From: Horst Brinker <>
There's an ad in TAP selling 220 hp franklins for $14000. "brand new, faa certified" I believe there are some 220 franklin powered Swifts out there and I'm wondering if these engines have a simular low TBO as the 165 HP I had in my Stinson? Also, is the STC still available for putting these engines into Swifts? What prop goes with that engine in a Swift? Are there any constant speed props available? Thanks, Horst

Horst: I was hoping someone with more Franklin experience would reply. I believe the TBO on those engines is 1000 hrs. Contact Merlyn via the link on the Swift Home Page for STC availability information. The prop is a similar McCauley to the one used on the 210 Continental. It is a constant speed. -- Jim

Southern California Swifter Bill Babb sent the following regarding Franklin engines in Swifts:

I am currently converting my Swift from a C145 to the Franklin 6A-350-C1 220 HP engine. For starters, the engine has a 1500 TBO, and, if you get the Polish version, is rated 208 HP @ 2800 RPM. The reason for the difference is, that Polish law requires that the HP rating actually reflect what the engine is capable of. (Interesting concept, I would hate to think what Continental or Lycoming ratings would be). However, the engine is virtually the same as those manufactured in the US with some modifications due to manufacturing processes and procedures changes. The engine still qualifies as a certificated engine under the original FAA Type Certificate. As to the Swift STC, it is held by Merlyn Products of Spokane Washington. They have not sold any Franklin STCs for several years and are currently in the process of getting the STC re-issued under Merlyn Products as the holder (formerly Machen). Once that is accomplished, STC should be readily available. Any inquiries should be addressed to Suzanne Evans at (email) As to the propellers, the STC lists two, both McCauleys. The first is the 2A34C-22/SF84-10. This is the original prop approved for the STC and is becoming hard to find. The second is the 2A34C-201/90DA-16. This is the newer prop and is more readily available. I am installing the C-201 prop for two reasons. First, it's lighter. The C-22 weighs 50.3 Lb while the C-201 weighs 49.0 Lb. secondly, the C-22 retaining ring has to be drilled and pinned at assembly. This is done each time it is overhauled and can only be done four time before it has to be discarded. The C-201 hub retaining ring is not pinned and therefore does not have this limitation.

I chose the Franklin over the Lyc. 200Hp and Cont. 210Hp because it is a normally aspirated engine (no injectors to worry over), it has a higher Hp rating and it is very smooth running due to a viscous dampered flywheel. Everyone I have talked to has told me that Franklins are one of the best conversions for the Swift, the big problems being parts availability and the availability of the STC. I have not confirmed it but Charley Hart of Winfield Aviation told me that Maule will be offering the 220 option again. Also, there are two companies that are offering most of the major parts mostly from stock, including cylinders. They are Franklin Aircraft Engines and New Aviation. Both may be found on the web. I have my engine and the prop is currently in shipment, and I am anticipating that the STC will be available this month. With any luck, I should be flying by spring. By the way, if you want a real boomer, as of early this year, Steve Halprin had a 250 horse turbo Franklin FWF off his Swift for sale. If you have any questions, contact me at Bill Babb

(Thanks to Bill for sharing the info with us and also thanks to Suzanne Evans for getting the Franklin STC up and running again!)

From: Yves Starreveld <>
I gather Franklins are available direct from the factory in Poland. <> They would appear to be a substantially less expensive alternative to an IO-360. Merlyn has an STC and mount. Does anyone have any pro and con comments? Yves

I wouldn't say a Franklin is a bad engine, but it has several negative points, as well as several good points. It is a little heavy, is carbureted (some say that's good!), does not have crankshaft dampers and has a fairly low TBO. It is known as a smooth engine at its cruise RPM. The initial price is low. (for a 220hp aircraft engine) Local Swifter Harry Lyon had one in an older 172 and in the very next hangar Swifters Bob and Deb and Deb Bailey had a Cessna XP with the TCM IO-360. The Continental seemed to have more "real world" get-up-and-go. -- Jim

There are a number of Swifts running around with Franklin engines. I think that the Franklin engine is basically a sound engine design. I feel they got a bad reputation many many years ago, for a valve sticking problem which occurred due (primarily) to inactivity. I used to fly SeaBees and often they sat in humid conditions for months on end without flying. Compounding the problem was a dis-similar metal condition between the valve and guide which promoted sticking valves. In regular use, there was no problem. Also, the oil in those days was not great! I understand that later models of the engine incorporated different valve/valve guides or both, not to mention the modern AD oils. I do not know what the FAA/MOT might say about the Polish Franklins. You might want to look into that. Although they are probably a direct replacement, certification might pose a problem... Cheers, Steve "Never trust anyone with ten fingers" Wilson

