Tuesday, March 4, 2014

Carburator Icing

Yesterday, being the first Monday of the month, was the regular get together of the local BMW airheads group. I guess it's still too early in the year for any other riders but as you can see, even at 6:30pm there is still daylight! On the ride home, I am still loving the extra light from the Denali D1 led light especially with all of the ice on the roads. The warm temperatures over the weekend has made the ice still left on the roads pretty slick.

We generally meet at the Silver Gulch which is one of two microbreweries here in town. There food offerings are typical bar food and it was a little challenging to find anything that sort of fits my diet. I settled for a portobella mushroom burger. Still too many calories and carbs but very tasty. What did we talk about?

http://www.atsb.gov.au/publications/2009/carburettor-icing.aspx
from http://www.atsb.gov.au
I like the ride out to Fox as it is one of the few times when I ride out of town during the winter. Without others to ride with, I generally stick around town during the winter. I'm thinking that the carburetor ice theory is gaining traction. On the way back, there is several miles of modest speed, gentle curving downhill and you can easily tell that the engine was cooling down quite a bit on this run. Prime conditions for carb icing. At least from what I remember when learning how to fly. When I reached the main road, the engine stumbled a bit as it does when ingesting water instead of gasoline. Then it cleared after a short run. I guess I'm just going to get used to this issue when riding at cooler temperatures (+4°F yesterday evening). From the graph, you can see that at low power levels such as down hill runs, there is a pretty wide range of temperatures where icing can occur.

Back when learning how to fly, I was taught to always turn on carburetor heat to control icing when gliding down to the runway for landing just in case you need to reapply full power before touching down or you are doing touch 'n go's.

8 comments:

  1. Insulating them with foam had no effect eh?

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    1. I can't really tell, it isn't that cold anymore. The amount of water now is fairly minuscule by comparison. Only a few drops versus tablespoons.But, no, probably not helping much. George mentioned that he would have used more foam and completely enclose the area from the front of the cylinders to behind the carburetors.

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  2. Richard it's a good thing you enjoy the math and the mechanics involved in the icing problem otherwise you might have been left driving the car like the rest of them. Well done ... Arctic Cowboy! (I feel a new TV reality show coming on.)

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    1. I really do enjoy challenges like this. Nothing happens by magic and I like to be able to figure out problems. Even if there isn't a ready solution, knowing why something occurs means that it isn't a surprise. This sidecar experience has been and continues to be a blast and I even though I haven't been driving the truck much, I have no inclination to get rid of it nor reluctance to drive it if it is the most suitable tool for the job.

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  3. Hmmm I see a potential new Beemer accessory for you to develop, the cold weather carb heat kit!

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    1. I am giving it some thought. Something along the lines of being able to bring warm air into the air cleaner intake kind of along the lines of carburetor heat on a small airplane engine...

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  4. Nice that it is still light out at 6:30. DST will extend that a bit but will be dark earlier in the morning, sigh.

    If you find yourself having another portobello burger when you don't want all the carbs, take the top bun off and eat it open faced or with a knife and fork. Will save you the calories/carbs in half of a bun.

    A few restaurants will lettuce wrap them instead of using a bun too. Red Robin does that and even has vegan Boca burgers. We don't usually go there, but when traveling you never know what you'll be stuck with for options.

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    1. Thank you for the suggestions. I did simply remove the top half of the bun but I think I ended up munching on it anyway. You know how it is when there is just a bunch of folks sitting around talking…

      I will definitely ask for a lettuce wrap instead of the bun next time. I don't think getting these guys will change their location. Something about the beer...

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