Continental Aircraft Engine Frequently Asked Questions

Manuals & Publications

IO-346 parts manual - where do I get one?

Continental isn't publishing it so we made a copy for you

Right here:

IO-346 Parts Manual

Note: File is a viewer program (.exe) that you click and run. There are no installation files or changes to your registry.

What is the TBO time for my engine

Click on the following link for a copy of Continental Service Information Letter SIL 98-9 Time Between Overhaul Period.

TBO times

 

Although this crack may not look bad --it extends approximately 1/4 around the pressure chamber (cylinder head). In short time the cylinder head will blow off. tip: if you pluck the cylinder fins they will make a ringing sound --except where the crack extends into the base of the fins. These fins make do not ring like the rest.

Another source for tbo information and engine specifications is the following pdf file from Continental
Continental Engine specifications

Specifications for Continental engines

This is a link to a pdf file from Continental

Continental engine specifications

How do I convert a C-75 to a C-85? What about A series Continental aircraft engines

Here it is after many requests. Continental Service Bulletin M47-16 for Converting A and C
series engines. This bulletin is dated 1947 and has not been distributed by Continental in many, many
years.
 

What is the torque setting for ...?

Click on this link to get the latest torque settings in Acrobat format

Continental SB 96-7B

Maintenance Practices

Cold weather operation

Continental has some very useful information for both mechanics and pilots.

The program below is a copy of Continental Service Instruction on the subject:

Service Information Letter 03-1

Program size: 392KB
download time: 1 minute 42 seconds at 56.6 modem
Installation: download program and click on it. This is a simple viewer program

What is the difference between parallel head and angle head

Both Lycoming and Continental engines use a parallel and angle head design on their cylinders.
For example, the early IO-470 engines were of parallel head design and later models used a angle head design. Lycoming 540 engines can be parallel head or angle head. Especially, when ordering rocker cover gaskets we may ask whether you have a "parallel head" or "angle head".

Angle head have the valves entering the combustion chamber at an angle and therefore use two rocker shafts. Parallel head cylinders have the valves entering the combustion chamber parallel to one another and therefore use one rocker shaft.

Here's an example of both:

Continental O-200 parallel head cylinder

Continental O470 angle head engine

For those who have to ask which is better: Angle head - read my Sky Ranch Engineering Manual to find out why - shameless plug!

How do I time the Continental engine

Check out Continental Service Bulletin 94-8 or latest edition

SB94-8

I need a ring set for my 520 engine

Sorry, not enough information. Since Continental has about half a dozen pistons styles that were made for the IO520 (and 470) series engines, we need to know the piston part number you are using. Next, we need to know what cylinder surface you have, steel, chrome, chrome hybrid, etc. since some of the chrome hybrids have their own ring recommendations.

The piston part number is not the casting number you find on the inside of the piston. We can translate the casting number to a piston part number (however, some pistons with identical casting numbers had several different piston ring groove widths!).

The bottom line is that to determine what is the correct part for your engine repair takes an expert and research to do it right. There are many different ring sets for 520 (and 470) engines.

Click on the following link for Continental Magneto to Engine Timing Service Bulletin in Acrobat (pdf) format

Continental service Bulletin MS94-8A

Engine Compression test - what are the limits

Copy of Continental Service Bulletin SB03-3 "Differential Pressure Test and Borescope Inspection Procedures for Cylinders

and just what is a "Differential Pressure Test"?
It used to be called a "compression test" which is an inaccurate description. Then Continental in Service Bulletin M84-15 changed the name to "Cylinder Leakage Test (Compression)". Now it is a "Differential Pressure Test"

How do I preserve my Continental engine?

