Lycoming O-235-4 engine question

Zachary · **Posted:** Sat Jun 16, 2012 8:05 pm

This was posted on the EAA Forums, of which I am one of the moderators. Does anyone have any info that I can pass along to the original poster? Thanks for any responses!
-Zack

Lycoming O-235-4 engines
I have an 70% complete Lycoming O-235-4 (100 hp) engine. I am assuming this was a military engine as most military engines used the dash (-) numeral in the model number rather than a dash (-) letter. This engine is also unusual for a Lycoming as the the starter and generator are rear mounted on the accessory case.
QUESTION; which military aircraft used this engine ? I thought it might have been the Navy AE-1 or HE-1 Piper J-5 variants. However the TCDS sheet only references the O-235-B engine.
Any thoughts ??

The Inspector · **Posted:** Sat Jun 16, 2012 10:11 pm

Zack,
Here's a few that used the O-235, PIPER PA-12, 14, 18, 20, 25 PAWNEE duster, 108 COLT, Funk 'C', and Bowers original FLY BABY.

Zachary · **Posted:** Sat Jun 16, 2012 10:14 pm

Are there any that used the dash four specifically? I appreciate the help Inspector.

The Inspector · **Posted:** Sat Jun 16, 2012 10:18 pm

ZACK,
No not that I an locate quickly, but PIAGGIO in Italy license built them and there's a very long list of European well known light aircraft that used the engines. Look in GOOGLE under 'Helicopters using LYCOMING O0235 engine' and you'll find a fair sized paragraph of types including CAP.
Might try contacting LYC archives directly to see if they will help.

shrike · **Posted:** Sat Jun 16, 2012 10:26 pm

Does the engine have a sump with cast fins and a fifth engine mount? That would make it one the first (Pre WWII) ones before Lycoming really got into the letter thing.

The earlier (235C etc) engines are getting harder to find parts for. I'd go for a plain-jane O-235 L2C as best bet to actually use. All of them are prone to SB505 (or SB530) failures, which may not matter at all for a homebuilt

bdk · **Joined:** Sun May 02, 2004 1:16 am **Posts:** 11319

For the Lycoming O-435 in the L-5, you need to cross out the dash number and stamp a letter in its place to conform to the TCDS. Could this engine not yet have been stamped with the civil designation and still retain the military designation?

Enemy Ace · **Posted:** Sun Jun 17, 2012 12:14 am

look it up in the Type certificate data sheets on faa. gov
or look it up under airworthiness directives, they usually include aircraft models affected.

Enemy Ace · **Posted:** Sun Jun 17, 2012 12:23 am

Followup: interesting, the -4 does not come up as a listed engine. If the dataplate is stamped -4 I suspect that this was not an aero engine application, but instead was used on a military starter cart or other ground service equipment (GSE).
In other words technically not to be used on an aircraft as a powerplant.

But I could be wrong. That's happened once or twice.

shrike · **Posted:** Sun Jun 17, 2012 8:18 am

The O-290G was the common GPU engine. It has a distinctive mounting flange cast in at the nose end of the case. Readily convertible to a/c use, but even less well supported now than old 235's

love2gofly · **Posted:** Sun Jun 17, 2012 1:39 pm

Are you sure it's not an "-A" that looks like a 4?

bipe215 · **Posted:** Sun Jun 17, 2012 1:48 pm

The Inspector wrote:

Zack,
Here's a few that used the O-235, PIPER PA-12, 14, 18, 20, 25 PAWNEE duster, 108 COLT, Funk 'C', and Bowers original FLY BABY.

I believe the original Fly Baby (the one that crashed) had an A-75, replaced by an 85 just before the EAA contest. There are a few O235 Fly Babies around though. I flew a 75 horse FB for years and it is some fun, cheap flying.

Steve

mustanglover · **Posted:** Mon Jun 18, 2012 7:51 am

The O-235-4 engine was never a certified engine and is not listed on the TC Data Sheet (E-223). Nor is it an engine that can be converted to a TC'd engine.

The only engine close that can be converted (as noted above) is shown in the following note on the TC Data Sheet:

Quote:

NOTE 6. Approval of the following models has expired. No engines of these models manufactured after the date or with
serial numbers above those listed below are eligible for use in certificated aircraft. (The early production engines
may still be used in certificated aircraft or installed under a supplemental type certificate). Detail specifications for
these engines have been deleted from this data sheet. Such information can be obtained by contacting the Manager,
Propulsion Branch of the New York Aircraft Certification Office, Federal Aviation Administration.
Model Date Serial No.
O-233-A1 2-25-44 106
O-235, O-235-A, -AP, O-235-B, 12-1-47 4524-15
-BP, O-235-C
O-235-2 Identical to O-235-B. When engines of this model are installed in certificated aircraft, the corresponding commercial
model designation should be added to the engine nameplate.

Zachary · **Posted:** Tue Jun 19, 2012 2:35 pm

I let the original poster know about all the great info here, and he replied with this:

Embarrasment

I have to thank Zack for for forwarding this thread to the WIX. After reading the responses on the WIX, I went to the engine and pushed away the cobwebs and rechecked the dataplate. To my embarrasment, I found the engine to be an O-235-2 overstamped to a -B designation. The dataplate has an acceptance date of 4-10-43. Somehow I had this engine recorded in my notes as a -4. A thanks to the WIX folks that looked into this.

Zack; please pass this on to WIX.

Thanks again folks.

Zack

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Lycoming O-235-4 engine question

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