# TCDS E-261: Curtiss-Wright/Marquette Inc.

- Type: Type certificate data sheet
- Status: Current
- Holder: Curtiss-Wright/Marquette Inc.
- Revision: 3
- Revised: December 28, 1983
- Product: Engine
- Certification basis: Part 13
- Data sheet PDF: https://openairdocs.org/files/sha256/7d/29/7d2967b92123defd8d5c26f9ecaa76b03a94290c19106f9123b49548c2411d17
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/5C153F854F88FE6E8525670B006C4883.0001
- Page: https://openairdocs.org/tcds/E-261

## Models (1)

As the data sheet lists them.

- Cyclone 957C7BA1

## What the data sheet says

From the PDF's text layer, line by line; tables lose their columns. The PDF is the record.

```text
Page No. 1 2
Rev. No. 3 3
Reformatted 10/94
DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION
E-261
Revision 3
WRIGHT
Cyclone
957C7BA1
December 28, 1983
TYPE CERTIFICATE DATA SHEET NO. E-261
Engines of models described herein conforming with this specification and approved data on file with the Federal Aviation
Agency meet the minimum standards for use in certificated aircraft in accordance with pertinent aircraft specifications and
applicable portions of the Civil Air Regulations provided they are installed, operated and maintained as prescribed by the
approved manufacturers' manuals and other approved instructions.
Type Certificate Holder Curtiss-Wright/Marquette, Inc.
Fountain Inn, South Carolina
Model     Cyclone 957C7BA1
Type      7RA .5625:1 reduction gearing
Rating (impeller gear ratio) 7.21:1
Maximum continuous, hp, rpm, in. Hg., at:
Critical altitude (ft.) 700-2400-37.0-7300
Sea level 700-2400-39.5-S.L.
Takeoff (Five minutes); hp, rpm, in. Hg. at:
Critical altitude (ft.) 800-2600-42.5-5500
Sea level 800-2600-43.5-S.L.
Fuel (Min. grade aviation gas.) Grade 91/96
Lubricating oils MIL-L-6082, WAS Spec. 5815 or 5818
Bore and stroke, in. 6.125 x 6.312
Displacement, cu. in. 1301
Compression ratio 6.2:1
Weight (dry), lbs. 1065
C.G. location (dry)
Fwd. of mounting pad Centerline, in. 5.7
Above prop. shaft, in. 0.1
Propeller shaft, SAE No. 40
Crankshaft dampers - torsional and lateral 3½ order - front and rear
Carburetion Stromberg PD9F1 carburetor
Ignition, Dual Bosch S7LU-2 magnetos
Timing, °BTC 20
Spark plugs See NOTE 5
Certification basis Type Certificate No. 261
Production basis Production Certificate No. 8
NOTE 1. Maximum permissible temperatures:
Cylinder head 475°F 500°F for takeoff
Cylinder barrel 325°F
Oil inlet 220°F

E-261 2
NOTE 2. Fuel and oil pressure limits:
Min. Max.
Fuel pressure limits 10 psi 21 psi
Oil pressure limits 60 psi 70 psi
NOTE 3. The following accessory drives are provided: Maximum Torque
(in. lb.) Maximum Overhang
Rotation* Speed** Continuous Static Moment (in. lbs.)
Starter C 1:0 25800 300
Generator and Accessory gear C 3:31 500.0 2200 350
Fuel Pump CC 1.0 25.0 450 
Vacuum Pump CC 1.5 100.0 800 25
Hydraulic Pump CC 1.5 250.0 1650 50
Propeller Governor C 1.0 125.0 825 
  *"C"  =  Clockwise viewing pad. "CC"  =  Counter clockwise.
**Speed  =  X crankshaft.
NOTE 4. In addition to complying with Part 13 of the Civil Air Regulations dated August 1, 1949, this engine  also complies
with engine airworthiness requirements contained in Annex 8, dated April 1949 of the International Civil Aviation
Organization.
NOTE 5. The following spark plugs are approved on these engines:
AC 172, 181, 272, 281
BG RB19R-2, RB27R-1
Champion R119, R819, REA87N, RHA87N, RHB87N
.....END.....
```

## ADs

None name its models.

## STCs approved under this data sheet (1)

- [STC SE01966WI](https://openairdocs.org/stc/SE01966WI): Use of GAMI G100UL High Octane Unleaded Avgas in spark ignition piston aircraft engines. General Aviation Modifications Inc.

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