0-300-B engine

[n2582d]

Bruce,
The screenshot of the equipment list was from my plane, N2582D, not the one JW is looking at purchasing.

JW,
That's surprising to me that Cessna would install an O-300B and the standard fixed pitch prop. Interesting!

[voorheesh]

The original C-145 engine in my old 1950 Cessna 170A was overhauled about 20 years ago by a reputable California repair station that specialized in engine work. The original cases were saved but nearly everything else was new (Cylinders, Crank, Camshaft, etc.) I recall the shop manager telling me that the engine came out as an O-300 when we settled up. He may have mentioned that an O-300 and a C-145 were identical (don’t recall the exact model numbers for that airplane), but I remember him telling me the engine overhaul records (work order and engine log) would identify it as an O-300, with the same serial number and data plate as the original engine. In many subsequent annuals, no one questioned the legality of this discrepancy. There may be legitimate explanations for these questions. However, I wouldn’t minimize the importance of making sure an airplane has the right engine matched up with the right propeller.

[Richgj3]

I thought the C145-2 and the O-300 differed in that the sump and accessory case were different. The C145 having three bolts fastening the sump to the accessory case and the O-300 having five. I guess that would be transparent unless you were looking for one of those parts. Also it’s possible the change was not coincident with first 0-300

Still learning.

[voorheesh]

My engine overhaul happened a long time ago and I could be mistaken that he changed the engine number in the maintenance records. I do remember him telling me it came out as an O-300. Maybe others know how that could happen or what the actual differences are.

[Bruce Fenstermacher]

There ins no real difference between a C-145 and an 0-300 and Continental says so.

From the overhaul manual: Due to the similarity of the C145 and the 0-300 model engines, all references and instructions regarding the C145 engines shall apply to 0-300 engines, unless otherwise indicated, throughout this manual. Nearly every part can be interchanged on any model with the exception of things like the change in size of galley plugs over the production run and the 3 hole sump must be matched with a 3 hole accessory case.

The name change simply a marketing change. Prior to a given date in 1955 Continental used the engines horse power in their naming convention ie A-65, A and C-75, C-85, C-90, C-125, C-145, while their competition used their engines cubic inch which yielded a name with a more impressive larger number. What sounds bigger and better a C-145 or 0-300? They are the same engine.

[Richgj3]

Thanks Bruce.

Does that mean the case halves are the same for the 0-300 and C-145? I came into a C-145 case and sump in good shape. If the case is the same, that makes it more useful

[Bruce Fenstermacher]

According to the IPC the case halves for the C-145-2 and the 0-300 A are one and the same.

Screen Shot 2022-12-12 at 7.52.33 AM.png (21.46 KiB) Viewed 3170 times

Of course as I noted there may be inconsequential differences such as galley plug size or thread pitch.

The differences between the -2H and the -B and the others is the machining for the prop control lever they had which may or may not have been done on the -2 and -A case halves. But these still have great value as they could be used to repair the -2 /-A or to build a -2H/-B with parts owned from the -2/-A as all these can be used in a 170.

The differences in the -C and D compared to the to the others, I'm not sure off hand. But I'd be surprised to find they couldn't be overcome. For example if you had a C-145-2 with a bad case and you had a -C or even a -D case halves. Every internal part of the -2/-A can be used to build a -A or -D depending on what crank is used and other mods applied. In my example the -2/-A has an 8 bolt crank which has been approved to install in a -C or -D. And of course the-D had an angle starter which could be used if the resulting engine was made a -D or used on a -2/-A or -C with approval.

[jwlynnav]

I’m bugging you guys again, and may be putting the cart way before the horse. Since I still haven’t been able to get to aircraft and check it out (I have gone to check out an airplane before and got within 100 feet of it and knew I didn’t want it). With all that said here is my question. The engine is 0300-B with 1270 hours. Can this engine be overhauled? If so do you have any recommendations so I could get a quote? I kinda like to know what I might be up against, so I emailed a big western engine overhaul company and they responded very quickly. They told me this engine could not be overhauled because you can’t get parts for it. I said I thought it and 0300A and 145-2 are basically the same they implied you can’t get parts for any of them. Is this the case?

[Bruce Fenstermacher]

Right now you can't get parts for brand new engines. Overhaul time frames are starting at 9 months with warnings of most likely longer. Try getting a quote for any newer Continental or Lycoming.

For quite sometime major overhaulers have stopped overhauling engines they can not call the factory and order a new cam, crank or case halves for. Or one stop shopping with a list to one supplier. Yes, you can get parts for the C-145/0-300 family of engines. No the crank, cam and cases won't be new but reground/repaired. And when things were good you had to shop about to find what you needed because manufacturers didn't run these parts every day. And now post COVID it's probably worse.

The point we've tried to make as old engines go is that with the C-145/0-300 family, you have options. Because this is a 0-300-B does not make this a completely orphaned engine any more than any other C-145/0-300. Buying a 170 with a Lycoming in it doesn't fix this either.

If you're shopping for a 170, you must know you're not looking to buy a plane you can make a call and buy every part to support it. Hasn't been that way for years. And that list includes about 90% of the planes of any make or model on the market. We have trouble getting some new parts for brand new Cirrus SR-22s we maintain and the aircraft is still under warranty.

[jwlynnav]

Thank you Bruce. I understand I’m actually emailing overhaul shops to get ideas and estimates. Again trying to get as much information as I can to help in making a purchase decision.
Again thank you

[GAHorn]

Without reference to any claims of “Covid -related supply issues”….. new crankshafts are available I believe, in that the IO-360 crank (an engine still in production) is the same as for the O-300 engines.
New or overhauled cams are also reported available.

I have not visited with them recently, but based upon our enjoyment of our engine: Williamson Aircraft Engines of Florida overhauled the O-300-D in our Skyhawk and did an excellent job, exceptionally well documented, and a smooth-running, leak free engine.

Williamson Aircraft, 435 Herndon Avenue, Orlando, Florida 32803 (FL) (407) 895-0024

[dstates]

Poplar Grove Airmotive will do them and Airworx had been posting on Facebook that they have recently done some and they are continuing to get approvals to do more on O-300’s

[jwlynnav]

Thanks GAHorn and dstates

[GAHorn]

Thanks GAHorn and dstates

Keep in-mind that the IO-360 crankshaft is only a direct replacement for the O-300-C or D engines due to the prop-flange. If you use one of those cranks in a C-145 or O-300A or B…you will have to also change props to a 6-bolt prop such as the EM-series McCauley used on 172s (1962-68). This is what I have on my 170-B with O-300-C.

[jwlynnav]

I’m learning a lot in these conversations even though I haven’t purchased a 170 yet, but I’m certainly planning on it and maybe the 170 that started this?? So I’ve gotten 4 quotes ranging from 34 to 43 thousand and some have suggested switching to 0300-D. Wouldn’t that require STC and approval?