Lycoming O-320 in the Swift

I think I put Mike's success with '11Echo in a previous update but don't remember. Anyway, saw the following in the So-Cal Newsletter...

Mike Williams checked-out Jim Stribling, Columbus, Ohio, in his new Swift, N711E, sporting an O-300D and new polish. It lost fifty pounds by removing the O-320, constant speed prop, and Corbin cowl; and picked-up 15 mph, at 160 IAS at 4000 MSL."

LYC O-320 VS CONT O-300...
I want to comment on the above before all you O-320 Swifters run out and trash your engines for O-300s. I sincerely believe that 160 IAS at 4000 MSL is possible with an O-300D. Takes a good clean airframe and a tight cowl which 711E must surely now have. (Please Mike, tell me how ya did it!!!) I can speak with some authority about this O-320 vs O-300 issue because my Swift has an O-300 and my wife's has an O-320. When we are flying with the same RPM, our climb rates and/or cruise speeds are virtually indentical. However, I evny Erin's Swift because the O-320 allows the use of a constant speed prop. I feel that the extra takeoff and climb performance that the C/S prop gives her Swift outweighs, (no pun intended) the extra weight of the constant speed prop. You'll get that 150hp at 2700 rpm right from the get-go on takeoff. With the O-300, you certainly won't get that 145hp at 2700 rpm with a reasonable pitched (57-60) fixed pitch prop. I'd love to have a constant speed prop on my O-300 but that just isn't available... (Well, Continental did, I'm told, make a very small production run of an engine called the O-300E for a constant speed/reversable prop... for the Goodyear Blimp.)

You have to consider the type of flying you do and where you do it. In some cases the takeoff and climb performance gained with a constant speed prop is more of an important issue than all out cruise speed. If I had to start from scratch shopping for a Swift to buy, it would have an engine installation that allowed a constant speed prop. Then I wouldn't sweat those high density altitude takeoffs as much. Still, the fixed pitch prop Swift will perform in high density altitude conditions too but ya gotta really be careful. During my trip to Athens in '93 I took off from Alexander, NM with an 8,000' plus density altitude and 15 knot direct crosswind. Did OK because I didn't ask the ol' Swift to do anything before it was ready to and the runway length and terrain allowed that.

So the fixed pitch just does not perform as well and THAT limits your options when it comes to takeoff weight and performance vs safety. Kinda like the difference between taking a friend along to Lake Tahoe in the summer (O-320) or going by yourself (O-300). The next engine for my Swift will be one that allows a constant speed prop.

Just my humble opinion gang. I'd love to hear others.

FIXED PITCH PROP FOR LYC. O-320...  (10299)
From: Bill Doty <>
Long time , no contact !! As usual, I need info. ,,,, I am ready to purchase prop. for N80572 ... As you may remember I have a 150/160 h.p. lycoming engine...Thought you might have a recommendation on size and where to purchase. Also, what spinner would fit on the plane/prop combination. Polishing is coming along (slow) but getting there. Still have (1) wing , vertical stab. and rudder , plus some trim parts, to go ... Would like to plumb up the engine and start it , to check out the top overhaul job. then ready to reassemble the plane..Looking to be ready for next spring...As usual , thanks for your help.. BILL DOTY

I am presuming you are giving up on the constant speed because of AD 97-18-02, is that right? First of all, the HC-82XL is not necessarily junk, it can be inspected per the AD note. I have seen quotes from $600 to $1200 to do the inspection. The bad news is, many times (expensive) parts replacement is required and the time before the next inspection is rather short. (sorry I can't quote it, I haven't read the AD in a while, it depends on several factors) If you would want to get your HC-82XL inspected, I have one here that could be used for parts. (actually a HC-82VL, removed from an Apache) It looks perfect, but of course it needs AD 97-18-02 - that's why it was removed. If you want to go to a fixed pitch, I would use a 72" dia. and 59" pitch prop. I forget the numbers for a 150 Lycoming, but talk to a local mechanic, a prop shop, or the FAA for advice on that. You will need a field approval from the FAA. They have to consult engineering on every prop field approval, so it helps to contact the manufacturer and get their recommendation. A lot of spinners will work, figure the diameter you want, find a part number, then get it approved along with the prop. Look in the Aircraft Spruce catalog or some other aircraft parts catalog. -- Jim

Anybody have experience changing the 2 piece venturi to the one piece per the AD? I bought one about 4 years ago and it's still in the box. The casting is sort of rough and I was wondering if it is important to be smooth around the center ring. Does the modification help or hurt performance? -- Ron Williamson <> N3740K

