Item 1110

DESIGN: Engine - Reciprocating - Lycoming - General Information

Note:

Turbine for the Future?:

Consider; Innodyn http://www.innodyn.com/aviation/products.html

Concerns:

The primary drive and prop drive will put radial loading on the engine's crankshaft and block. However, the Robinson R-22 puts a radial load on its O-320 and O-360 engines

Craft Using Lycoming:

Robinson R-22:

From Web page on Governor for Safari:

 

Tacho:

Engine RPM:

Rotor RPM:

Description:

 

104%

2652

530

Top of the green.

 

100%

2550

510

Middle of the green.

 

97%

2473

495

Low RPM horn.

 

80%

2040

408

Governor's switch off.

All R-22s except for Beta II. I believe. Tabular information is from Lycoming data.

 

Model:

HP:

Take-Off RPM:

Fuel:

C.R.

Description:

 

O-320-A2B

150

2700

80

7.0:1

 

 

O-320-A2C

150

2700

80

7.0:1

 

 

O-320-B2C

160

2700

100/100LL

8.50:1

Same as -B2B except for Retard Breaker Magnetos.

 

O-320-B2B

160

2700

100/100LL

8.50:1

Same as -B2A except for straight riser in oil stump and -32 carburetor.

 

O-320-B2A

160

2700

100/100LL

8.50:1

Same as -B1A fixed pitch propeller.

 

O-320-B1A

160

2700

100/100LL

8.50:1

Same as -A1A but high compression ratio.

Notes: The O-320 can make 150 hp at takeoff rpm of 2700 for 5-min, but maximum continuous power is 124 hp; 130hp 5 min limit.

R-22 Beta II. I believe. Tabular information is from Lycoming data.

 

Model:

HP:

Take-Off RPM:

Fuel:

C.R.

Description:

 

O-360-J2A

145

2700/2400

100/100LL

8.50:1

Similar to O-360-C2D except has O-320-B2C prop. flange bushing, lightweight cylinders and low power setting(1).

 

O-360-C2D

180

2700

100/100LL

8.50:1

Same as -C2B except for Retard Breaker Magnetos.

 

O-360-C2B

180

2700

100/100LL

8.50:1

Same as -C1A but fixed pitch prop. and horizontal pressure carburetor and has helicopter rating.

 

O-360-C1A

180

2700

100/100LL

8.50:1

Same as -A1A but conical rubber mounts.

 

O-360-A1A

180

2700

100/100LL

8.50:1

Dynafocal mounts.

(1) Lower power setting = 145 / 180 = 82.2% @ 2400 RPM

Robinson data says that the O-360-J2A is derated to 131 horsepower at 2652 rpm.

Lycoming data say that the O-360s can produce between 180 to 210 hp.

Robinson says that the O-360-J2A t consumes 7 to 10 gallons per hour.

My comments only: Assuming that the O-360 is rated at 180 hp, then the 131 hp represent a reduction to 131 / 180 = 72.8%

This results in 1370 / 131 = 10.45 lbs/hp.

____________________________________

320 cu-in = 5.24386 liters

BMEP = ( HP * 13000 ) / ( L * RPM )

BMEP = (131 * 13000) / (5.24386 * 2652) = 122.45 ( to equate with 2-stroke divide by 2 = 61.23)

1370 lbs / 124 hp. is 11 lb per hp.

____________________________________

From Al Hammer on Rotary Wing Forum:

The R22 engine is de-rated from 160 HP to 124 Hp (75% max rated power) for Max continuous use on a standard day.

The R22 Max takeoff power of 131 HP is about 80% MRP. (Monitor the cylinder head temp gauge on take off at low DAs)

Cicare:

The O-320-A1A was used in the Cicare CH-2 (1964)

The O-320-A2C was used in the Cicare CH-5 AG (1998)

Safari:

"The Safari helicopter uses the Lycoming O-320-B2B, (160-hp.) aircraft engine. Canadian Home Rotors sells only new certified engines from Lycoming. A complete engine package includes a lightweight starter, alternator and Stainless Steel exhaust system. "

"There is no problem operating the Lycoming engine in the vertical position. Small tubes are brazed or welded to the original valve covers to allow the oil to flow directly to the external sump. The Engine Conversion Kit includes the required materials and hoses and fittings for the external oil sump. The crankcase engine oil is drained from the accessory housing to the external sump. The original engine oil sump is removed which incorporates the intake manifold. An aluminum plate from the kit is installed to replace the original sump and a separate intake manifold is bolted in front of the plate. This style of system is commonly known as a dry sump used by high performance aircraft and racing cars. "

The O-320 is used on the Safari. It has a gross weight of 1,500 pounds and a maximum speed of 100 mph.

Comment on a web page: "I purchased a silver kit so I could chose the Lycoming O-360 engine (Robinson R22 Beta II engine) with Slick/Unison LASAR ignition system over the O-320 supplied by Canadian Home Rotors. This setup will provide me 160 HP all the way up to 4600 ft density altitude with only 9 lbs of weight penalty. It has much better starting qualities with the LASAR system, improved engine temperatures, and more power and fuel economy."

