Franklin Engine

brien23

brien23

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Brien
Parts availability of Franklin engines, PZL parts not sure they are the same as the original and if they can be used. How do you get new cylinders to overhaul the old engines like a B9F, or 6A4 I see aircraft listed as overhauled engine how much of a overhaul can you do without new parts? How much longer can the Bell 47 with Franklin 6V4 power keep going?
 
You are not required to use new parts...serviceable, yes. The cases are sent off along with crankshaft and camshaft for inspection and machining. The sleeves in the cylinders, along with valve seats and guides can be replaced.

They overhaul these engines a couple miles from my home. Call Southern Aero and ask for Robert Still. 336-476-9094.
 
Doug Reid said:
You are not required to use new parts...serviceable, yes. The cases are sent off along with crankshaft and camshaft for inspection and machining. The sleeves in the cylinders, along with valve seats and guides can be replaced.

They overhaul these engines a couple miles from my home. Call Southern Aero and ask for Robert Still. 336-476-9094.
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If no one is making new legal replacement parts who is making the sleeves for the cylinders or valve seats and guides. Their can only be so many serviceable parts left Franklin has been out of the US for a long time and PZL parts are not the same for old engines. Don't get me wrong I believe Franklin made a good engine and I like the top cover on the engine and other idea's that Franklin engines had.
 
When I had mine, never really had a issue getting parts.
 
brien23 said:
How much longer can the Bell 47 with Franklin 6V4 power keep going?
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My info is a bit dated, but a 47 with a 6V4 will last as long as there are airframes to put that engine in. Never really had problems with Franklin engine parts. Older 47s have more issues with procuring airframe parts than Franklin parts. That core engine is used on various other helicopters and airplanes. On the Bell 47 side if I couldn't find parts would contact the Bell 47 Association or Scott's Bell-47 Inc for leads on parts/services. FYI: Scott's bought the 47 TC from Bell a number of years ago.
brien23 said:
PZL parts are not the same for old engines.
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I believe PZL owns all the Franklin FAA TCs so any parts they produce will be legal to install on US aircraft provided the importation requirements are met as described on the TCDS. Now whether PZL makes parts for all the Franklin models I don't know. Perhaps a call to Scott's or a shop that works on Franklins will get you more specific answers.
 
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Bell206 said:
My info is a bit dated, but a 47 with a 6V4 will last as long as there are airframes to put that engine in. Never really had problems with Franklin engine parts. Older 47s have more issues with procuring airframe parts than Franklin parts. That core engine is used on various other helicopters and airplanes. On the Bell 47 side if I couldn't find parts would contact the Bell 47 Association or Scott's Bell-47 Inc for leads on parts/services. FYI: Scott's bought the 47 TC from Bell a number of years ago.

I believe PZL owns all the Franklin FAA TCs so any parts they produce will be legal to install on US aircraft provided the importation requirements are met as described on the TCDS. Now whether PZL makes parts for all the Franklin models I don't know. Perhaps a call to Scott's or a shop that works on Franklins will get you more specific answers.
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I used to own a Bell 47G powered by a Franklin 6V335A. I do not believe that Scott’s Bell 47 is doing anything with regard to Franklin parts. The place to shop for Franklin parts is www.franklinparts.com. Susan Prall, the owner, is zealous about the Franklin engine, And I believe she has even gone so far as to get approval to manufacture certain parts.

Chris at Airworx Aviation does a lot of Franklin overhauls and might be a good source of information. www.airworxaviation.com
 
SoCal 182 Driver said:
I used to own a Bell 47G powered by a Franklin 6V335A. I do not believe that Scott’s Bell 47 is doing anything with regard to Franklin parts. The place to shop for Franklin parts is www.franklinparts.com. Susan Prall, the owner, is zealous about the Franklin engine, And I believe she has even gone so far as to get approval to manufacture certain parts.

Chris at Airworx Aviation does a lot of Franklin overhauls and might be a good source of information. www.airworxaviation.com
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Those two are who I would suggest calling as well. It seems like they’re doing the most with the Franklins at the moment.
 