CONTAINS USEFUL INFORMATION PERTAINING TO THE CONTINENTAL AIRCRAFT ENGINE

SUBJECT: ENGINE PRESERVATION FOR ACTIVE AND STORED AIRCRAFT
PURPOSE: Provide current engine preservation information
COMPLIANCE: During periods as specified by this document
MODELS AFFECTED: All Continental Engine Models
GENERAL
There is no practical procedure that will insure corrosion prevention on installed aircraft engines. Susceptibility to corrosion is influenced by geographical location, season and usage. The owner/operator is responsible to recognize the conditions that are conducive to corrosion and take appropriate precautions.
ENGINE PRESERVATION
Corrosive attack can occur in engines that are flown only occasionally regardless of geographical location. In coastal areas and areas of high humidity, corrosive attack can occur in as little as two days. The best method of reducing the likelihood of corrosive attack is to fly the aircraft at least once every week for a minimum of one hour.
NOTE...
Corrosive attack may reduce engine service life. Of primary concern are cylinders, piston rings, valves, valve guides, camshaft and lifters.
TEMPORARY STORAGE (Aircraft that are not flown for 30 to 90 days)
Preparation for storage.
1. Remove oil sump drain plug and drain oil. Replace drain plug, torque and safety. Remove oil filter. Install new oil filter, torque and safety. Service engine to proper sump capacity with oil conforming to MIL-C-6529 Type II.
2. Perform a ground run-up. Perform a pre-flight inspection and correct any discrepancies. Fly the aircraft for one hour at normal operation temperatures.
WARNING
To prevent possibility of serious bodily injury or death, before moving the propeller accomplish the following:
a. Disconnect all spark plug leads.
b. Verify magneto switches are connected to magnetos, that they are in the "OFF" Position and "P" leads are grounded.
c. Throttle position "CLOSED."
d. Mixture control "IDLE-CUT-OFF."
e. Set brakes and block aircraft wheels. Insure that aircraft tie-downs are installed and verify that the cabin door latch is open.
f. Do not stand within the arc of the propeller blades while turning the propeller.
3. After flight remove all spark plug leads and remove the top spark plugs. Protect the ignition lead ends with AN-4060 Protectors. Using a common garden sprayer or equivalent, spray atomized preservative oil that meets MIL-P -46002, Grade 1, at room temperature through upper spark plug hole of each cylinder with the piston at bottom dead center position. Rotate crankshaft as opposite cylinders are sprayed. Stop crankshaft with none of the pistons at top dead center.
4. Re-spray each cylinder. To thoroughly cover all surfaces of the cylinder interior move the nozzle or spray gun from the top to the bottom of the cylinder.
5. Install top spark plugs but do not install spark plug leads.
6. Seal all engine openings exposed to the atmosphere using suitable plugs and covers. Attach a red "REMOVE BEFORE FLIGHT" streamer at each location.
7. Tag each propeller in a conspicuous place with the following notation on the tag: DO NOT TURN PROPELLER - ENGINE PRESERVED - PRESERVATION DATE .
NOTE...
If the engine is not returned to flyable status on or before the 90-day expiration, it must be preserved in accordance with "Indefinite Storage" procedures in this document.
INDEFINITE STORAGE (Aircraft that are not flown for 90 days)
Preparation for storage:
1. Remove oil sump drain plug and drain oil. Replace drain plug, torque and safety. Remove oil filter Install new oil filter torque and safety. Service engine to proper sump capacity with oil conforming to MIL-C-6529 Type II.
2. Perform a ground run-up. Perform a pre-flight inspection and correct any discrepancies. Fly the aircraft for one hour at normal operation temperatures.
WARNING
To prevent possibility of serious bodily injury or death, before moving the propeller accomplish the following:
a. Disconnect all spark plug leads.
b. Verify magneto switches are connected to magnetos, that they are in the "OFF" Position and "P" leads are grounded.
c. Throttle position "CLOSED."
d. Mixture control "IDLE-CUT-OFF."
e. Set brakes and block aircraft wheels. Insure that aircraft tie-downs are installed and verify that the cabin door latch is open.
f. Do not stand within the arc of the propeller blades while turning the propeller.
3. After flight remove all spark plug leads and remove the spark plugs. Protect the ignition lead ends with AN-4060 Protectors. Install protective plugs P/N 22671 in bottom spark plug holes. Using a common garden sprayer or equivalent, spray atomized preservative oil that meets MIL-P-46002, Grade 1, at room temperature through upper spark plug hole of each cylinder with the piston at bottom dead center position. Rotate crankshaft as opposite cylinders are sprayed. Stop crankshaft with none of the pistons at top dead center.
4. Re-spray each cylinder. To thoroughly cover all surfaces of the cylinder interior move the nozzle or spray gun from the top to the bottom of the cylinder.
5. Install dehydrator plugs MS27215-1 or -2 in each of the upper spark plug holes. Make sure each plug is blue in color when installed.
6. Attach a red "REMOVE BEFORE FLIGHT" streamer to each bag of desiccant. Place a bag of desiccant in the exhaust pipes and seal the openings.
7. Seal all engine openings exposed to the atmosphere using suitable plugs and covers.
8. Tag propeller in a conspicuous place with the following notation on the tag: DO NOT TURN PROPELLER - ENGINE PRESERVED -PRESERVATION DATE .
INDEFINITE STORAGE INSPECTION PROCEDURES
1. Aircraft prepared for indefinite storage must have the cylinder dehydrator plugs visually inspected every 15 days. The plugs must be changed as soon as they indicate other than a dark blue color. If the dehydrator plugs have changed color in one-half or more of the cylinders, all desiccant material on the engine must be replaced.
2. The cylinder bores of all engines prepared for indefinite storage must be re-sprayed with corrosion preventive mixture every 90 days.
RETURNING AN ENGINE TO SERVICE AFTER STORAGE
1. Remove seals and all desiccant bags.
2. Remove cylinder dehydrators and plugs or spark plugs from upper and lower spark plug holes.
3. Remove oil sump drain plug and drain the corrosion preventive mixture. Replace drain plug, torque and safety. Remove oil filter. Install new oil filter torque and safety. Service the engine with oil in accordance with the manufacturer's instructions.
WARNING
To prevent possibility of serious bodily injury or death, before moving the propeller accomplish the following:
a. Disconnect all spark plug leads.
b. Verify magneto switches are connected to magnetos, that they are in the "OFF" Position and "P" leads are grounded.
c. Throttle position "CLOSED."
d. Mixture control "IDLE-CUT-OFF."
e. Set brakes and block aircraft wheels. Insure that aircraft tie-downs are installed and verify that the cabin door latch is open.
f. Do not stand within the arc of the propeller blades while turning the propeller.
4. Rotate propeller by hand several revolutions to remove preservative oil.
5. Service and install spark plugs and ignition leads in accordance with the manufacturer's instructions.
6. Service engine and aircraft in accordance with the manufacturer's instructions.
7. Thoroughly clean the aircraft and engine. Perform visual inspection.
8. Correct any discrepancies.
9. Conduct a normal engine start.
10. Perform operational test in accordance with "Operational Inspection," of the applicable Maintenance Manual.
11. Correct any discrepancies.
12. Perform a test flight in accordance with airframe manufacturer's instructions.
13. Correct any discrepancies prior to returning aircraft to service.
14. Change oil and filter after 25 hours of operation.

How do I install the crankshaft oil seal

After downloading just click on the file. It is a self-contained viewer program

Copyright 2003 by Sacramento Sky Ranch Inc. All rights reserved.  Prices subject to change without notice. Not responsible for typographical or misprint.
Disclaimer: sacskyranch.com contains abundant information relating to aircraft maintenance. The information provided  is not intended to supercede or supplement the F.A.A. approved  maintenance and/or operator’s manuals. Those F.A.A. approved manuals must be utilized when performing maintenance and/or operating aircraft.