FRANKLIN INFO...(120500)
From: Bill Babb <>
In response to the Franklin question on your current news letter, the Polish engine is approved in the US under the original Type Certificate and seems to be becoming more popular (along with availability). It appears that the home-built community is using these engines as an alternative to the Lycomings. As to the availability of the Merlyn STC, I have the mount but I am still waiting for the final paper work. It seems that the STC has never been reregistered to Merlyn Products from Machen. Suzanne (Evans) has said that she needs to complete the upgrade of the STC and get it reissued. As we know, the FAA moves in mysterious ways. As for my engine, I found a first run US engine and had it overhauled by Charley Hart of Winfield Aviation, and couldn't be more pleased with the work (although it takes a while as he is a one man operation). I chose the Franklin for two primary reasons, 1) It delivers a true 208 horse power (or so the Poles say), and 2) It is normally aspirated. I had an IO-470N in my Bonanza and I do not want to contend with the hard hot starts and fouled injectors. Other reason are: I have been told that the engine is very smooth. This is due to the viscous damper flywheel. Also, if you can believe what you hear, fuel economy is better than the equivalent Contenental/Lycoming engines. These latter issues are hearsay as of now, but I'll let you know in future notes what my real experience proves. -- Bill Babb

Subject: Re: December #4 GTS Internet Update
Dennis:  I just talked to Charlie Hart and his email address is As I mentioned in my earlier reply, he is probably THE authority on Franklin engines. He used to work at the Franklin factory and has held workshops at Oshkosh on the Franklin. He works closely with the Southwest Stinson club and told me that he would be glad to answer any questions, dispel all myths and provide advice to any one interested or looking at installing a Franklin of any size into their airplane. He asked that you include him in your news letter distribution. -- Bill Babb

From: Bill Babb <>
I can not stress enough, anyone thinking about a Franklin should do their homework. Talk to guys like Charlie who KNOW and then make a decision. As an example, in your last news letter Jim made several statements that warrant clarification. First, I don't know what a TCM io360n weighs, but the Franklin engine weighs 330 lb; second for me a carburetor is less maintenance trouble and fine for the average Swift pilot flying below FL 18; third, it does have a damper, the engine has a viscous dampened flywheel on the opposite end of the propeller which seems to me to be a better distribution of the rotation mass; fourth, as to the TBO, every engine (TCM and Lyc) has about the same wear characteristics, the difference being who is computing the times and what they are willing the advertise; fifth, as to get-up-and-go, I can't comment until I get mine flying.

As for Yves, first, the valve sticking problem was due to cast iron valve guides in the early engines, the problem was corrected by using bronze (or brass, I'm not sure), and second, any aircraft sitting inactive for months in humid conditions will have problems-guaranteed; third, the FAA has accepted the polish engines under the original Type Certificate. Personally, I am not advocating a Franklin swap. I only know, after a lot of research what's right for me. However I will advise anyone thinking about it should talk to Guys like Charlie, Hugh Evans (Merlyn Products 1 800 828 7500) or even Charlie Nelson. He and I had a conversation once where he said that the 220 Franklin was probably the best choice if it were not for the parts problem. Well, with the reintroduction of the Polish version, parts are readily available from several sources.

Some are Franklin Aircraft Engines (, A1 SERVICES 903 626 5115 (ask for Susan) and New Aviation ( I have talked to Maule, and they'll be offering the 220 as an option on the MX-7 in early spring. This will be yet another source of parts. Last but certainly not least, I talked with Suzanne Evans yesterday and she said that they now have one mount in stock and have ordered four more. I will be happy to talk or correspond with anyone contemplating the Franklin and at least share with them my experience and sources.  Again, do your homework. -- Bill Babb

Subj: Franklin engines
From: Adam Beckman <>
Do you know what the replacement for the 4886 style fuel pump is on the Franklin engine? Is there are parts list that lists all fuel pumps that can be used on those engines?? Thanks, Adam

I forget the part number but the replacement pump is available from Maule Aircraft in GA. -- Jim

Subj: Re: Franklin engines
From: Adam Beckman <>
Thanks for the information. I just called Maule and they said that it will be approximately 1200 dollars to replace and wont be available until late January. Thanks again, Adam

From: Tony Gadis <>
Subject: Franklin Fuel Pumps
Dennis, I thought you could pass this on, there is an approved mechanical fuel pump available through CJ Aviation in Florida for the 220 Franklin. My Swift has a Lycoming 200 but my other plane is a Siai-Marchetti s-205 with a 220 Franklin. This pump is US made and $650.00 vs $1100.00 or more for the PZL pump. CJ Aviation Ph # is 800-227-5772. The manfacturer is Weldon and CJ has the STC. Tony Gadis

