I Need Help With Historical Data On Ash-82Fn

[6./ZG26_Klaus_Mann]

So, I got into a somewhat heated argument with some guys and I need help.

The Question is about the engine type employed by the La-5FN in its early and late version.

According to the Wiki the ASh-82FN existed in two major versions, the FN and FNU with a changed supercharger.

The FN according to the WIki delivered 1650hp, while the FNU delivered 1850hp.

I also remember reading about the original mid 1943 FN being switched to the FNU Version in mid 1944 with the introduciton of the La-7, and that the FNU was then also used for the La-5FN.

I am now looking for more detailed sources to either prove my point or correct myself.

PLEASE HELP!

[YSoMadTovarisch]

Wiki is wrong, with Forszah the FN's already able to deliver 1850hp.

[sallee]

I have Russian Piston Aero Engines by Vladimir Kotelnikov. I'll have a look...

[6./ZG26_Klaus_Mann]

This is what I'm referring to.

 

• Power output:
• M-82-111 with carburettors:
• 1,570 hp (1,170 kW) at 2,400 RPM for take-off (Dry), boost rated at 1.55 Atm (46.3")
• 1,540 hp (1,148 kW) at 2,400 RPM at 6,656 ft (2,050 m)
• 1,330 hp (992 kW) at 2,400 RPM at 17,716 ft (5,400 m), boost rated at 1.29 Atm (38.6")
• 820 hp (612 kW) at 2,400 RPM at 27,887 ft (8,500 m)
• M-82FN with direct fuel injection:
• 1,650 hp (1,230 kW) at 2,400 RPM for take-off (Dry), boost rated at 1.55 Atm (46.3")
• 1,430 hp (1,067 kW) at 2,400 RPM at 16,404 ft (5,000 m)
• 800 hp (597 kW) at 2,400 RPM at 32,808 ft (10,000 m)
• M-82FNU:
• 1,850 hp (1,380 kW) at 2,500 RPM for take-off (Dry), boost rated at 1.60 Atm (47.88")
• 1,650 hp (1,230 kW) at 2,400 RPM at 5,413 ft (1,650 m), boost rated at 1.36 Atm (40.7")
• 1,450 hp (1,082 kW) at 2,400 RPM at 15,156 ft (4,650 m), boost rated at 1.36 Atm (40.7")
• 810 hp (604 kW) at 2,400 RPM at 34,448 ft (10,500 m)

[sallee]

Can't find any reference to a separate FNU variant, although Putnam's "Russian Aircraft since 1940" refers to the FN initially developing 1,700 hp for take off, but soon being rated at 1,850 hp for take off.

 

The later variants of the ASh-82 are given by Kotelnikov as the NV (with turbo superchargers) which was flight tested in 1944 but not put into production, and then a number of post-war variants.

[6./ZG26_Klaus_Mann]

Can you Post Pages maybe?

[JtD]

First time ever I hear about "FNU". I've got several manuals of the La-5FN and Ash82-FN engine spanning 1943-1946 and none of them mention less than 1850hp@2500rpm@1180-1200mm boost as WEP and all refer to the engine as "FN", if they name it.

 

No manual mentions an FN and FNU version of the engine. I know of model 112,212 and 312 FN engines which had different prop gear ratios.

 

Does anyone have any aircraft manual (Su-2, Pe-8, Tu-2, La-5, La-7) where the aircraft is equipped with the FN engine and is not given with 2500 take off rpm?

 

Attached a picture from a post war FN manual - no mention of FNU, but 1850hp at take off.

Edited March 11, 2015 by JtD

[sallee]

Best I can do.

 

[JtD]

ФНВ - FNV, not FNU. Thanks for that tip.

 

Still not used in the manuals I know, but at least exists in literature - but only as a re-designation, not as a technical change.

Edited March 11, 2015 by JtD

[6./ZG26_Klaus_Mann]

As far as I understand the change was boost pressure and minor changes to the supercharger. It basically was a retuned version of the Original ASh-82FN. The changes were not significant enough to carry over into the outside world in means of name change. I would love some more detailed Descriptions of the engines and production figures.