Thanks, 4x4Cruiser for your reply.
I searched the internet under 'gas vaporizing' and you know I somehow ended up with this post reply.
Can someone please tell me what the point of heating the intake manifold with coolant through the heater hoses is? I understand that the older cast iron intakes got heat from being bolted to the exhaust manifold, but why heat them at all? It seems to me that this would make vapor lock more likely on hot days. Is it some kind of emisions thing?
It's kinda a thermodynamics type of issue and view. If you heat the intake to approx 195F Thermostate, the fuel / volatile gas will evaporate, flash off, and STAYS in atomization. Without heated intake the fuel would puddle, thus hard starts and issues in general. The unheated jacket is cool to touch when the fuel first starts to evaporate. Evaporation is a cooling process.
There are TWO heaters the WATER Jacket and the electric porcupine heater under the carb. Both are very important. There are also issues with the radiator hoses and that some of the molded jeep hoses are not available anymore. The entrance & exit intake manifold radiator hoses have a BIG ISSUE if the LOOPS are too high the air bubble will
slow the water flow.
Poor heat for vehicle
Lower heat for the manifold if there are air pockets
Hot summer temps may not have enough cooling.... The intake and heater core and even the rubber hoses themselves are all heat dissipation devices.
The Cast Iron Manifold are bolted together and that does trans heat. There is also a trap door for hot air directions in the exhaust manifold with a BiMetal spring that opens and closes the flapper with them of the manifold.
So if you follow the sorry long story .... the coolant, engine temps, hoses,
water jackets, electric heater all work together... if they have faults or issues. The auto will not run well.
THAT'S IT.
I did think of gases, but I do now. Also, there was a post about getting coolant to the #6 cylinder to avoid overheating and gasket failures.