Swift Continental C125/C145/O-300 Information

From: Dennis Mee (
Subject: Re: N3812K
I just came across an O300D I can get everything I need to make it work except for a prop I guess that could be a problem without changing the crank. I really don't need a vacuum pump since this will be a VFR restoration so I'll keep looking. Thanks, Dennis Mee

I have an O-300A with a B&C starter. It is 10 or more pounds lighter than the O-300D I removed. I like the O-300D engine, the case is a little "heavier" than the "heavy" case 125 & C-145, and the cam is better. The cylinders are better too - but that point may be moot because for a good overhaul these days you just buy new cylinders. They are about $600 ea., and a first class cylinder overhaul costs almost that much, so you might as well buy new ones. That push button starter is really nice! (with either the O300D or the B&C starter) Keep in touch. -- Jim

O-300 ENGINE QUESTION...  (3699)
From: Ed Lloyd (
Subject: Re: 0-300A
Howdy Jim,
Feel like I know you what with all the questions and answers I've read on the net. The question I have concerns the 0 300A engine. What are it's good points and what are the bad? I'm looking for a Swift and have two located, both with this engine. One has 337 hrs and the other has 915 SMOH. I would value your input . Regards -- EdLloyd

I like the O-300A, its the approved engine on the STC. I removed a "D" and installed an "A" with a B&C starter. The bad things are the cylinders are marginal for cooling and the lack of a controllable prop. I like one-piece props! (cheaper, and won't throw a blade and kill you!) I can live with the takeoff performance. My temps. are usually pretty good, my baffling is in good shape. I have the new TCM cylinders and am keeping my fingers crossed, there is a service bulletin out on them. I think the O-300A is the most cost-effective engine for a Swift.  --  Jim

O-300D QUESTION...  (4199)
From: Ed Lloyd <>
Subject: 0- 300D
Tell me what I need to know about the 0-300D. What are the good features and what are the bad? I know it has a vacuum pump capability. Does it have any other features that make it better or worse in your opinion, than the 0-300 A? Regards, Ed Lloyd

The O-300D is not STC'ed for the Swift, most are intalled on the O-300A STC with a field approval for the prop. The "D" and "C" have a different crankshaft flange. The best prop is a Sensenich 74DC-1-60. Some 172's used this prop, with a lesser pitch. Most are found on Beech Muskateers. Others have used the McCauley EM series prop, but it is not as good a performer. The vacuum pump is a nice feature as is the key start.  --  Jim

From: Greg Papendick <>
Subject: Swift STC
Well it looks like I finally know what I am going to do with my Swift engine problem. I wrote to you some time back about my problems with getting my 0-320 installation approved and about the new AD on the prop. I have found a FWF 0-300 for sale and I guess I will be using that (includes metal cowl). My Swift is pretty close to original except for the FWF, battery relocation, and one piece windshield. This would allow me to return the Swift to pretty much original someday. My question for you, do you know anything about the 3 different STC's available for the 0-300A? It seems to me that I read somewhere that at least one of these has a RPM limit to keep the horsepower to 125. I would like to make this installation as simple as possible.  Regards -- Greg Papendick N3252K

The best (and cheapest, $25.00) STC for the 0-300A installation is the Swift Assn. (Piedmont) STC. It does require a placard to limit the engine to 125 hp, but so what? 125 hp is 86% power for a 145 hp engine and the only way you can exceed that is at sea level with a climb prop. With the prop called for on the STC, a 73x59 McCauley, you can't pull over 125 hp. They addressed the 125 hp restriction in kind of a dumb way. For legal reasons, you need a placard "do not exceed 2270 rpm at any time". They left off "at full throttle". I have mine above the rt. windshield, instantly viewable, but if you aren't looking for it, you would never notice it. If you don't mind spending the money, Merlyn has a GW increase for a 145 that allows full power and allows several different props, McCauley and Sensenich, both lower pitched which give better takeoff performance. -- Jim

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