and there appears to be no let up predicted for some time. Also, my engine builder, famous for lengthy rebuilds, will probably not have the engine ready until spring, which is actually fine with me. I can squirrel money away over the winter ;).
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