65air_coupe

Timing is 12 and 36
Moving fuel line would be difficult, trying other approaches first.
Electric fan has shroud that completely seals to entire radiator surface.
Had the same thought about coolant and just raised it after last drive.
Cap is fairly new and verified as 15 lb....remember, it's not really overheating, no puking never gets over 210.

When I first did this motor/fan configuration, the fan would stay on after the key was turned off IF the temp was over 180*. I was worried about draining the battery so added a relay to prevent that and now I'm going to reverse that change and see what happens. I'll carry a jump pack just in case!

Easy Rhino

Holistically, three types of heat are encountered, conductive, convective, and radiative. Hard to say which is more important to attenuate, and under what conditions.

For conductive, I agree that an insulating material like a phenolic or fiberglass should slow down direct contact heat transfer. That's about all you can do about conduction. Inconel is really no better than iron or aluminum, as it is Nickel-Chromium-Iron alloy - expensive and pretty (a little tedious to work), but only marginally different from any common metal. There are differences about what you can do attenuate each.

For convective, you have to consider both heat rising up through the intake manifold into the carb venturis (when the engine is stopped, at least one intake valve will always be open, probably more, and the core of all the engine heat is open to the carb's guts - no practical way to attenuate). Plus the top of the engine, including things like hot exhaust manifolds/headers, outside of the heat riser on the intake and the mass of the engine block and heads conducting heat to the intake which then convects to the carb, and on it goes.

For radiative, I would argue that this would be the lesser of the three and probably pretty much ignore - or let the actions taken for conduction and convection help what little that they can.

For convection, I would consider the following, most of which have been discussed here:

Use a "Turkey Pan" like the big block AC Cobras - ugly but effective, just find a way to get some cold air in there. If the outside of the turkey pan was covered in radiation-attenuating material, that would be even better. As ugly as the turkey pan setup is, it seems apparent that Shelby found this to the only practical solution to heat in a Cobra engine bay.

Pop your hood while driving and standing still.

Make sure your cooling system is dead nuts on.

If the car is hot when you stop, let it idle until temps drop, unless idling makes it worse.

Block the intake manifold cross-over.

Wrap exhaust manifolds. These may be the biggest heat sources after shutdown (I would check this with an infrared thermometer).

Wrap the fuel lines from the pump to the carb intake fitting.

Maintain your carb in a highly polished reflective state of finish.

Consider every way to get conductive air to flow through your engine compartment.

Just some random thoughts.

65air_coupe

The only comment I would make is that heat transfer through radiation is an issue where distances are close since it's a fourth power function and in this case, that's the fuel bowls and even more critical, the accel pump housing. That's what most all conventional heat shields try to address as did I with my G10 insulator.

Once a non-conductive spacer is under the carb, addressing the convection heat transfer is the remaining action as you state. Doubtful I'll go with the turkey pan route so I'll try leaving my fan to run after the car is stopped and key off and see how I fare.

Easy Rhino

You make a good argument on the radiative heat.

How about a combination of a phenolic spacer combined with a "partial turkey pan", say a sheet of aluminum under the carb that hides under the air cleaner? the front and back area shielding blocking the intake heat and the sides blocking the sides of the intake and the exhausts?

The fellow in Ohio I bought my engine block from, a life-long engine builder and machinist, had an all original '59 fuelie Corvette, with only one mod - he had built and installed a small aluminum shield that fit between the intake valley and intake runners. He swore that was all it took to fix any heat problems in that car.

tbarb

Is your vacuum advance working at idle, how much total idle timing.

65air_coupe

Yes and 12* plus the vac can which I believe is a B28.