It should not affect the performance but there have been reports to that effect. Read AD 98-01-06. Your IA should have a copy. If the casting is rough it can be smoothed with a fine file and finished with fine sandpaper, caution: Do not leave any scratches. The 2 piece venturi is legal now, if you inspect it at each annual inspection. -- Jim

While performing an oil and filter change, the mechanics noticed a significant crack in the modified exhaust stack at the "y" location where the individual manifold exhaust join prior to the muffler. Since this is significantly modified to fit a "Corbin" cowl is anyone aware of where I could obtain a new replacement as oppossed to welding this once again. Rich/N2328b

Rich: I sold my 150 hp Lycoming Swift 30 years ago and I guess one of the big reasons was I was tired of fixing cracked exhaust pipes! The best luck I ever had was putting a slip joint in between the cylinders so expansion/contraction wouldn't cause cracking. I investigated several production aircraft exhaust systems and I believe a Citbria system would have worked, but I never got around to getting one. Later, I picked up a Citabria system for a friend of mine and he installed it. I believe he had the same cowl that you have. -- Jim

From: Ed Lloyd <>
We see all kinds of engines advertised. Examples: O-320-D2A Lyc, O-360-A4A Lyc,IO-360-A,-C,-K Cont. Is there a site that will explain all that code so one knows what is in the engine and what to look for or stay away from? Maybe another way of asking is, which are the best engines for hanging on a Swift above 145 Continental? Cheers.......Ed Lloyd

You might look around at; but I have not ever found that exact info there. I wouldn't say they are "best" but the O-320A1A and O-360A1A are the "approved" models for several STC's. I don't know about the IO-360 Lycoming. The TCM IO-360A-C and D are used with the Maule type prop. The later models, such as the "K" have a different crankshaft and need a different prop. Call Merlyn to find out what combinations are OK.
What's best? Well, <g> it's gotta have 6 cylinders! -- Jim

LYCOMING O-320 (THAT'S ALL)...(120400)
Jim, Guess I am coming up a little short with a O-320...oh-well.. By the way, my engine only has O-320 stamped on the plate. NO suffix numbers?? Any help on what that means !! -- Bill Doty

Yes I do know what that means. The very first O-320's in the early '50's didn't have any suffixes. There was only one kind of O-320 then! Later on they designated a code for fixed pitch or c/s prop and/or other accessories and type of mounting. -- Jim

From: Terry Straker <>
Subject: December #4 GTS Internet Update
Hi Denis and all Swifers!
I saw Ed Lloyd's question re Lycoming numbers and have some info on the subject. I am slowly-very slowly- working on a Van's RV-6 (I know this is heresy for a Swift owner, but the ability to work on my own airplane without need of someone else's signature every year is very alluring to me) and in the plans section on engines there is a list of all Lycoming 320 and 360's made with dash numbers and what they all mean and what the engine has hung on it. Van's would probably supply these pages, or if not I could photocopy them. I have a 200 HP IO-360 Lyc in 31W and am very pleased with it despite the lack of those 2 extra cylinders the Continental boys seem to like. And at reasonable throttle settings it uses very little more fuel than the C-125 it replaced. It is, however, sometimes difficult to use "reasonable throttle settings" because as everyone knows more is always better! Especially on takeoff.  Terry Straker

From: John Lindley <>
Subject: Oil coolers are better on left?
This is the experience George Divanian and I have had in locating oil coolers. Both of our planes had Lycoming O-320 engines, but the moral will apply to any engine. The STC for installation of the O-320 placed the cooler on the right side of the rear engine baffle.

Some years ago George relocated his cooler to the left side rear baffle and reported much better cooling. A year or so later during some maintenance upgrades, I copied George's installation and got dramatically better cooling. With the cooler on the right, I could only do slow flight for 4 or 5 minutes before the oil temperature got up to redline. After switching to the left there was no noticeable temperature rise and no time limit to slow flight. Then we tried to determine why it worked so well. What was the magic in putting the cooler on the left? No magic - just dumb luck.

The STC placed the cooler on the right, horizontally with the inlet and outlet on the bottom. The oil flowed up into the cooler, across the radiator and then returned down to the engine. All of the oil drained out of the cooler when the engine was stopped so that the cooler was full of air. When the engine started, whatever oil pressure was in oil line would compress the air some, but there was no way to force the air from the top of the radiator. There would always be a bubble of air at the top blocking part of the radiator and oil flowing across the bottom. Also, any air in the oil flow could be trapped, thus increasing the size of the bubble. It is the same as the bubble in a bottom side up drinking glass in the dish pan. When the cooler was moved to the left, the coolers were mounted vertically because the hose connections were easier. The inlet and outlet were now on the side, one above the other. Also, just by luck, the bottom of the cooler was closest to the engine oil outlet and the top of the cooler closest to the engine oil return. We had a situation in which the oil flowed into the bottom of the radiator and forced the air out the top. Any air in the oil stream would just flow through the cooler and back to the engine.

