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Saburo_0
12-12-2008, 10:49 AM
I'm curious why the P-39D2 has more horsepower and is faster (per Hardball's a/c viewer) than the later model p-39N?

I think the D-2 has 1350hp and the N with a later model allison has only 1200hp. Seems kind of odd to me. is the D-2 version in IL2 a limited run or something?

Daiichidoku
12-12-2008, 11:52 AM
p 39 D1/D2
http://home.att.net/~jbaugher1/p39_6.html (http://home.att.net/%7Ejbaugher1/p39_6.html)

Further P-39D versions were ordered specifically for delivery under Lend-Lease. They were produced in two batches--P-39D-1-BE and P-39D-2-BE.

150 P-39D-1-BEs were ordered on June 11, 1941 under contract AC 32. 185 more were ordered on September 17, 1941 under Contract AC 156. An additional P-39D-1 was provided under a separate contract.

The P-39D-1-BE (Bell Model 14A) was powered by an Allison V-1710-35 engine. Like the P-400, the P-39D-1 was armed with a 20-mm M1 cannon rather than the 37 mm Oldsmobile cannon, but the four 0.303-inch wing guns of the P-400 were replaced by 0.30-in guns. The two fuselage-mounted 0.50-inch machine guns were retained. A small dorsal fillet gave the tail a new shape, which became standard on all later P-39s and was retrofitted to most earlier P-39Ds. A total of 336 P-39D-1s were built.

The remaining 158 machines on the Lend-Lease order were produced as P-39D-2-BE (Model 14A-1). These were assembled under contract AC 156 placed on June 1, 1941. The P-39D-2 introduced the uprated 1325 hp V-1710-63 (E6) engine and had a 2:1 reduction gear. It brought back the 37-mm nose cannon. It was otherwise identical to the P-39D-1. The P-39D-2-BE could carry the 145 US gallon drop tank underneath the fuselage.

Most of these planes were originally intended for the United Kingdom. However, the Royal Air Force had rejected the Airacobra as a combat type, and most of these planes were delivered to the Soviet Union instead.

Not all of the P-39D-1 and D-2 aircraft were delivered to the Soviet Union. Several dozen were taken on charge by USAAC squadrons and were flown in combat. Some of these P-39D-1s (along with the P-400) were flown by the 347th Fighter Group at Guadalcanal in August of 1942. Some flew with the 31st Fighter Group in North Africa in 1943.


p 39N
http://home.att.net/~jbaugher1/p39_14.html (http://home.att.net/%7Ejbaugher1/p39_14.html)

Saburo_0
12-12-2008, 01:35 PM
Interesting stuff, Thanks!
I guess I'm just confused why they went from the 1325 Hp V-1710-63 engine to the 1200 Hp V-1710-85 engine?
Perhaps the -63 was less reliable?

No answers but some interesting info:
http://en.wikipedia.org/wiki/Allison_V-1710

M_Gunz
12-12-2008, 03:29 PM
Some things we learned back when Oleg posted here were about the Russian end of the P-39 development program.
From D to N the Russians and Bell worked closely together, the structure was made stronger and armor became less IIRC.
Somewhere in the N to Q series they moved to linked controls which did not please all the pilots.
Which engine(s) were suitable for Russian climates may figure into it but I don't remember that being covered.
The P-39 Wiki does not cover Russian contributions of which there were many -- check how many N and Q models were made,
those are the ones most changed by Russian cooperation with Bell to get what Russia wanted in P-39's.

Kwiatos
12-12-2008, 03:31 PM
Originally posted by Saburo_0:
I'm curious why the P-39D2 has more horsepower and is faster (per Hardball's a/c viewer) than the later model p-39N?

I think the D-2 has 1350hp and the N with a later model allison has only 1200hp. Seems kind of odd to me. is the D-2 version in IL2 a limited run or something?

Yes P-39 D-2 had more horsepower engine Alison V-1710-63 with 1325 HP Take off power and 1590 HP War Emergency Power but IRL 1590 HP could be used only from 0-760m alt.
Unfortunalety these is not correct moddeled in IL2 and P-39 D-2 in game have too much power at all hights so is too good in speed and climb at all heights.
P-39 N-1 had V-1710-85 with War Emergency 1420 HP up to 3km and generally had lower power then D-2 only from at the deck to 760m. N-1 had more power at higher alts so should have and IRL had better performance then D-2. In IL2 Oleg dont check it detalied and his D-2 is better at all heihgts then N-1 which is not correct.

Saburo_0
12-12-2008, 03:51 PM
Kwiatos,

Wow that's really interesting, thanks for all of that information. i thought teh D-2 was awfully hot for an early war fighter!

TgD Thunderbolt56
12-13-2008, 06:16 PM
Ruh roh...the cat's out of the bag!

Don't forget to take that M4 loadout option too... http://forums.ubi.com/images/smilies/10.gif

Saburo_0
12-14-2008, 03:04 AM
LOL. M4 http://forums.ubi.com/images/smilies/59.gif