Escorts could only stay with bombers for 20-40 minutes?

[Vraciu]

To cool the radial engine instead of air. Allowing it to go from this...

(Image removed from quote.)

To this.

(Image removed from quote.)

So they've basically converted it to a hybrid air/liquid cooling.

The lack of a spinner on production F8Fs was primarily to save weight as I understand it. 

[GScholz]

The water/alcohol mix is used to cool the oil.
http://www.airspacemag.com/flight-today/how-reno-racers-keep-their-cool-16828199/?no-ist=&page=1

Cool, and I've also learned Rare Bear wasn't the F8F Darryl Greenamyer flew either. His plane is in the Smithsonian now.

[DaveBB]

So, the evaporative cooling system would be totally impractical for combat. Back to the P-51's awesome jet air-pump radiator that no other WW2 plane came close to replicating.  Sure, the 109 had some junky little radiators in its wings, but how much thrust did they produce?  The P-51 was not a high horsepower plane compared German aircraft or even US radial engine planes. It only produced 1470hp at max power.

[GScholz]

Lol What a troll. The P-51D's Packard V-1650 Merlin produced 1725 hp on WEP, almost identical to a 109K-4's DB 605DB.

[MiloMorai]

Lol What a troll. The P-51D's Packard V-1650 Merlin produced 1725 hp on WEP, almost identical to a 109K-4's DB 605DB.

And slightly more than the DB using 150PN fuel.

Also, one has to be careful, the German PS was slightly higher than HP. ie 1,800 PS/1,775 hp

[Vraciu]

And slightly more than the DB using 150PN fuel.

Also, one has to be careful, the German PS was slightly higher than HP. ie 1,800 PS/1,775 hp

The 109 was a lot smaller than the Mustang. 

[GScholz]

Not really. Not a lot. It's a difference of about 10%.

P-51D
Length: 32 ft 3 in
Wingspan: 37 ft 0 in

Bf 109G-K
Length: 29 ft 7 in- 91% of P-51D
Wingspan: 32 ft 6 in - 88% of P-51D

[DaveBB]

Lol What a troll. The P-51D's Packard V-1650 Merlin produced 1725 hp on WEP, almost identical to a 109K-4's DB 605DB.

Site your source. I keep seeing 1470-1490hp for the P-51's Merlin.

[MiloMorai]

Site your source. I keep seeing 1470-1490hp for the P-51's Merlin.

scroll down to page 223 for Fig 24 showing HP.
http://www.wwiiaircraftperformance.org/merlin-lovesey.pdf

[GScholz]

Site your source. I keep seeing 1470-1490hp for the P-51's Merlin.

You can't have been looking very hard. Even the simplest wiki search: "Powerplant: 1 × Packard V-1650-7 liquid-cooled V-12, with a 2 stage intercooled supercharger, 1,490 hp (1,111 kW) at 3,000 rpm; 1,720 hp (1,282 kW) at WEP"

https://en.wikipedia.org/wiki/North_American_P-51_Mustang#Specifications_.28P-51D_Mustang.29

1,490 hp is just MIL or maximum continuous power.

[drgondog]

The 109 was a.) a lot smaller in wetted area, b.) much draggier but total D in pounds was compensated for by the smaller wetted area to offset the 50+% greater CDparasite.

The last round of 109G-10 and K series were about as fast as the P-51D, even with 72" MP and accelerated slightly better intitially from medium speed envelope.

As near as I have been able to find, there is zero NAA 'official' thrust number for the Meridith effect. I spent some energy trying to calculate pressure drag of the radiator, exit velocity of the pass through air through the radiator with coils at 200 degrees F, estimating the mass flow rate of ambient air (at both SL, STP and 25000 feet), and exit velocity out the butt (closed) - assuming no mass flow rate loss and some other factors to 'assume' heat transfer rate into the 'system'.

I could never get more than ~30-40 pounds of thrust. BTW, that is about 30% of Max Exhaust Thrust (axis component) at 67". Then the other side of the equation is to apply the Drag of the Radiator duct, the stagnation Pressure against the radiator to figure out the Net. At 2x10^^ the Cdp for the radiator duct is .0019 (below 100mph). You have to go the CD vs RN to pick the correct CD (reduced) for RN for the velocity you are basing your calcs on.

Lee Atwood's claims of '300' or whatever else he stated was way overstated. You will note that Ed Horkey and Edgar Schmued never backed up Atwood's claims.

[drgondog]

Military Power for Mustang with 1650-7 is at 3000RPM/61"MP, Max Continuous Power is at 2700RP/47"MP - Ditto for later series 1650-3 and as the 1650-9

[GScholz]

We have the best possible 109K in the game, and it is significantly faster than the P-51D on almost the same power. With 100/150 grade fuel the Pony should edge out the 109 though. Pitty we don't have that as perk-fuel or something. Souped up Spits and Ponies would be awesome, even if we could only fly them once in a while.

[DaveBB]

Here's a good article, maybe help get your math straightened out:

http://www.supercoolprops.com/articles/meredith_effect.php

[GScholz]

"By Joe Supercool"