T

Turbofan

Active Member
I have a tagless IO320 lycoming that I'm trying to ID. Logs make no mention. Any help appreciated.
INJECTED, dynafocal, fixed pitch, advertised as 160hp, vacuum pump, mech fuel pump......all I can think of...is this enough info? Can this even be identified?
Has one slick 4371

Thanks
Tom
Rv 4 project

I've removed cylinders for inspection, I could possibly get a cam number

Would case casting numbers help?
 
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Engine

Where is the fuel injection mounted? Front? Bottom? Rear? The dash number from the top of the crankcase, near the rear, at the top, will help narrow it down. Two or three digit number/letter. You can call Lycoming with the entire number from the top of the case. A lot of the IO engines on US aircraft were Twin Commanche and Citabria.
None of this is definitive if someone changed the crankcase.
 
Many of the IO-320's as used on the Twin Comanche (and a few others) are Dynafocal Type 2, and require either a special mount (18* instead of 30* on Type 1) or modifications of the crankcase.
 
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Engine

The Twin Commanche engine in original configuration can be identified by the injector mounted on the rear of the sump at an angle.
I think most if not all Citabria engines are conical mount.
Is the engine configured for a constant speed prop?
 
Injection bottom mounted, where carb usually is.
Only numbers on case halves are located on top rear, just in front of access case....16780Q3 on both halves....72081 and 72082 are numbers between each pair of cylinder ports last and right...and 8205 located on top of each rearmost push rod tube housing on case.
thanks
 
Engines

Most of the IO 320's installed on US manufactured aircraft were the Twin Commanche engines.
IO 320B1A
IO 320B2A
IO 320C1A
The 0 320 dash numbers on the top of the case are: -27 or -27A, -39(A), -55(A).
Most -39 are 160 hp.
-55 is IO 320
The dash numbers are series numbers and do not relate to individual models.
The Lycoming directory does not do a good job of documenting engine mount type.
I think the most likely scenario is that you have a Twin Commanche engine that was converted to fixed pitch configuration.
Also possible you have a completely different engine that was converted to fuel injection.
The above does not address the H series, AEIO series or counterclockwise rotation(L) engines.
 
numbers

Turbofan said:
Injection bottom mounted, where carb usually is.
Only numbers on case halves are located on top rear, just in front of access case....16780Q3 on both halves....72081 and 72082 are numbers between each pair of cylinder ports last and right...and 8205 located on top of each rearmost push rod tube housing on case.
thanks
Click to expand...

None of those numbers compute. Most are five digit numbers followed by a -27 or -39(A) etc. The A denotes a wide deck engine, technically described as a wide cylinder flange engine. The numbers should be on a flat machined on one side of the case, immediately adjacent to the junction of the case halves.
 
Called lycoming.....helpful
the between the cyl port numbers are case part numbers, left and right, the top rear numbers are casting I think he said, and on top rear of spine was unique serial, very small that I missed.
21235 27A
27 means originally carbureted, A is wide deck, and remaining is serial ID as E2A.
 
I've got an accomodation on lower right of access case for hydraulic pump (gear or flaps) or it could have been for a rear mounted prop governer , perhaps this was off early twin Comanche or Apache?
 
Engine

Twin Commanche did not have hydraulic pump. All four cylinder Apache engines are narrow deck and conical mount. -27 covers a wide range of engines. Fuel injection appears to be a retrofit, very common on EAB.
 
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