The moral of the story is that coolers full of oil work better than coolers full of air. When determining the new location for your oil cooler, know the direction of oil flow through the cooler. Be sure that air is not trapped in the system, and will be flushed out by the oil flow. Hope this helps someone. Jack, Swift N2301B

LYCOMING O-320 STC...(060402)
Subj: Re: STC for Lycoming 150 HP 0-320 engine
From: (Mike & Gerald)
Dear Monty
I note that the prize for this year's competition is/was fitted with a Lycoming 0-320 engine, but I have not seen an STC for this set-up. As the saga of my aircraft continues, there is the option of this engine being available. I'd therefore be grateful to know whether an STC exists, if so, who owns it and the approximate cost. Also, what prop would be suitable? I'm still looking at the option of installing the 6 bolt crank into my 0-300A, and fitting the Sensenich prop offered by yourself, also am following up on the possible 0-300A crank form the Cessna 170 as forwarded to me by you and Denis. One way or another - ZS-BCE will fly this year! Kind regards, Mike

The STC for the Lycoming O-320 was originally the Corben-Fette STC and has been sold several times. It is currently held by Alterair and the contact information is on the Swift site. Click on "Swift Shops and Mechanic Listing" then Alterair in California. I don't know the current prices. I did one of these conversions over 30 years ago. The prop used on the STC is an old steel hub Hartzell and has a major AD note. Several more modern props have been used. The engine is the early O-320A (2B) The cowl is replaced with a fiberglass cowl, as a matter of fact, the whole firewall forward is replaced. This would be a very expensive conversion if all new parts were used. -- Monty

AIR BOX... (JAN 04)
I need a valid part number for the intake air filter for a GC-1B, IT has been converted with the Lycoming 0320 engine. Sincerely, Mark Jones

It depends on what air box they used. The original STC for the O-320 installation called for the same air box as a Tri-Pacer. I don't have that number handy but it should be easy to get. First determine what air box you have and get a filter to fit. This will be a little more problematic if you want to install a Brackett Air Filter, in that case call Brackett and make sure the p/n filter you want to use is Ok for a 150 Lycoming, then apply for a field approval from your FSDO. -- Jim

Subj: Re: Swift Newsletters
From: Terry Wills <>
I have a Twin Comanche which has the Lycoming IO320B1A engines and Hartzell 7663/4 Hub HCEZYL-2BS props. I have been wanting to install a counter rotating engine and prop on the Comanche and would like to use the above engine on the Swift. Have you heard of anyone using this combination and would a STC or 337 exist for the modification? Thanks, Terry

The engine from a Twin Commanche is not the one STCed for the Swift. The STCed version is the O-320A series with the straight conical mount. The Twin Commanche uses the O-320B series engine with (I believe) a type 2 dynafocal mount. It also is fuel injected. I believe Bill Walker in TX got a Twin Commanche engine approved in a Swift some years ago. He had to make his own engine mount and get it and the rest of the installation approved. I don't know exactly how he managed to do that but it is more effort than I would like to expend! I have lost touch with Bill but he lived on a private strip North of San Antonio and South of Kerrville. The Swift was N80799. I believe that Swift is owned now by Glen Estep of Devine, TX. -- Jim

Subj: O-320 Engine mount
From: (Wyatt Honomichl)
Hey Jim, quick question for you. Where is a good place to find a engine mount for a Lycoming O/IO-320 engine. Been looking for a while and didnt know if you knew a place that had one laying around. Thanks again for everything. Wyatt H.

The STC for the O-320 installation is held by Alturair in San Diego. Their contact info is on the Swift site. I don't know if they would make you an engine mount or not, I doubt if there is much demand for O-320 engine mounts. If you really want a mount for a 150 Lycoming maybe someone who has one laying around the hangar will read this and contact you. I would suggest installing a 180 or 200 hp Lycoming, it's no more work and the accessories and props are readily available. For example, the O-320 STC calls for a Hartzell HC-82XL propeller. This is an old steel hub prop and beside being almost extinct has a very expensive AD note which must be done every 250 hours. I reread your note and see you are also interested in an IO-320. The IO-320B is a 160 hp engine and takes an entirely different engine mount than an O-320A, which is the STCed version for the Swift. -- Jim