P51 header tanks: The inside story..

[ZRX61]

ok, I lied, no story, just a pic of one that's apart right now.





The oblong *box* shapes under the tubes are where they were modified to clear transport heads/banks. Most header tanks don't have that cut out doohicky

[avenger2504]

Ahh so thats what lives in there. Not just an empty space then. Mind you some oil and fuel tanks have a fair amount of components inside sight unseen once they are welded up. Thanks for posting!

[ZRX61]

Next time I cut one in half I'll get a pic of what a complete mess they are before cleaning. That one has a bunch of welding to be done inside before it gets put back together (lots of cracks & it resembled a shower head when filled with water)... It took quite a bit of media blasting to remove what appeared to be about 20 years worth of Barrs Stop Leak... at least it wasn't *too* caked with oil & scale like most of them are.

[b29flteng]

Doohicky??? Is that a technical term?

It's quite a complicated piece.

[sdennison]

Did all that spent brass come out of it as well?

Seriously, I'd love to know the engineering behind that design. Many times, restrictors like those were meant to slow the water/coolant flow to give time to get the heat transferred from the engine to the coolant. These are pretty intricate shapes.

[ZRX61]

Did all that spent brass come out of it as well?

Seriously, I'd love to know the engineering behind that design. Many times, restrictors like those were meant to slow the water/coolant flow to give time to get the heat transferred from the engine to the coolant. These are pretty intricate shapes.

.45 ACP was me, .22LR was my 12yo daughter out in the desert last week

The design inside the tank is to prevent cavitation (alledgedly). I'm not sure what the inside of the Spitfire version looks like as they are made from brass, screwed & soldered together & look liker a nightmare to take apart...& it's years since I saw one.

The one pictured still required further cutting apart at that point to access the cracks etc before getting down to the TIGgery-Pokery

[John Beyl]

Did all that spent brass come out of it as well?

Seriously, I'd love to know the engineering behind that design. Many times, restrictors like those were meant to slow the water/coolant flow to give time to get the heat transferred from the engine to the coolant. These are pretty intricate shapes.

Hi Scott,

The coolant enters the tank at the top (The two connections in the welded in casting). If you look at the second picture you can see the tube turns into a barrel shape and the small line is welded to the top of the barrel shape. That's a swirl chamber to removed trapped gases and vapor from the coolant. The gases exit through the little tube which is routed to the bottom of the tank so it can pick up coolant and add it to the coolant stream as needed. When properly filled the tank holds two football shaped “pockets” of coolant with open expansion space at the top.

For the B, C models there were two nearly identical versions of these tanks. This is the later version, used on the later B and C and all D, K models which is a little better than the early tanks.

The repairs being carried out on this tank are common! The good news is new built units can now be purchased so an option other than the labor intensive repairs is available.

Jack Roush makes a flow straightener (Not a restrictor) that inserts into the inlets. If the alignment is poor between the bank's outlet spout and header tank inlet (Which it often is), the swirl chamber is a lot less effective. The straighteners are designed to clean up the flow to increase the chamber's efficiency.

John

[ZRX61]

The good news is new built units can now be purchased
John

If you're talking about something from the Norcal area & Romania that deal went tits up.

[sdennison]

Did all that spent brass come out of it as well?

Seriously, I'd love to know the engineering behind that design. Many times, restrictors like those were meant to slow the water/coolant flow to give time to get the heat transferred from the engine to the coolant. These are pretty intricate shapes.

Hi Scott,

The coolant enters the tank at the top (The two connections in the welded in casting). If you look at the second picture you can see the tube turns into a barrel shape and the small line is welded to the top of the barrel shape. That's a swirl chamber to removed trapped gases and vapor from the coolant. The gases exit through the little tube which is routed to the bottom of the tank so it can pick up coolant and add it to the coolant stream as needed. When properly filled the tank holds two football shaped “pockets” of coolant with open expansion space at the top.

For the B, C models there were two nearly identical versions of these tanks. This is the later version, used on the later B and C and all D, K models which is a little better than the early tanks.

The repairs being carried out on this tank are common! The good news is new built units can now be purchased so an option other than the labor intensive repairs is available.

Jack Roush makes a flow straightener (Not a restrictor) that inserts into the inlets. If the alignment is poor between the bank's outlet spout and header tank inlet (Which it often is), the swirl chamber is a lot less effective. The straighteners are designed to clean up the flow to increase the chamber's efficiency.

John

And what of the small rectangular boxes that lay underneath the swirl chamber plumbing?

[John Beyl]

Did all that spent brass come out of it as well?

Seriously, I'd love to know the engineering behind that design. Many times, restrictors like those were meant to slow the water/coolant flow to give time to get the heat transferred from the engine to the coolant. These are pretty intricate shapes.

Hi Scott,

The coolant enters the tank at the top (The two connections in the welded in casting). If you look at the second picture you can see the tube turns into a barrel shape and the small line is welded to the top of the barrel shape. That's a swirl chamber to removed trapped gases and vapor from the coolant. The gases exit through the little tube which is routed to the bottom of the tank so it can pick up coolant and add it to the coolant stream as needed. When properly filled the tank holds two football shaped “pockets” of coolant with open expansion space at the top.

For the B, C models there were two nearly identical versions of these tanks. This is the later version, used on the later B and C and all D, K models which is a little better than the early tanks.

The repairs being carried out on this tank are common! The good news is new built units can now be purchased so an option other than the labor intensive repairs is available.

Jack Roush makes a flow straightener (Not a restrictor) that inserts into the inlets. If the alignment is poor between the bank's outlet spout and header tank inlet (Which it often is), the swirl chamber is a lot less effective. The straighteners are designed to clean up the flow to increase the chamber's efficiency.

John

And what of the small rectangular boxes that lay underneath the swirl chamber plumbing?

Those would be the cut outs for clearance when certain transport heads are used. No sure which require this but our 500 series heads work fine without tank mods.

John

[John Beyl]

The good news is new built units can now be purchased
John

If you're talking about something from the Norcal area & Romania that deal went tits up.

ZX,
I could be wrong but I think Ken McBride might be making them. I know the guys up at Tri-State got a new one about a year ago for a project they were working on. Not sure where it came from.

Bob May just had a load of various Mustang carstings made. Could be he made some of these as well. Lot's of work in that silly little tank, huh?

John

[Hal B]

And what of the small rectangular boxes that lay underneath the swirl chamber plumbing?

Those would be the cut outs for clearance when certain transport heads are used. No sure which require this but our 500 series heads work fine without tank mods.

John

As John says, the 500 series transport heads will clear the stock tank. 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.

[ZRX61]

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.

[Rossco]

Here is a MkV Spitfire one,pic taken from the Avspec site when they restored Marion.

[ZRX61]

Here is a MkV Spitfire one,pic taken from the Avspec site when they restored Marion.

Good lord, I wonder if you could get a tune out of it if you fitted a trumpet mouthpiece?