Comparison of Lycoming 4-cylinder Engines:

Model:

H.P.

Width:

Height:

Length:

Weight:

O-235 (1)

100 - 116

32.0"

22.4"

29.6"

218 lb.

O-320

140 - 160

32.2"

22.9" - 19.2"

29.6" - 33.6"

244 - 259 lb.

AEIO-320

150 - 160

32.24"

23.18"

29.05" - 30.70"

258 - 271 lb.

IO-360

180 - 210

33.4" - 36.3"

24.6" - 19.35"

33.4" - 36.3"

265 - 348 lb.

All three engines are dimensionally very close and use the same dynafocal mount dimensions. Their difference is weight and power; in addition, the AEIO-320 is aerobatic and fuel-injected.

(1) Bob Schneider (Progressive Air Services) suggested not using the O-235. It is an older engine and the parts are more expensive than those for the O-320.

The manifold pressure is the means of limiting the power extracted from the engine. ???

The difference between the AIO-320 and the AEIO-320 is that the the AIO was built by Lycoming and is no longer produced. The AEIO is produced by Avat?? and is the one to consider.

The O-320 engines with the same RPM, compression ratio and fuel as the R-22 Beta II O-360 engines above has 160 hp. 160 hp * Robinson's derating of 72.8% = 116.4 hp. This is 1150 / 116.4 = 9.88 lbs/hp

Comparison of Lycoming 6-cylinder Engines:

Fun consideration re attempt to set speed record. Probably using twin pusher propellers. The weight is not a problem.

Model:

H.P.

Width:

Height:

Length:

Weight:

O-540

235 - 350

34" - 35"

24" - 20"

37" - 40"

370 - 550 lb.

Increase over O-320

150 +/-

2" +/-

0" +/-

8" +/-

150 lb. +/-

Weights:

Here are some weights for Lycoming engines. Note that it's a little confusing because Lycoming doesn't agree with itself regarding engine dry weights.

I have two sources for engine weights:

1. The _Piston Engine Selection Guide_

2. Individual Operator's Manuals

The latter is much more specific (breaks down weights by engine suffix, not just the basic engine group) and seems to show the engines as slightly heavier than the _Piston Engine Selection Guide_ does. I don't have all the Operator's Manuals (one big hole is that I don't have Operator's manuals for the 540 series (just the 541) nor the 720 series or the

235 series. For those I just have the numbers from the _Piston Engine Selection Guide_).

One POSSIBLE explanation for the weight discrepancy may be improvements in component weights (such as magnetos and alternators). My _Piston Engine Selection Guide_ is a bit more "modern" than my operating manuals.

 

Definitions:

Dry Weight:

The weight of the basic engine plus the weight of the carburetor or fuel injection system, magnetos, spark plugs, ignition harness, baffles, tach and starter/generator drives, generator or alternator + mounting brackets. Dry Weight for turbocharged models includes all of the above PLUS the weight of the turbocharger, turbocharger mount, exhaust manifolds, controls, and oil lines.

Basic Weight:

The weight of the engine alone with no accessories.

The following table is primarily sorted by engine cubic inch displacement and econdarily sorted by horsepower.

Blank entries indicate that I don't have the data.

All weights in pounds.

 

Engine

Dry Weight

Dry Weight

 

Model

(Engine guide)

(Operator's Manual)

 

O-235 (108-125HP)

215

 

 

O-320-A,E (150HP)

244

270

 

AEIO-320-E (150HP)

258

 

 

O-320-H (160HP)

283

 

 

O-320-B,D (160HP)

255

280

 

IO-320-B,C (160HP)

259

290

Notes on the table: Engine Designations are: XX-YYY-ZZ

Where:

 

XX

Engine Configuration

 

O

Opposed (all engines listed)

 

I

Fuel Injected (if omitted implies carb)

 

T

Turbocharged

 

G

Geared (see TIGO-541-E)

 

AE

Full aerobatic (inverted fuel & oil)

 

YYY

Engine Displacement in cubic inches

 

235,320 & 360

engines are all four cylinder

 

ZZ

Specific engine application

Engine Mounts:

The preferred anti-vibration mount for the Lycoming is the Dynafocal, but on helicopter installations, the conical mount is used. This is because the relative motion between the engine and the drive train must be limited. Perhaps the mount between the drive frame and the fuselage can be the Dynafocal.

Engine Selection:

The Falco Construction Note 61003-1 discusses Lycoming engine select. For 'constant-speed-propeller' and conical mounts, the models are 150 hp 0-320-A3B and the 160 hp O-320-B3B. The 150 hp engine can be converted to the 160 hp engine by changing the pistons.

Pusher Configuration:

The ever popular O-320 Lycoming is also suitable for use in pushers without any change. [Source ~ FF p.30]

Direction of Rotation:

The direction of rotation of the crankshaft. viewed from prop end (standing at the back of the craft and looking forward), is CCW.

Installation:

Consider entering the engine into the fuselage from underneath. This will allow the fuselage structure that supports the booms to be a strong one-piece item. Moving it up and forward at insertion should also miss the support structure.

