Good video. Thanks for making.
When people think of an engine running properly because it has warmed up, it is the intake manifold that is actually the part that makes the car "feel" warm. You need to have a hot spot under the carburetor to vaporize any atomized fuel that falls out of the airstream when it hits the intake manifold floor. Liquid gasoline will run along the bottom of the intake manifold and into the cylinders to end up washing oil off the cylinder walls and diluting the engine oil Not having a hot spot will also give the car a lean bog when the engine is not fully warm. I do not recommend disabling the manifold heat control system even if you live in Furnace Creek. See
Engine Wear.
Manifold vacuum helps to vaporize atomized gasoline in the intake manifold and absorbs heat in the process. Without a continuous supply of exhaust heat, the intake manifold will become very cold. If you have a problem with carburetor percolation, you are far better off adding insulation (like a phenoloic spacer) under the carburetor to help keep it cool. See
Intake Manifold Heat.
See
YouTube: Down the Gasoline TrailFraso,
I live in SC where temperature dips below 30 degrees only a few times each winter. My plan is to keep the flap in the manifold in the closed position so that the MAJORITY of the exhaust is diverted down. The exhaust can still get through to warm the intake because the flap really doesn’t come anywhere close to making a tight seal.
I spoke to Tom Langdon about this subject. He sells a warming device for people who have converted to headers. His device uses circulating hot radiator coolant to warm the intake. It takes several minutes for any engine to get warm enough to open the thermostat, so at best his device doesn’t add heat for 3-4 minutes.
He said that living in a warm climate like SC, if I keep my flap in the closed position and just wait a minute or two, the heat would build and I’d be fine. That’s my plan. Northern folks need to figure out how to make their heat risers work.
