USN adopts V-12 engines: pros cons?

[Shortround6]

It may, but then it doesn't really offer much over the F4F either. More speed but not the speed of the P-40. Better climb at high altitudes but how much may depend on gun fit of the Hurricane, 8-.303s, 12-.303s or 4-20mm? or ??- US .50 cal? 1400 rounds of .50 cal ammo weigh more than 6000 rounds of .303.
Range/endurance is a problem.

The V-12 powered planes may offer one or two or three advantages in certain areas but as overall packages do they offer enough to outweigh their disadvantages. Including the glycol dislike.

 

[RCAFson]

It may, but then it doesn't really offer much over the F4F either. More speed but not the speed of the P-40. Better climb at high altitudes but how much may depend on gun fit of the Hurricane, 8-.303s, 12-.303s or 4-20mm? or ??- US .50 cal? 1400 rounds of .50 cal ammo weigh more than 6000 rounds of .303.
Range/endurance is a problem.

The V-12 powered planes may offer one or two or three advantages in certain areas but as overall packages do they offer enough to outweigh their disadvantages. Including the glycol dislike.

The Sea Hurricane IIC was faster at all altitudes, climbed much faster at all altitudes and had a lot more firepower - 4 x 20mm cannon. OTOH, it did have less range, but it could carry 2 x 45IG DTs. Combat power of the HSH IIC was 1460HP, which coupled with 10% lower weight than the F4F-4 gave it a rate of climb far exceeding the F4F-4 and was probably similar to the A6M-2-21. Put 4 x .5in BMGs in the HSH and the USN would have had an aircraft with much the same or superior performance as the A6M in every area except turn rate.

 

[Shortround6]

Except the Americans didn't run the Merlin XX/V-1650-1 at 1460hp for some reason. They ran it a 9lbs of boost for 1240hp at 11,500ft and 1120hp at 18,500ft. At least officially.

Speed difference is marginal at times and may even flip flop at certain altitudes between certain models. British data card for a Martlet/Wildcat V calls for 332mph at 21,000ft at "mean" weight. This may very well be high but most F4F-4s should be good for 315-320mph at around 20-21,000ft. Speeds quoted for Sea Hurricanes IIs are all over the map, from 314mph to 342mph. Why the Sea Hurricane with 4 20mm guns and carrier gear should be faster at 21,000ft than a MK IIA land plane with 8 .303s I have no idea.

F4F-4 was tested as faster than a P-40F above 22,000ft. Bad P40-F???

 

[RCAFson]

Except the Americans didn't run the Merlin XX/V-1650-1 at 1460hp for some reason. They ran it a 9lbs of boost for 1240hp at 11,500ft and 1120hp at 18,500ft. At least officially.

Speed difference is marginal at times and may even flip flop at certain altitudes between certain models. British data card for a Martlet/Wildcat V calls for 332mph at 21,000ft at "mean" weight. This may very well be high but most F4F-4s should be good for 315-320mph at around 20-21,000ft. Speeds quoted for Sea Hurricanes IIs are all over the map, from 314mph to 342mph. Why the Sea Hurricane with 4 20mm guns and carrier gear should be faster at 21,000ft than a MK IIA land plane with 8 .303s I have no idea.

F4F-4 was tested as faster than a P-40F above 22,000ft. Bad P40-F???

USAAC testing of the P40F gave speeds of 360-370mph, at ~19000ft, while RAE testing showed 354mph at 20,400ft at 8900lbs.

Typical speeds for a HH IIB and IIC are 330mph at ~20,000 ft, slower speeds are usually with external stores or 2 x 40mm guns, such as the IID at 7600lb.

 

[gjs238]

And they were replaced by the F6F and F4U.

But didn't those have 1-stage blowers?
The 2-stage varients came later.

For example, I thought the F4U-4 was the 2-stage varient.

