P51 header tanks: The inside story..

[51fixer]

The 620 and later series heads have a small coolant tube on the front of the head that requires the boxes inserted in the tank for clearance.

Whoever it was that modified the ones for the transport heads/banks needs to learn how to bend sheet metal without resorting to what looks like a Stilson. Everyone one of these I've seen has witness marks about 1/2in from the welds that looks like it was worked on by a plumber.

Most 620/720 series heads and banks that I have seen do not have the pipe to the front installed making the massive modifications unnecessary.
Just a small depression is needed and can be done without surgery.
Rich

[ZRX61]

Most 620/720 series heads and banks that I have seen do not have the pipe to the front installed making the massive modifications unnecessary.
Just a small depression is needed and can be done without surgery.
Rich

Indeed, a swift clout with a suitable mallet has evidently been employed on some of the tanks I've cut in half. The ones with the big box shape welded in were apparently all done at the same place in Florida at some point in the past.

[Bill Greenwood]

The only reason that I can see for having the internal tubing instead of just having the larger hollow chamber might be if they are trying to slow down the flow of steam and compress is so it becomes a stream of liquid again.
Am I right or does anyone know the answer for sure?

I watched one man make a header tank for a Hurricane from scratch out of brass sheet, it took him the better part of a month, but was great looking when done and worked fine.

[51fixer]

Most 620/720 series heads and banks that I have seen do not have the pipe to the front installed making the massive modifications unnecessary.
Just a small depression is needed and can be done without surgery.
Rich

Indeed, a swift clout with a suitable mallet has evidently been employed on some of the tanks I've cut in half. The ones with the big box shape welded in were apparently all done at the same place in Florida at some point in the past.

I know the Canadians installed the 620/720's in Military service and modified the header tanks.

Rich

[b29flteng]

Bill, the pressure and coolant (anti-freeze) keeps the coolant from turning into steam, you don't want steam as it will not absorb heat except under much higher pressure, it works just like your car.

[51fixer]

The only reason that I can see for having the internal tubing instead of just having the larger hollow chamber might be if they are trying to slow down the flow of steam and compress is so it becomes a stream of liquid again.
Am I right or does anyone know the answer for sure?

In a Mustang the Header Tank it serves a few purposes-
1. It serves as a reservoir. But the coolant level in the header tank is at a lower level than what is contained in the heads and banks. But, the coolant won't drain down out of the head and banks.
2- You don't want the coolant level to drain down when the engine is shut down. The individual tubes are sealed to the outlet of the heads and banks but the open end sits in the liquid pools at the 2 lowest points of the horseshoe. The external outlets that connect to the coolant lines leading away from the tank don't directly connect to the tubes leading up to the connections to the heads. This forms a siphon and keeps the coolant level in the heads from dropping when the engine is shut down.
3- The little tubes exit off of the small scroll chamber where the coolant exits out of the head. This deaerates the coolant and removes bubbles which can cause hot spots inside the heads and banks.
Problems develop from cracks that allow air into and can allow the coolant level then to fall at shutdown.
Rich

[ZRX61]

Just found a "before blasting/post detergent" pic, not the same tank as the other pic tho. This one is a couple of years old.