Re: 55-56 Heat Riser

Posted by 55PackardGuy On 2010/9/27 22:19:35

The heat passages through the intake can also be blocked closed by carbon. Especially important on dual exhaust systems where the "flapper" in the exhaust manifold still works and shuts off the flow, like it's supposed to. Exhaust gases that were meant to pass through the ports in the intake from the blocked side to the open manifold have nowhere to go. Makes the car run kinda funny.

The automatic choke will eventually pull off without the heat riser, from either warming coolant or electrically generated heatl, depending on the type. Cold driveability will suffer, as well as mileage, during warmup, as intake mixtures hit the cold manifold and the fuel condenses. These gadgets are there for a reason.