Cool Weather Driving

[55 Fargo]

Hi all, no snow here in Manitoba, at least in the south where I live. It is a very sunny 24 degrees f this morning, the wet gravel road is frozen, so it was time for a cruise in the old Chrysler.

It started well, on the road it ran without any hesitation, this leads me to believe the choke is working well, and the heatriser, that is stuck, is stuck in the cold position.

When the weather is warmer, after a 5 to 10 mile run, when you shut off the engine and go to turn it back on, the carb, seems like it is fuel starved at first. This leads me to believe the gas is being heated up in the carb bowl, could this happen?

I am sure that having the exhaust circulate in the manifold, instead of exiting out freely, must have some effect on the fuel vaporization, engine performance, even the temp of the engine itself.

I plan to take off the manifolds this winter, not sure if I will repair the heat riser, or eliminate it all together.

Have any of you experienced any of these symptoms............Fred

[greg g]

The heat riser's purpose was to heat the intake manifold. the warm surgace the prevents the fuel air charge from condensing and reforming droplets on the cold metal. We all know liquid fuel doesn't burn very well, and keeping fuel in vaproized form is hard at colder temps. When it is cool during the day, say in 4 to 8 degree range, the fact that the flap is stuck, probably doesn't make much difference. You are getting the benefit at cold temps, and it likely isn't causing any problems because it fails to close.

I have mine welded in the closed (no heat to the manifold) position and since I only drive during the summer months here it isn't a factor. I will occasionally drive with the temps near the freezing mark and when the engien gets up to temp I have never encountered a problem.

I think it has been discussed that the position of the heat riser has very little effect on engine operating temp or performance. Keep soaking it with penetrant and keep putting it through some heat cycles, and give it some affectionate whacks with your favorite bashing device (percussive maintanence) and hopefully it may free up. but in the meantime, don't obsess over it. Drive that thing!!! Gotta admit frozen gravel (next to a frozen lake) is my favorite surface to drive on. 100kph on dirt is such a hoot!