Bell206 said:
My info is a bit dated, but a 47 with a 6V4 will last as long as there are airframes to put that engine in. Never really had problems with Franklin engine parts. Older 47s have more issues with procuring airframe parts than Franklin parts. That core engine is used on various other helicopters and airplanes. On the Bell 47 side if I couldn't find parts would contact the Bell 47 Association or Scott's Bell-47 Inc for leads on parts/services. FYI: Scott's bought the 47 TC from Bell a number of years ago.

I believe PZL owns all the Franklin FAA TCs so any parts they produce will be legal to install on US aircraft provided the importation requirements are met as described on the TCDS. Now whether PZL makes parts for all the Franklin models I don't know. Perhaps a call to Scott's or a shop that works on Franklins will get you more specific answers.
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Back it the 90's I had a Hiller with a 200 HP Franklin. It desperetly needed the extra 10 HP the later Franklins had. I thought they were good engines. Just not enough engine for the helicopter. It obviously didnt last as long turning at 3100 RPM at 30 inches of manifold pressure.
 
Scott MacMoyle said:
Back it the 90's I had a Hiller with a 200 HP Franklin. It desperetly needed the extra 10 HP the later Franklins had. I thought they were good engines. Just not enough engine for the helicopter. It obviously didnt last as long turning at 3100 RPM at 30 inches of manifold pressure.
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I had the 210 in a Bell 47G. It was under-powered, for sure, but it taught me to always be ahead of the aircraft. My original engine blew apart in flight due to a poorly ground crankshaft, but the engine that replaced it (rebuilt by the late Jerry Debs) was at about 400 or 500 hours when I sold the aircraft. Solid engine. Didn't burn oil excessively. Didn't leak much, especially after I put silicone rocker-box gaskets on. Compressions were good at the last annual before I sold it. To this day I miss that helicopter...
 
way back when I was doing all my training and was always at the airport, there was a guy based there that had a C172D with franklin conversion. I never really knew what that meant other then it was a "different" engine.... but he sure was proud of that thing. I remember he use to talk about how smooth it was. I flew it with him a time or two. He liked to use the vernier to twist the throttle in rather than pushing it it for takeoff...nice and easy like.... honestly though I couldn't really tell much different about it than the school's 172 I'd been flying. Guess I was too young and stupid to know any better.(?)
Looks like that plane is in IL now... I love that you can do N number lookups so easy now days....
 
Brad W said:
way back when I was doing all my training and was always at the airport, there was a guy based there that had a C172D with franklin conversion. I never really knew what that meant other then it was a "different" engine.... but he sure was proud of that thing. I remember he use to talk about how smooth it was. I flew it with him a time or two. He liked to use the vernier to twist the throttle in rather than pushing it it for takeoff...nice and easy like.... honestly though I couldn't really tell much different about it than the school's 172 I'd been flying. Guess I was too young and stupid to know any better.(?)
Looks like that plane is in IL now... I love that you can do N number lookups so easy now days....
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Many of the C-172s /170-B came from the factory with the Franklin 165-HP
 
Columbia Aircraft Services, located at N13, Bloomsburg PA, was the overhaul shop the Army used for the military (Sioux) 47. They overhauled a friends 47 engine 10 or so years ago. I believe they still do Franklins, as well as Lyc’s.
 
Tom-D said:
Many of the C-172s /170-B came from the factory with the Franklin 165-HP
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No Cessna has ever come from the factory with any Franklin engine, to the best of my recollection.
 
Tusayan said:
No Cessna has ever come from the factory with any Franklin engine, to the best of my recollection.
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the Franklin 6A4165 was available thru 1954 in both the 170and 172, all the 172s that were converted used a 220 Franklin (6)
http://www.franklinengines.com

look up N3477C note manufacture date
 
Tom-D said:
the Franklin 6A4165 was available thru 1954 in both the 170 and 172, all the 172s that were converted used a 220 Franklin (6)
http://www.franklinengines.com

look up N3477C note manufacture date
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Here is the Type Certificate Data Sheet for the C170, it lists the C-145 / O-300 Continental as the only eligible engine. https://rgl.faa.gov/Regulatory_and_...582c0586257ed20071150e/$FILE/A-799_Rev_55.pdf

Here is the Type Certificate Data Sheet for the C172, it lists the O-300 Continental as the only eligible engine for any C172 built before 1967. Lycomings were used from that date forward. https://rgl.faa.gov/Regulatory_and_...3357f6c86257ea4004e8ae6/$FILE/3A12_Rev_84.pdf

This web page shows the aircraft types that used Franklin engines from the factory. No Cessna is included. https://en.wikipedia.org/wiki/Franklin_O-335

Franklin engines have been installed on C170s, C172s and C175s under aftermarket STCs, but not by Cessna on certified aircraft.
 
