REPLACING FOX 35 on NOBLER ARF-RECOMMENDATIONS ?

[Frank Imbriaco]

I recently returned to Ukie after a 40 year hiatus. Continuing as an R/C Pattern flyer ,but I thought I'd dip my toe in once more to see how it goes. So I bought a Nobler ARF(coulda and shoulda choose something better) and thought I'd economize by using one of my Fox 35s from the early 70s. The one I chose was new and I decided not to lap it in like the days of ole'. I did bench run it for an extensive amount though.It's gone through a fair amount of 5% nitro/ 28% Castor S&W and some with 10%. Swapped out the NVA with one from R.S. It runs like any, stock  moderately broken-in- Fox 35s and it will probably get a bit stronger and friendlier with another 5 gallons of fuel and perhaps a hemi head kit. However,the plane seems down on power( weighs just 40 ounces ready-to fly without fuel), even though I clearly remember that my Fox 35s pulled my Detroit Stunter, Smoothie, and J.D. Falcon II -no sweat back in the 60s.

I've narrowed it down to a BRODAK 40 or one of the new Enya 40s(SS 40S or the 40 XZS) . The Aero Tiger 36 is intriguing, but it deserves a better mount than a Nobler ARF. I'm interested in which is the most thrifty with fuel as I can only squeeze about a 3.5 ounce Uniflow in the tank area as the plane is completed. Long story short, the stock plastic tank is unsuitable for U/C as it is an R/C tank- Had I known before mounting the wing, I could have put in a 5 ounce Uniflow with easy before -the -wing -is-attached mods.
I  would appreciate feedback on these engines and first hand knowledge of which would require the least amount of mounting modifications. I've already purchased a new cowl.
I really hope to not  debate Fox 35 engines- I love and continue to own some really perkin' Fox 36XBBs that were modded by Larry Scarinzi and I think the 4-2-4 sound is pure music.

[Peter Ferguson]

If you like the sound of the Fox and want a light motor the B40 is the way to go. It has a nice stunt 2/4 break like the Fox. Fuel consumption could be an issue though. You may want to downsize the venturi a bit to a .270 or so.  Try a Cyclone 11 x 4.5 with it.

[Tim Wescott]

What prop are you using?  What fuel?

I'm using a Fox 35 on my Nobler and it flies just fine when the pilot stays awake.  The plane weighs in at around 38 oz.  It goes plenty fast, and has plenty of tension in the wingover.  Judging from that yours should do just fine

I'm using 10% nitro fuel (whatever I win at the club raffle, plus some castor), and at the moment I'm running a 10-5 APC prop.

[Frank Imbriaco]

What prop are you using?  What fuel?

I'm using a Fox 35 on my Nobler and it flies just fine when the pilot stays awake.  The plane weighs in at around 38 oz.  It goes plenty fast, and has plenty of tension in the wingover.  Judging from that yours should do just fine

I'm using 10% nitro fuel (whatever I win at the club raffle, plus some castor), and at the moment I'm running a 10-5 APC prop.

Again, I don't wish to engage in a "why not the Fox 35"  type debate. I've used them extensively in the past and just want another, more modern powerplant.
BTW, I read your May 8 post about your preliminary flights on your Nobler/ Fox 35 combo following your experience with mostly 1/2A U/C aircraft. Good Luck and Success!

[Dennis Moritz]

It's iffy to use one of the OSs. Either an FP or LA. When run right they suck up more than 3.5 ounces for a pattern. LA46s are more user friendly than the FPs. But will often burn 4.5ounces or so when set up right. Try an LA40 with an FP25 venturi. Dunno. The fuel tank restriction is a bummer.

[Balsa Butcher]

It's not new technology but in my experience (others may differ) about the only .35-.40 engine that will do the pattern reliably with a 3.5 ounce tank is the OS 35S. As an alternative you might consider the modern .25 sized engines, 25 FP or LA, possible the Enya 30 (available from Randy Smith). All have more power than a Fox 35 and should do fine w/ 3.5 ounce tank. Don't look for a 4-2-4 run though.  

[Randy Powell]

I suspect on a Nobler that you could run an LA25 in a wet 2 and generate enough juice to fly a pattern fine and do it under the fuel limit you have. Depends on what your plans are. Any sort of more modern power plant that you are planning to use in the future on another plane will likely need more than 3.5 ounces. So you may be looking at a bigger tank either way. Even a Brodak 40 would be close in fuel unless you really necked down the venturi.

[Tim Wescott]

Long story short, the stock plastic tank is unsuitable for U/C as it is an R/C tank- Had I known before mounting the wing, I could have put in a 5 ounce Uniflow with easy before -the -wing -is-attached mods.