Excessive Load on Crankshaft:

If the pulley and the propeller result in too great a load on the engine's crankshaft, then consider mounting the propeller to the fuselage and locating a flexible coupling between the engine and the propeller.

Magnetos:

Model O-320-B3B, O-320-B1A, O-320-A1A have Bendix S4LN-20 and S4LN-21 Magnetos.

Model O-320-B3C has Retard Breaker Magnetos.

http://www.lycoming.textron.com/support/publications/maintenancePublications/serviceInstructions/SI1506.pdf

http://www.unisonindustries.com/pdf/news_stories/southernaviator_slickstart1111.PDF

http://www.generalaviationnews.com/editorial/articledetail.lasso?-token.key=6245&-token.src=press&-nothing

https://www.unisonindustries.com/products/ignition.html

From Lycoming Textron:

August 21, 2002

Dear Mr. Jackson:

Thank you for your recent E mail inquiring about the use of an O-235 series engine in a helicopter installation.

The O series engines (O, IO, TIO) are normal category engines certified for use in fixed wing applications, while our H series (HO, HIO) are engines specifically for helicopter installations. There is a difference if the certification process between a fixed wing engine, O-xxx and an HO-XXX. The HO engine incorporates a higher overspeed provision in the testing.

While some manufacturer's, such as Robinson Helicopter, utilizes normal category fixed wing engines in their helicopters, however they also derate the engines both in manifold pressure and speed to meet FAA requirements.

This would be the area you would need to investigate should you decide to pursue the installation of a normal O-235 series engine for your helicopter application.

I hope this information proves helpful. If we may be of further assistance, please feel free to contact us.


Regards,

Raymond A. Crist
Distributor Sales Manager
( (570) 327-7075 phone
2 (570) 327-7066 fax
* rcrist@lycoming.textron.com

October 13, 2004

Dear Mr. Jackson,

We have reviewed your e-mail of October 5 and the layouts on your website relating to your proposed installation of an O-320 in the UniCopter. We offer the following responses to your questions:

1) The maximum nose down attitude for continuous operation of the O-320 and O-360 engines is not documented. The potential engine issues with respect to continuous operation at eighteen degrees nose down would be the capability of the engine oil system and the ability of the float type carburetor to adequately meter fuel. We are aware of one installation where
the aircraft manufacturer modified the engine to convert the oil system to a dry sump configuration to allow engine operation over the range of 90 degrees nose up to 90 degrees nose down. A quick analysis of the oil systems on the O-320 and O-360 engines indicates they are probably not capable of continuous operation at nose down attitudes greater that 20 degrees. Therefore it appears your proposal to install these engines at 18 degrees nose down is probably not feasible unless you modify the engine oil system. The potential issues with operation of the carburetor with the engine 18 degrees nose down can be eliminated by use of a fuel injection system that is known to function at these attitudes.

2) Based on the use of belt drives on several helicopter applications, we would not expect the radial belt loads to adversely effect crankshaft bearings. However, depending on the design of the propeller and the length of the extension you plan to add between the rotor drive sheave and the propeller there could be issues with crankshaft flange bending stresses. In addition, either detailed analysis or engine testing would be required to assure the drive system you are proposing would not result in excessive torsional vibration stresses in the crankshaft and other rotating engine components.

3) We do not think the differences in crankshaft flange stresses would be significantly different between 3/8 or 7/16 inch diameter attachment bolts. Therefore, we suggest that you select whichever you feel is appropriate based on the loads on the bolts.

We appreciate your interest in Lycoming engines. Please contact us when we can assist you further.

Best regards,

Dan Fletcher

Applications Engineer

One bolt-in without modification alternative to the Lycoming is Superior's XP-360. This engine is essentially an (I)O-360 but from a different manufacturer with a different pricing scheme (ie. cheaper) and is available either pre-built or as a box of parts kit that needs assembling (SL-360). Obviously there are cheaper used Lycomings available, but if you're looking at buying a rebuilt engine, the incremental cost to a new XP-360 isn't that great. I've got an XP-360 that I'm about to convert and I'm aware of at least one other builder who has used one.

The http://www.superior-air-parts.com/ site has some info, but their listed prices seem a little out of line with what they'll actually quote. The http://www.mattituck.com/ and http://www.aerosportpower.com sites also have some good info on these engines. Remember that if you go this route, there are several valuable items (ie. enhanced sump, fuel pump, oil return lines, etc.) that will not be required after the dry sump conversion and can be sold as new parts on eBay or through some other means. Although it's not listed on their website, the actual model of XP-360 that is required for the Safari is an O360A3B2 (fixed pitch, conical mount). Lasar mags are also offered as an option.

Outside Web Pages:

Lycoming Home Page

Cut-away of a four cylinder power plant

http://www.zenithair.com/zodiac/xl/lycoming.html

http://www.murphyair.com/Product%20Info/Engines/o-235.htm

Information on the differences etc. between Lycoming engines - Falco Construction Note 61003-1 ~ Have hard copy.

Engine Installation - Falco Construction Note 61003-4 ~ Have hard copy

 Don George Aircraft Engines

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Last Revised: November 21, 2005