 

[tomo pauk]

The R-2800 in F6F and F4U was always featuring the 2-stage blower. The F4U-4 was using the C series R-2800, again 2 stage, that was able to give both more power, and at higher altitude.
The only single stage users of R-2800 were the bombers, eg. B-26, A-26, Lockheed Harpoon (B-34).

 

[Shortround6]

Tomo is right, P-47 had a single speed supercharger mounted on the engine fed from the turbo. ALL service fighter R-2800s EXCEPT the Bearcat used two stage superchargers. ALL service bomber R-2800s used single stage superchargers.

The supercharger on the "C" series engine may have been a bit different than on the "B" engines. The single stage supercharger on the "E" engines used in Bearcats was certainly different.

 

[tomo pauk]

The P-47 having, in effect, a two-stage supercharger: auxiliary (= turbo), plus engine stage supercharger
The often overlooked difference between B and C series R-2800 being the extra 100 rpm the C series was capable for, the extra rpm always being a benefit for power, and altitude that power was achieved.
Eg. the A series was managing 100 rpm less than B series (all single stage in this comparison, 2600 rpm vs. 2700), making 150 HP less for take off, and with maybe 100 HP less at 15000 ft.

 

[gjs238]

The R-2800 in F6F and F4U was always featuring the 2-stage blower. The F4U-4 was using the C series R-2800, again 2 stage, that was able to give both more power, and at higher altitude.
The only single stage users of R-2800 were the bombers, eg. B-26, A-26, Lockheed Harpoon (B-34).

Ah, so then perhaps the F6F and F4U could have been suitable for the ETO high-altitude ops?

 

[gjs238]

As widely known, USN fighters (and others) were powered by radial engines. So, is there any proponent here that could make a strong case for the USN adopting the V-12 engines for it's fighters (not only those?), from 1940 until the end of the war? The engines that can take part here are the V-1710s and V-1650s, maybe even the V-3420s, all while respecting the time line of engines production in the USA.

Starting over with a quote from the original post.

If the P-36 was the contemporary of the F4F, and the P-36 was replaced by the V-1710 powered P-40, then doesn't it seem reasonable to consider a V-1710 powered replacement for the F4F?

 

[rinkol]

No, but the USN seemed willing to accept a fixed wing (P40F) if they could get superior performance. The Hurricane II had a considerably better P/W ratio than the F4F-4 with the same wing area and it should have better TO performance than either the P-40 or F4F-4.

Yes, the Secret Years states that the Hurricane IIc had a TO distance of 235 yds at 7400lb versus 320 yds at 7800lb for the Martlet. BWOC, the Fulmar II had a 300 yd TO. (all aircraft with no wind)

At the time, there was still a commonly held attitude that aircraft with liquid cooled engines were generally faster than those with radial engines Also, it was known that the P-40 displayed a significant gain in speed over the P-36 (though this was partly due to the use of flush rivets). So interest in available fighter aircraft with liquid cooled engines would not be surprising. As it turned out, the new generation fighters with 18 cylinder radial engines, specifically the R-2800, demonstrated significant performance increases while maintaining important practical advantages, such as lower maintenance.

Aside from this, it might be noted that a fast climb rate was particularly important for carrier fighters - it was essential to be able to take off and reach the altitude of approaching enemy aircraft in time to prevent them from completing their mission.

 

[tomo pauk]

I'm not sure that fighters with R-2800 were featuring 'lower maintenance'.

Ah, so then perhaps the F6F and F4U could have been suitable for the ETO high-altitude ops?

The F4U-1 series was capable for some 400 mph at 25000 ft. That would be competitive vs. LW opposition, especially vs. Bf-109s of 1943 (= DB-605 restricted) and Fw-190s of 1944 (=heavier A-7s and A-8s). The rate of climb was favoring German fighters, though.
The F6F seems a tad slower, some 10 mph. Again, the LW fighters climb better.
For comparison, the 1943 P-47 does 420 mph at 25000 ft. It can't climb worth a dime, though.