Need some engine help...

[Willy]

I'm trying to find out the critical altitude, max Manifold Air Pressure, for the 750-875hp (preferably the 875) Pratt & Whitney, R-1690 Hornet radial engine. I've got the max RPM (2300), just having problems finding the other data.

Figured someone here might have an reference on old engines.

Willy

[Sandydog]

Sorry, I was able to find you this bit of info, but manifold pressures seem to be made of unobtainium.

http://www.oldengine.org/members/diesel/Duxford/usaero11.htm

This article 'surrounds' the R-1690, maybe it'll help.

http://www.geocities.com/CapeCanaveral/Lab/4515/engine2.htm

J

[Ferry_vO]

You might want to try to contact P&W themselves, or perhaps a museum or organisation that uses that type of engines. Perhaps the CAF ?

The 1690 has been used on a lot of different aircraft, there are most likely a few still flying around these days.

:)

[Ralf Roggeveen]

I have access to Jane's All the World's Aircraft from 1929 to the present. The old ones have an aero engine supplement at the back. I believe the Hornet dates from around 1926 and was still in production till the end of the 2nd War, around '46? The 1929 Janes gives us this PERFORMANCE data:

575 h.p. at 1,950 r.p.m., Fuel consumption .55 lb. (.25 kg.) per h.p. hour guaranteed, Oil consumption 0.35 lb. (0.016 kg.) per h.p. hour guaranteed, 2 : 1 Reduction gear drive 550 h.p. at 1,950 r.p.m., Fuel consumption .60 lb. (.27 kg.) per h.p. hour guaranteed.

Don't know if this information is useful, or not, being no engineer, no mention of altitude...does not the original question depend partly upon (a) the aerodynamics of the aircraft in question? & (b) exact year of production of that long-running engine?

Might be able to give more Jane's help if you can tell me the aeroplane it's in. I could certainly scan in relevant data from Jane's & send it by Private Message if that remains Classified to the general public! ;)

[Willy]

I have access to Jane's All the World's Aircraft from 1929 to the present. The old ones have an aero engine supplement at the back. I believe the Hornet dates from around 1926 and was still in production till the end of the 2nd War, around '46? The 1929 Janes gives us this PERFORMANCE data:



Don't know if this information is useful, or not, being no engineer, no mention of altitude...does not the original question depend partly upon (a) the aerodynamics of the aircraft in question? & (b) exact year of production of that long-running engine?

Might be able to give more Jane's help if you can tell me the aeroplane it's in. I could certainly scan in relevant data from Jane's & send it by Private Message if that remains Classified to the general public! ;)


Actually, I'm working on new flight models for Bill Lyons Sikorsky S-43 and the Gee Bee Q.E.D. Both were Hornet powered. After Sandydog posted his immensely helpful info, the only thing I'm really needing are those elusive MAPs. The model Hornets I'm working on are from the 1930s. Just realized that the BMW 132 (Ju 52) was a license built version of the Hornet. Might be a source for somewhat realistic MAP numbers. Now to go find Farmboy's Ju 52 airfile and see what he's got in there..... ;)

Edit: Farmboy has 36 max MAP and 9 min MAP for the 725hp BMW 132. Sounds pretty reasonable to me.

[Gnoopey]

I'm trying to find out the critical altitude, max Manifold Air Pressure, for the 750-875hp (preferably the 875) Pratt & Whitney, R-1690 Hornet radial engine. I've got the max RPM (2300), just having problems finding the other data.

Figured someone here might have an reference on old engines.

Willy

over here Willy ==> http://www.enginehistory.org/P&W/R-1690/Hornet.pdf

[Willy]

Thanks Gnoopey! That has a lot more specifics on the P&W R-1690 Hornets used on the Sikorksy S-43/JRS-1.

Still looking for a source on the MAP range though. I do know that when those numbers are plugged into the aircraft.cfg for the S-43, hang on because it's too darn fast.

[Gnoopey]

Thanks Gnoopey! That has a lot more specifics on the P&W R-1690 Hornets used on the Sikorksy S-43/JRS-1.

Still looking for a source on the MAP range though. I do know that when those numbers are plugged into the aircraft.cfg for the S-43, hang on because it's too darn fast.

have found some more links in my favorites @ home ... hadn't got that one when I did the first post - perhaps even better ... ==> http://www.enginehistory.org/moddesig.htm

EDIT: ... there in Section I - Reciprocating Engine Characteristics - is just another link to a .tif file ==> http://www.enginehistory.org/ModDesig/I2%207.tif

[Willy]

Thanks Gnoopey! Still no Manifold Air Pressures, but a lot of good into regardless.

I'm hoping to do a workbook flight model for the S-43/JRS-1. It set seaplane altitude records, but the FS version runs out of breath about 13000ft short of 29000.