# STC SE3877NM

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: Kai V. Nielsen, United States
- Description: Modification of a Lycoming O-235-L2C engine to increase the horsepower rating from 115 HP @ 2700 RPM to a continuous 125 HP @ 2800 RPM
- Applied: October 1, 1986
- Status date: January 8, 2008
- Product: Engine
- Certification basis: Part 13, Part 21
- Data sheets: [TCDS E-223](https://openairdocs.org/tcds/E-223)
- Certificate PDF: https://openairdocs.org/files/sha256/5e/ec/5eec60ee6312fac4bf13c40734ddeb3c79bb0eef6f3291c4439fa9c53cb5d1fb
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/2FA28653B7E116A0862573DA00567559.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SE3877NM

## ADs that name it (0)

None.

## Approved models (1)

- Textron Lycoming AVCO Corporation O-235-L2C ([TCDS E-223](https://openairdocs.org/tcds/E-223))

## What the certificate says

Read from the PDF's text layer, without the form's printed wording; the layout is lost and the order can differ. The PDF is the record.

Number SE3877NM

This certificate, issued to Kai V. Nielsen 19212 59 th Dr. N.E. #10 Arlington, WA 98223

Part 13 of the Civil Air Regulations, dated June 15, 1956 as amended by 13-1, 13-2, and13-3.

Original Product⎯Type Certificate Number: E-223-16 Make: Lycoming Model: O-235-L2C

Description of the Type Design Change: Modification of a Lycoming O-235-L2C engine to increase the horsepower rating from 115 HP @ 2700 RPM to a continuous 125 HP @ 2800 RPM in accordance with Maynard C. Crosby Installation Instructions MCC 1001.

NOTE: The modified engine shall be designated as O-235-L2C(M).

Limitations and Conditions: Approval of this change in type design applies basically to the above model engine only. This approval should not be extended to other engines of this model on which other previously approved modifications are incorporated unless it is determined that the interrelationship between this change and any other previously approved modifications, including changes in type design, will introduce no adverse effect upon the airworthiness of that engine. A copy of this certificate and continuation sheet shall be maintained as part of the permanent records for the modified engine.

If the holder agrees to permit another person to use this certificate to alter the product, the holder shall give the other person written evidence of that permission.

Date of application: October 1, 1986 Date reissued: January 8, 2008 Date of issuance: July 24, 1987 Date amended: January 8, 2008

(Signature) Acting Manager, Seattle Aircraft Certification Office (Title)

Department of Transportation_Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number SE3877NM

Kai V. Nielsen Reissued: January 8, 2008 Amended: January 8, 2008 Limitations and Conditions (continued):

The conditions and limitations of Type Certificate Data Sheet E-223-16 apply except where superseded by the following:

This Supplemental Type Certificate Data Sheet, which is part of STC SE3877NM, prescribes the conditions and limitations under which the product for which the STC was issued meets the airworthiness requirements of the Civil Air Regulations:

SUPPLEMENTAL TYPE CERTIFICATE HOLDER: Kai V. Nielsen

Engine: Lycoming O-235-L2C(Modified)

Fuel: 100/130 minimum grade aviation gasoline

Engine Limits: For all operations, 2800 RPM (125 HP)

Compression Ration: 9.7:1

Sparkplugs: Auburn SR-87 or Equivalent (see Lycoming engine manual for F or J series Engines)

Placards: Placards and Operating Limitations on Type Certificate Data Sheet E-223-16 apply except as noted herein:

a. Original Engine Data Plate:

Add a “suffix” (M) and the STC number to the model designation As follows:

MODEL: O-235-L2C(M) STC SE3877NM

b. Supplemental Engine Data Plate:

Install a Supplemental Data Plate adjacent to the original Data Plate to read as follows:

**AVCO LYCOMING ENGINE**

**SUPPLEMENTAL DATA PLATE STC SE3877NM**

TAKEOFF (5 MIN) 125 HP @ 2800 RPM NORMAL RATE 125 MP @2800 RPM

SPARK ADVANCE – 25 º BTC

- END -

FAA Form 8110-2- 1 (10-69) PAGE 3 OF 3PAGES

## Every issue (1)

- January 8, 2008: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/5e/ec/5eec60ee6312fac4bf13c40734ddeb3c79bb0eef6f3291c4439fa9c53cb5d1fb)

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