Jim MacDonald wrote:
Great photos as usual, Jack. Do you know what the access panel to the right of the exhaust stacks on Funnyface is for? I've seen it on some P-51B/Cs (incl Shangri-La) but not on others. Field mod? For access to?
Thanks,
Mac
The early B/C model had a method for channeling hot air to the carb to deal with carb ice which could cause deteriorated enginge performance or worse, in extreme cases it could cause the engine to quit. In these early models it had a small door which would open, the door in question, and a duct lead down to the carb air duct below the engine. The hot air behind the exhaust would be drawn in through that small door. There are levers on the rear top of the console on the pilots left side which would actuate the system which also had a plate on the forward end of the carb duct below the engine which would drop down to cut off the air entering from the front. We call this the "guillotine". It would also be used if the filtered air was selected. Cut off the main air source and suck in through the filter box. That air entered through the small side panels with the holes in the lower front cowl and would flow through filters, 1 on each side. This also would reduce the performance of the engine but was utilized during dusty, dirty conditions. After T/O you would select the normal ram air inlet.
I don't know if using warm exhaust air to run an engine was a great idea as this carb heat system was replaced on later aircraft with a door that would open off of the main carb air trunk and it would use warm air from inside the engine compartment. A TO came out requiring the door to be secured and the system rendered inoperable. TO 01-60JD-34 dated March 17, 1944.
Rich