Engine Icing Up

[bobodu]

You guys kill me!!! Move SOUTH!!! Got no icing here...
Been watching the clowns up North in Michigan falling through the ice....a DOZEN on the East Bay of Houghton Lake so far this year!!

[KE4AVB]

Bob, Icing can occur even in the South. I have personally seen several times here. A couple examples. One time while flying during 90 F weather I had carburetor to start icing over. Not fun at all when over a large city with no place to land. A second more recent time was I mulching up my leaves on a 40F morning and my 310000 series Briggs carburetor iced over.

The reason icing occur is that there is pressure drop in the carburetor and intake. This causes the water in the fuel and the fuel itself to evaporate. This evaporating has a cooling effect and depending on the conditions at the time icing starts occurring. It is same thing that happens in our air conditioners everytime they are operating as it the difference between 250 psi Freon pressure side and 30 psi suction (referring here the the R12/R22 systems here). New systems there is even larger differences.

Oh just thought of another instant where had icing problems and that was my old 73 international pickup. It had a gutted heat riser and it would ice up during the winter months here.