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Doug Reid said:
Better go back and read tcds on C170...item 111 in back.
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Thanks for that - it's interesting and appears to reference a non-Cessna installation, as per the following, but was added as an eligible option to the original TCDS using mandatory non-OEM parts. Was this before STCs existed, but effectively an STC?

When this item is installed the engine mount, cowling, baffles, exhaust system including carburetor air heater and cabin heater, oil system, power plant instruments and markings, battery location, and other items must be changed in accordance with the installation instructions, drawings, photographs, and parts list approved for Green Flying Service, Eugene Airpark, 1953 Chamgers Street, Eugene, Oregon. Airplane Flight Manual Supplement, Item 402(g), is required when this item is installed in landplanes. Airplane Flight Manual Supplement, Item 402(1), obtainable from Carl Millard, Ltd., 307 Riverside Drive, Ontario, Canada, required when this item installed in seaplanes.

The following is noted to apply to item 111, indicating that the application was by somebody other than Cessna (the aircraft manufacturer), and that Cessna did not produce the modification, so it does appear to be a modification sold directly to owners by the companies noted above with conformity determined by an A&P IA (i.e a 337 signed and submitted after installation).

Approval for the installation of all items of equipment listed herein has been obtained by the aircraft manufacturer except those items preceded by an asterisk (*). The asterisk denotes that approval has been obtained by someone other than the aircraft manufacturer. An item marked with an asterisk may not have been manufactured under a FAA monitored or approved quality control system, and therefore conformity must be determined if the item is not identified by a Form ACA-186, PMA, or other evidence of FAA production approval.
 
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21.6 Manufacture of new aircraft, aircraft engines, and propellers.
(a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on a type certificate unless the person—

(1) Is the holder of the type certificate or has a licensing agreement from the holder of the type certificate to manufacture the product; and

I am not certain how many 172s were manufactured this way, I do know they are rare.
 
Most people understand that TCs and STCs require holder permission for use.

It'd be interesting to note where in the C172 TCDS or an C172 STC available to Cessna prior to 1955 that the Franklin engine was made eligible for certified installation by Cessna.
 
Tusayan said:
Was this before STCs existed, but effectively an STC?
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FYI: STCs came into play after the re-codification of the CARs into the FARs in the late 50s. Aircraft modifications/alterations in the CAA days were tracked differently and those methods were brought into the new FAA system. Usually any TCDS that starts with an "A" prefix will contain a "Specifications Listing" at the end of the TCDS vs a "Pertinent Data" listing in most newer TCDS that use a "number/letter/number" numerical system like 1A15. Its a quagmire of old and new regulatory systems.

EDIT: I went back and reviewed if my comments above were correct. I was off a little. The CAA TC docs that have the "A" prefix are considered a "specification document" (not a TCDS) in their entirety. Once the FAA switched to the TCDS format under the FARs the number system changed and the "specification" side was included within the Type Design and replaced with an "equipment list" to be referenced in the TCDS. ;)
 
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Thank you very much for that - very interesting info on the history of FAA STCs.
 
Bell206 said:
FYI: STCs came into play after the re-codification of the CARs into the FARs in the late 50s. Aircraft modifications/alterations in the CAA days were tracked differently and those methods were brought into the new FAA system. Usually any TCDS that starts with an "A" prefix will contain a "Specifications Listing" at the end of the TCDS vs a "Pertinent Data" listing in most newer TCDS that use a "number/letter/number" numerical system like 1A15. Its a quagmire of old and new regulatory systems.
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We see these licensed most times with the antique aircraft.
 
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