Wassamatta with a plastic tank?  Plumb it for uniflow, and away you go!

Granted, I haven't done it much, but to make an RC "clunk" tank into a uniflow tank, you just put a vent tube in there that moves with the pickup clunk -- either put in a separate tube with its own clunk (which is what I have in my Nobler), or wire the vent tube to the pickup clunk (which makes for a slightly more rigid assembly).

Either way the clunk will stay stuck to the outboard wall, and will follow the fuel up and down as the plane goes inverted/upright.

Works a treat.

[Martin Quartim]

Enya SS30 is a good replacement, almost same weight. I am sure you can set up up to use only 3.5Oz of fuel, Mine with the large venturi and APC 10.5x4.5 prop burns a bit more, but with a smaller prop and the stock venturi it may be the ticket.

Martin

[Garf]

I have a Kap-Pak 5 1/4 oz tank converted to clunk on my NoblARF. I don't even fill it half way with my OS 35S with ABC conversion added. Plenty of power. Pics are approximation of the design.
http://hangarflying.proboards.com/index.cgi?board=wire&action=display&thread=2426
Here are 2 pics of the profile version of the tank.
http://hangarflying.proboards.com/index.cgi?board=wire&action=display&thread=3416

[Tom Luciano]

Hmm, appears to me there may be more then a toe in the water!!
Great to see you here Frank!

Tom   

[Frank Imbriaco]

Hmm, appears to me there may be more then a toe in the water!!
Great to see you here Frank!

Tom   

Tom ,
It's all your fault, man.
Say hello for me to Sr. and Jr. We gotta get together  soon and fly R/C, Ukie, Indoor,whatever.- before the snow flies, eh ?

Frank

[Larry Renger]

I have a Brodak 40 with one extra head gasket.  Using 10-10-10 fuel and an 11x5 prop, it goes through the pattern on 3.5 ounces with plenty of punch to pull an ARF Smoothie.  The fact that you need way less oil in the fuel really improves the "gas mileage".

[Brett Buck]

I've narrowed it down to a BRODAK 40 or one of the new Enya 40s(SS 40S or the 40 XZS) . The Aero Tiger 36 is intriguing, but it deserves a better mount than a Nobler ARF. I'm interested in which is the most thrifty with fuel as I can only squeeze about a 3.5 ounce Uniflow in the tank area as the plane is completed. Long story short, the stock plastic tank is unsuitable for U/C as it is an R/C tank- Had I known before mounting the wing, I could have put in a 5 ounce Uniflow with easy before -the -wing -is-attached mods.

 I wouldn't limit yourself to 3.5 oz or avoid clunk tanks. The last Nobler/Fox flight I flew was using a 4 oz Sullivan round clunk tank because it ran much better than anything else. It's easy to get 6 oz in an ARF Nobler.

    But if you want a more powerful/less fussy replacement, there are plenty of options. Either a Rustler Merco 40 Metamorph or LA46 springs to mind, but the Magnum 32 or 36, a 25FP, Brodak 40, AeroTiger (best engine by far in this class and one of the best stunt engines, period), etc are all a big performance boost over a stock Fox and will fit.

      Brett

[johnbyrne]

It's not new technology but in my experience (others may differ) about the only .35-.40 engine that will do the pattern reliably with a 3.5 ounce tank is the OS 35S. As an alternative you might consider the modern .25 sized engines, 25 FP or LA, possible the Enya 30 (available from Randy Smith). All have more power than a Fox 35 and should do fine w/ 3.5 ounce tank. Don't look for a 4-2-4 run though.  

A Tower 40 with an APC 10.5 x 4.5 will fly the pattern all day long on 3 1/4 oz of fuel.  I have one in a Vector that has been using this fuel load since it was built in Nov of last year (one first place with it) and Mike Donovan has several that use the same and in one case a little less.  Not sure why but they run sooooo good.  I have five now

By the way, do a search for my posts on Stuka and you can see my ARF Nobler tank design that allows 4 oz in an unmodified plane.  The key is that the lines exit the bottom of the tank allowing the tank to fill from the back of the firewall to the wing.  I've built several to date and the one in my Nobler has put in about 200 flights with no issues.  Power is via an LA 40 on 10.4 x 4.5 and it takes the full 3.7 oz load to fly the pattern which is why the final design put 4 oz in the plane.  Funny thing is that the Tower 40 in the Vector is stronger yet uses 3/4 oz less.  Go figure.

Found the link for the tank.  Only thing required to install is to drill three holes to route the fuel line through the lower firewall.  No other mods to the plane required.

http://www.clstunt.com/htdocs/dc/dcboard.php?az=show_topic&forum=103&topic_id=316094&mesg_id=316094&listing_type=search#316172