Bell 47 Franklin 6v-350 vs Lycoming VO 435

[crazedflyer]

I am in the market for a Bell 47 with wood blades. I have narrowed it down to the Bell 47G and 47G-2. The G has the Franklin 210hp and the G-2 has the Lycoming 260hp. What are the pro's and con's of each engine and which do you prefer? I definitely want the Bell 47, just not sure if I want the G or G-2.

 

Thanks in advance,

Kelly

[Whistlerpilot]

I learned how to fly in the Bell 47 G2 with wood blades. I don't think you would want less power, it's a heavy underpowered helicopter even with the Lycoming. I would avoid the Franklin engine myself. Why don't you arrange some test flights with each engine config and see for yourself.

[crazedflyer]

I would like to do that, but I have not found many around my area. I live in Dallas, TX and the elevation here is 600' give or take a little depending on where you are located. I currently fly a R22, but have always like the Bell 47's. There is a G for sale not to far from me is why I was wondering. I don't weigh much myself, only 140lbs. I would think with the low elevation and low weight I should be able to get good performance out of both, but I do like to hear others inputs.

 

Thanks,

Kelly

[iChris]

I am in the market for a Bell 47 with wood blades. I have narrowed it down to the Bell 47G and 47G-2. The G has the Franklin 210hp and the G-2 has the Lycoming 260hp. What are the pro's and con's of each engine and which do you prefer? I definitely want the Bell 47, just not sure if I want the G or G-2.

 

Thanks in advance,

Kelly

 

The Bell 47G and 47G-2 models are similar. The G2, was powered by the 260 HP Lycoming VO-435-A1 engine (derated to a maximum continuous rating of 220 HP) vs. the Bell 47G’s 200 HP Franklin 6V4-200 engine. However, due to the additional standard equipment installed on the 47G-2, like hydraulic boost cyclic control and its heavier engine, the empty weight also increased. So the increase in power yielded only a meager increasing useful load.

 

Wood blades were standard on the 47-G; however, hydraulic boost cyclic control servos were optional on the 47-G. Although the 47G-2 started with wood rotor blades of a laminated birch leading edge finished with spruce and balsa covered with a fiberglass cloth. Later models of the 47G-2 (G-2A/G-2A1) came off the assembly line upgraded with all metal main rotor blades.

 

Since both models are similar, the best thing to do is find who’ll give you the best price. Find out which engine is the easiest to maintain as far as cost and parts availability. Check on engine overhaul cost. Moreover, you have to evaluate the entire aircraft, not just the engine and blades. Are wood blades really the best option?

 

I would highly recommend you get in contact with or get a recommendation of a knowledgeable Bell 47 mechanic in your area. Whatever the cost it will be well worth it, in the long run, having a knowledgeable person go along with you during these aircraft evaluations.

 

Even if you’re an A&P mechanic, if you’re not actively engaged in Bell 47 maintenance, you’re at a great disadvantage. Over the years, there has been so many modifications, parts exchanges, overhauls, both legitimate and illegitimate, it would make your head spin. Not to mention, poor, missing, or pencil-whipped maintenance records.

 

The Bell 47 Helicopter Association may also be of assistance:

 

BELL 47 HELICOPTER ASSOCIATION SERVICES & DIVISIONS

 

BELL 47 HELICOPTER ASSOCIATION INC.

28931 BRINK RD.

CARLYLE, IL. 62231 USA

HOURS: 9:00am to 5:00pm CST. Monday through Friday. Please leave message on Saturday & Sunday.

PHONE: 618-292-9236

E-MAIL: ceo@bell47helicopterassociation.org

WEBSITE: www.bell47helicopterassociation.org

Edited May 13, 2016 by iChris

[Guest pokey]

this man claims to be the bell 47 expert of experts, don't know much about him, but well worth your time to contact him:

 

http://joeyrhodes.com/site/

 

 

and Scott's, has the type cert now, "the" source.:

 

http://www.scottsbell47.com/

Edited May 13, 2016 by pokey

[Canadian47]

Kelly,

 

Is there a reason you are insisting on wooden blades? The main advantage of the wooden blades they can be overhauled indefinitely. On the down side, they will likely require tracking twice/year due to changes in humidity. Keep in mind that most private owners fly ~50hours/year. I wouldn't ignore a nice Bell 47 with metal blades and a reasonable amount of time left on them.

 

Anecdotally (mostly from stories old timers tell me at fly-ins) the Lycoming is superior choice over the Franklin. My G4 has a Lycoming VO-540. I'm based at 3,000' ASL so a Franklin was not a good option for me.

 

Glenn

[crazedflyer]

I like the fact that the wood blades have no life limit just inspection and can be overhauled here in Texas. Also, some people I've talked to that have flown both of them say the wood blades fly better. Since I haven't flown either I have no clue, but just going off what I've been told. I can track and balance them when necassary so that's no big deal. On average I've been flying 200 hours a year. It's not a ton but a fair amount for a private use helicopter. Feel free to comment on any information that may be useful. Thanks in advance.

[rotormatic1]

I would go with the Lycoming engine. Back in the 70's, my first job was to tear down surplus engines for overhaul. Most of the Franklin's were tear downs to get cylinders to overhaul for exchanges. We would re-sleeve and overhaul the cylinders and sell them for top overhauls. Many of the Franklin engines we tore down had failed crankshafts (broken in two)....

 

Never took down a Lycoming 435 that had a busted crankshaft....

