Allison V-1710-39/73/81

[greybeard]

Dear Sirs,

after one day search (both in literature I have and on the Internet), I'm totally confused about engines in object, as employed on (respectively) P-40E/K/M. I just collected a sheer chaos of contradictory data.

I would be sincerely grateful if you could put, in the simplest and clean way, for each of them:

Emergency power (if any) at sea level and relevant time interval, RPM and MAP. Rated altitude and related power.
Take off power at sea level and relevant time interval, RPM and MAP. Rated altitude and related power.
Military power at sea level and relevant time interval, RPM and MAP. Rated altitude and related power.
Maximum continuous power at sea level and relevant RPM and MAP. Rated altitude and related power.

Thank you very much!
GB

 

[Micdrow]

Not sure if this will confuse you any more but seen this link yet

P-40 Performance Thread

 

[tomo pauk]

The Peril's P-40 site is a very good asset. The Allison engines' specifications docs are available here (link), scroll down. A caution: if the column 'with ram' is filled, and the column 'without ram' is empty, the altitude figures are for 'without ram' condition.

 

[greybeard]

Thank you gentlemen,

apparently, links you gave provide a lot of data; unfortunately, at a closer look, none of them includes what I'm searching (oddly enough, since I'm not looking for exotic things like, say, the tightening torque od each of the engine bolts, but just power and rated altitude...).

Please, let me explain by an example: let's take the V-1710-73 as powerplant of the P-40K. Document at link provided by Micdrow gives a military of 1150 at 11,800; no takeoff power, no emergency power (if any). Top speed is missing.

historyofwar gives a power output of 1325 (emergency? Military? At takeoff? At altitude?) and a top speed of
370 mph at 20,000.

p40warhawk.com supplies again a 1325 hp for takeoff, and 1150 hp at 11,800 feet. It is unclear if the former is in emergency or both are military. Top speed is missing.

Same figures are produced by the relevant Aicraft Profile (1325 hp for takeoff, and 1150 hp at 11,800 feet). Top speed is presented as 362 mph at 15000 ft.

At this point, I wonder how it could reach 370 mph at 20,000', or even 362 at 15,000, since 3200 feet of rated altitude gained by ram effect seems to me sort of a miracle... Would be helpful knowing MAP of the 1325 hp at takeoff and up to which altitude it could be maintained, or if an higher emergency power was available (GregP mentions 1470 hp at 56" Hg about the V-1710-39 of the P-40E)... But here I again fall in total confusion...

 

[greybeard]

I'm so sorry!

Perusing documents at links you provided, I realized to have missed a lot of things: actually they include all data I was looking for. Definitely, I was still too confused when I gave them first glance, and too stupid to pretend giving an answer at once!

A sincere thanks for your competent and prompt reply.

Cheers,
GB

 

[tomo pauk]

Glad you've found the replies heplful after all, GB.
Are there any details you want to discuss, since I love discussing the hardware?

 

[greybeard]

Are there any details you want to discuss, since I love discussing the hardware?

No, thank you, at the moment no.

Your offer still encourages me to write more on this board; after the fool that I did, I thought nobody wanted to hear more.

 

[MIflyer]

Okay, just for supplementary info here is the summary from the book "Vee's For Victory"

V-1710-39 (V-1710-F3R) 4,694 built, Compression Ratio 6.65:1, weight 1310 lb, supercharger OD 9.50 in, supercharger gear ratio 8.8:1, Carb PD-12K2, 1150 HP at takeoff at 3000 RPM, Max Takeoff MAP 45.5, military rating 1150 HP at 3000 rpm at 11,700 ft at 44.6 in, War Emergency rating 1490 HP at 3000 rpm at 4,300 ft at 56 in with100 octane fuel.

Do you want this kind of data on the other two engines as well?

My apologies, I'm a mechanical engineer!

 

[MiTasol]

Okay, just for supplementary info here is the summary from the book "Vee's For Victory"
My apologies, I'm a mechanical engineer!

Thanks for the book title - another now added to my library. Found dozens at BookFinder.com: Search Results (Matching Titles)

Mi Tasol