Subj: Franklin-engined Swift
From: Jon Hutchinson <>
I should be very grateful for any advice you could give me regarding an ongoing problem with my 220 Franklin-engined Swift (s/n 2157, reg N333DK), currently based at Guntly Field 62C, near MKE, Wi. It has a history of high oil temp & low oil press; typical values stabilized in cruise are 90C/40 psi, with CHTs apparently normal in range 170-210F. A long taxi after landing may result in 100-110C, on red line, & 10-15 psi at idle. Probably because of this I have had to recondition 3 cylinders over the last 3 years. Primary and secondary oil coolers are at rear of engine, primary upper left, secondary lower right. Primary cooled by intake air separated from L bank of cylinders by a baffle. Secondary by a separate "chin" intake, 3 in. dia. via duct with 90 deg. elbow. Exit air from the primary has to pass around accessories & hoses at rear of engine (a lot of obstructions?) to reach the cowl flap, which is located between the 2 exhaust stacks. Secondary cooler has a separate outlet beneath. The engine is tightly cowled, total intake area approx 60, outlet area with cowl flap fully open 44 There some louvers on L behind primary cooler, and below cowling, but temp measurements at those points during static run-up to 2000rpm show they don't let much air out. I am advised that there is insufficient outlet area to enable an adequate airflow, particularly for the primary cooler. Pressure measurements at front & back of cooler during static run-up seem to confirm this. Can you advise on a solution? I am now considering the following possibilities: 1. relocating primary cooler to a lower position, installing a NACA vent intake on lower L front of cowl with a straight-thru duct to primary cooler. 2. rotating secondary cooler so as to eliminate the 90 deg turn in the inlet ducting, and putting in another NACA inlet for it symmetrically on R side at front of cowl. 3. increasing outlet area by widening the cowl flap to go beyond the exhaust stacks (which would then have to be lengthened) Alternatively I could try to find a new cowling with bigger intakes, and bigger outlet area. I should much appreciate your advice, and to know if other Franklin Swift owners have had oil temperature problems, and if so how were they solved: What cowl and oil cooler configurations do they have? Would an Alturair cowling be suitable for my engine? etc. etc. Thank you for any consideration in this matter. Unfortunately I am not able to get to the Swift National this year, where I could have perhaps got good advice, because of work commitments. Best regards, Jon Hutchinson

I wondered what ever happened to N333DK! You are practically next door to Lake Elmo, MN. Why don't you stop by and see us sometime? We have a Swift get together just before Oshkosh. I'm afraid I don't know much specific to the 220 Franklin. I have however, seen similar heat problems with other installations. I think you need more outlet area or just a bigger more effective cowl flap. By putting a bigger (and somewhat uglier) cowl flap on a 180 Lycoming the oil and cylinder head temperatures dropped significantly. On another IO-360 Lycoming the oil temperature remained high until the oil cooler was switched to the other side of the engine and replumbed so that it wasn't half full of air. Not having seen your setup, I can't give you any specifics. I doubt if just an Alterair cowl would give you the desired results. You need more air passing through the oil cooler(s). With your having to recondition several cylinders it sounds like you could use more air passing over them too. Why not try more intake AND exit area? -- Jim

From: "Owen, Larry" <>
Hi Jon, Denis
Not that this is a direct answer to your questions and I am far from a expert on this, but I do remember reading in one of my aerospace text books (many many years ago) that the outlet area must be 115% of the inlet area CLOSED and 150% or better OPEN to get any capacity through the radiator. If I read your email correctly, yours is about 70%. Naca inlet typically will not drive a radiator. Even Naca/Nasa has failed with that. I may not describe this correctly, but its something about the inlet pressure boundary flow breaks up with the backpressure of a radiator. I do remember that it will not work effectively, i.e. low flow if at all. Also the flow lines are very very sensitive to corners and seams. 90 deg turns are killers. My instructor said that if it didn't look like a sin wave or a wave on the ocean, it would not flow. That didn't help me much either, but the idea was to have painfully gentle turns and test / measure / test / measure / test etc etc etc. Pain in the empennage but it generally worked. My Cont 145 has about 100 sq inlet and over 140 fixed outlet just for the Cyl. A Franklin 220 is 50% bigger (heat wise) then that. I hope this helps, or at least reduces the number of guess's you have to make to get it right. Larry Owen N78287 El Paso, Texas 915-577-6832

Hi Larry -
Many thanks for your much appreciated advice about my overheating problem on the Franklin. Your info about intake & exit areas has confirmed my suspicions that those on my installation are grossly inadequate. I note what you say about NACA type inlets not being effective for supplying airflow to radiators, and about avoiding corners in the flow. It seems I may need to drastically modify (or replace) the cowling, and also re-do the plumbing. As you say ... pain in the empennage.... I am passing your advice on to Tom Guntly who is doing the work on my Swift at his field near MKE. Which aerospace text-book was it that you referred to? Seems I may need to buy, beg, borrow or steal a copy. If you have any further thoughts on my problem I should be very grateful for them. Best regards, Jon Hutchinson