[crazedflyer]

Many of the Franklin engines we tore down had failed crankshafts (broken in two)....

 

Never took down a Lycoming 435 that had a busted crankshaft....

 

Do you feel that the Franklin's may have been ran above and beyond their limits or do you feel the Franklin is an inferior engine? I would have thought if it was too bad of an issue that there would be an AD on the crankshaft. Although there could be and I don't know about it. Thanks for the info.

[adam32]

Nothing "wrong" with the Franklin. The same engine is in some Hillers, even the turbo Franklin.

 

Get the helicopter in the best shape that is in your price range.

 

Parts for the Franklin will be cheaper also.

[Dragbrace]

To echo Adams ' post their is nothing wrong with a properly flown and maintained Franklin. To be more specific to the title of your post 6V- 350 vs. VO-435. The 6V-350 Franklin is rated @ 235hp vs. 225 for the standard VO-435. As Chris pointed out the Lycoming is a heavier engine. If you are considering a 47-G2 , get one with the VO-435A1F high compression engine it is rated @ 265hp and more than makes up for the weight difference.

 

As an old timer with many thousands of hours in both Franklin & Lycoming's doing ag work. I preferred the 210 and 235 versions of the Franklin to the standard VO-435. I preferred the VO-435 A1F over them all.

Edited May 15, 2016 by Dragbrace

[crazedflyer]

As an old timer with many thousands of hours in both Franklin & Lycoming's doing ag work. I preferred the 210 and 235 versions of the Franklin to the standard VO-435. I preferred the VO-435 A1F over them all.

 

Thanks for the post Dragbrace, have you flown both the wooden and metal blades; which one flew better?

 

Thanks

[Dragbrace]

The wooden blades were designed for low altitude and performed better than the metal blades at that task. The metal blades were designed for higher altitudes as the 47 matured and received more power to take them to altitude and they performed better at that task.

 

We quit using wooden blades on the ag ships back in the 70's ,mainly because the chemicals we were applying were hard on the finishes used in the day. In today's world, with the improvements in paints, resins and glues, I wouldn't hesitate on running wooden blades. For private use and if you hanger your aircraft you should have no problems. The key to maintaining a model 47's rotor system whether it has wood blades or metal is a good mechanic who understands the system and properly maintains it. Both blades fly well if set up properly. One other note, the Franklin engine is a smoother running engine than the Lycoming . However, it is hard to beat the power and torque of the A1F engine if that is what you are looking for.

[crazedflyer]

Thanks for the response Dragbrace, there is a 47G nearby that I am looking at with a franklin and wood blades. I believe this is the exact setup I want, just have to wait until my mechanic has time to go look at it with me. He has been maintaining jet rangers, but hopefully he will know a little about the 47's too.

[Dragbrace]

As mentioned before, buy the machine that is the best condition with the most time left to time retirement or overhaul. Don't get in a hurry to buy as there are still quite a few good 47"s left out there. They are just a bit harder to find than other models. Feel free to ask any more questions you have and I will try my best to answer them for you.

[crazedflyer]

Thanks Dragbrace, how important do you think it is to have the tail boom ultrasound tested before buying one. I have had a couple people mention to me to do this as they get corrosion inside the steel tube frames. Have you ever heard or experienced this first hand?

[Dragbrace]

The old tried and true method of checking for corrosion on the tail boom and center frame was to take an ice pick and push on any suspicious areas (bubbled or discolored paint) . Easy to do and usually a good visual inspection by a trained eye is sufficient. Just be sure you discuss it with the owner before you do any such actions .

 

If the 1200 hr. inspections on the airframe have been done properly you shouldn't have any rust or corrosion problems. The only consistent problems I've seen are aircraft left outside in extreme humid or rainy conditions. There again a good visual inspection by a trained eye will tell you a lot about the aircraft's over all condition. Check the logbooks to see if the 1200 hr. airframe inspection have been done regularly. Keep in mind that the oldest model 47's are fast approaching 70 years of age. That is a good testament to the integrity of the design if maintained properly.

[Mikemv]

Thanks for the response Dragbrace, there is a 47G nearby that I am looking at with a franklin and wood blades. I believe this is the exact setup I want, just have to wait until my mechanic has time to go look at it with me. He has been maintaining jet rangers, but hopefully he will know a little about the 47's too.

 

http://joeyrhodes.com/site/about-us/

[crazedflyer]

Has anyone actually ever used this Joey Rhodes? I've heard mixed things about him, not personable and tells you a lot of what you see and find on the Internet. No punches intended, just wondering. And $200 for his book, I'd rather put that towards a good mechanic.

[Jaybee]

Bell 47 article_1_Rev. 210.pdf

[Rupert]

I had a flight school and operated a G2 back in 1980. A nice machine. Not one to use for casual full-autos in training, but otherwise an extremely honest and well-behaved machine. It does what the performance charts say it will do, and no more. Good history site: http://www.heli-archive.ch/en/helicopters/in-depth-articles/bell-47g2/

[adam32]

Has anyone actually ever used this Joey Rhodes? I've heard mixed things about him, not personable and tells you a lot of what you see and find on the Internet. No punches intended, just wondering. And $200 for his book, I'd rather put that towards a good mechanic.

Never used him but have talked to him. Nice guy I thought, he answered my questions when I was thinking about a 47. I went with a Hiller instead since parts are 20% the price of 47 parts.