# TCDS TC 108: Textron Lycoming AVCO Corporation

- Type: Type certificate data sheet
- Status: Current
- Holder: Textron Lycoming AVCO Corporation
- Revision: 0
- Product: Engine
- Registered aircraft: 2, by the registry models matched to it (OpenAirDocs)
- Data sheet PDF: https://openairdocs.org/files/sha256/45/8f/458f0d862debd302d56551f83735314ac822b95777c2818aef0d95003b3401e8
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/CC71D1B124B456D08525670E004E3511.0001
- Page: https://openairdocs.org/tcds/TC%20108

## Models (2)

As the data sheet lists them.

- R-680-4
- R-680-B4 Series

## What the data sheet says

This is OCR from the scanned FAA data sheet. OCR can misread letters and numbers.

```text
MODELS: Avco Lycoming R-680-B4 series, R-680-4 and Military R-680-5, -7, -8, -11, -17
I.S. NUMBER: I.C. 108
Kodel - Lyccming  R-680-4 and B4  K-680-846
Jype  ORA
Fating:
kaximum continuous,
np. xpm, at 5-1.
press.  alt.  225-2100-5-1.
Jake-oti, ho, rEm,
at full throttle  225-2100
Fuel (rinimum octane
aviation gasoline)  65
bore and stroke, in.  4.625 × 4.5
Disflacement, cu. in.  680-4
Compression ratio  5.5:1
Leight (dry),  ibe.  471  495
Fropeller shaft,
SAE NO.
Carturetion  Stromkerg NA-RIA carburetor  Stromberg NA-R7B carburetor
with 2.0625 in. venturi  with 2.0625 in. venturi
ignition, dual  Scintilla SC-A or SC-AZ magneto  Scintilla DF or DFN magneto
Ignition  tiring,
deg- BIC  Front 30, Rear 30  Front 34, Fear 30
Certification basis  Type Certificate No. 108 (See NOTE 4)
NCIES  1. 2, 4  1.3.4
NOTE 1.  Maximum permissitle cylinder head, tarrel, and oil inlet temperatures, 525 degrees F., 300 degrees F..
and 200 degrees F.. respectively.
R-680-84 engines were formerly designated R-680-4.  Serial Nos. 2-751 and 2-752 engines of these
mcdels are eligible at 215 hp at 2000 rpm for all operations.  The R-680-4 or k-680-B4 may be corverted
to the R-680-B6 which makes it eligitle for use with a controllable pitch propeller.
NOTE 3. Military model R-680-5 is identical to model R-680-B4B.  Models K-689-84C, R-680-B4D and R-680-84L are
similar to model R-680-B48, the differences being noted below.  The corresponding military modeis are indicate:
in farenthesis.
Mcdel  Difference
F-680-B4C (R-680-7)  Includes automatic valve gear lubrication.
R-680-84D (R-680-8, -11)  490 lbs. (dry) weight includes automatic valve gear lubrication
R-680-B4E (R-680-17)  a it. tape, aceight inciudes automatic valve gear lubrication,
AN type accessory drive, a redesigned crankshaft and steel link
the pertinent die model designation and eNo.  the pertinent  certificated aircraft, its rame-plate should te revised to include
NOTE #_  Approval expired 11/2/50.  engines of  these models manufactured after the dates showr. talow or with
above those  indicated, are eligible for use in certification aircraft:
Model  Serial No.  Date
R-680-4 and
R-680-24 and
R-680-B42  8-1619  3/18/39
R-680-E4C  2552  7/15/41
R-680-B4C  3935  12/31/41
R-680-B4E  I015483  3/30/44
```

## ADs (5, in force first)

- [AD 2012-03-07](https://openairdocs.org/ad/2012-03-07): Carburetor · Lycoming Engines GO-435, GO-435-C2 (O-435-17), GO-435-C2A and 389 more. Effective Mar 27, 2012
- [AD 2004-10-14](https://openairdocs.org/ad/2004-10-14): Crankshaft gear · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 642 more. Effective Jun 25, 2004
- [AD 95-26-02](https://openairdocs.org/ad/95-26-02): Aviation Gasoline · Lycoming Engines IO-320-B1A, IO-320-B1B, IO-320-B1C and 182 more. Effective Jan 24, 1996
- [AD 90-04-06 R1](https://openairdocs.org/ad/90-04-06-R1): Propeller Governor External Oil Line · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 427 more. Effective May 28, 1991
- [AD 66-06-03](https://openairdocs.org/ad/66-06-03): Connecting Rod Assemblies · Lycoming Engines GO-435-C2 (O-435-17), GO-435-C2A, GO-435-C2A2 and 317 more. Effective Jan 16, 1969

## Registered aircraft by registry model (OpenAirDocs)

- [Lycoming R-680-B4](https://openairdocs.org/engine/lycoming-r-680-b4): 2 aircraft (registry code 42370)
- [Lycoming R-680-4](https://openairdocs.org/engine/lycoming-r-680-4): 0 aircraft (registry code 42369)

## STCs approved under this data sheet (1)

- [STC SE04651CH](https://openairdocs.org/stc/SE04651CH): To allow use of l00R grade aviation fuel meeting Swift Fuel, LLC specification SPEC-l00R-22. Swift Fuels LLC

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