What Engine for DF.?
 

I have a Top Gun F-15 and a Byron F-16. Both Have Byron Fans. These will be my first ducted fan jets. I need two engines for them them. What do you suggest for power.? Is the BVM .91 the best? Any help or comments would be appreciated.
Happy New Year to All,
Bob

What Engine for DF.?
 

BVM .91 doesn't have a large enough head for proper cooling on a Byron fan unit. Byron fans work best with OS .91 df engines. Be sure to get the ones with the large head for better cooling. TGA sells 'em at: www.tgajets.com

OS engines
 

Another option if you don't go the OS .91 route is the OS .77. If you look around on here or auction sites you can probably find one due to the fact that OS doesn't make them anymore. To bad because they were awesome engines!:(
Good luck!
Myles

What Engines
 

Thanks for the info. I was planning on using the OS .91 with large head. I have a pipe to fit it. Someone suggested a BVM. They said it puts out more horsepower. I was just wondering what you more experianced guys thought.
Thanks,
Bob

Engines
 

Like Terry said, the BVM does not have a large head so I would shy away from that engine even though they have terrific power. The OS .91 would be my personal choice. I have not had much luck running Rossi's.
Hope this helps!:)

Myles

What Engine for DF.?
 

Shy away, nuthin'. It WON'T work. It'll overheat, every time.
Get the OS91. Period!
Skip the Rossis, unless you have a good supply of trash bags you want to use up to keep your planes in after they fly.
The OS77 is fine, but it is out of production. Get the 91.

What Engine for DF.?
 

I've read in this column that the OS91 was out of production. Can anyone clarify on this subject?

What Engine for DF.?
 

Will the OS91 small head work ok with the Byron fan?

OS .91
 

Bob,
I have 2 OS .91's with the big head. One is NIB the other was in my Byron F-16 and only lasted a handful of flights, (but I am a much better pilot now). The used one has about 10 flights and has a RPM rod installed which is a Titanium rod ($50)to make the engine blow proof. Tower wants 319.95 I will sell you both for $500 check or Pay pal. :)
Sparky

What Engine for DF.?
 

Small head WILL NOT work with byron. You can buy the big head instead, but it costs some $60, I think, by itself.
OS91s are in stock all over the place, don't beleive all the rumors. TGA has them in stock, for example.
I heard that waigo hobbies in singapore is selling them for $255 shipped, I am going to try them myself.

NIB OS 91
 

Well I just sent off my mone order to a member here for my new in box OS 91 for 250:00 dollars which I thought was a darn good price. I also found a NIB Assembled Dyanamx for 150:00 again I thought was a decent price. I had no ideas that OS 91's where " Instock all over the place"
Viper

What Engine for DF.?
 

They are, but you got a good deal on both the engine and the fan, sounds good to me. The pair the guy listed above sounds like a good deal, too.
Have not tried waigo yet myself, but at least one of the guys around here did, and said it was just fine.
If you look up some of the "OS91 dead!" threads from a few months back, you will see the true story, we beat that subject to death!

Rod
 

Now my only question is should I install an RPM Rod in my new engine before it goes into my yet to be built JHH Phantom. I have heard/read that the new 91 engines have better rods than previous. Any truth to this guys? I hate to tear apart a brand new engine. :(
Thank Viper

What Engine for DF.?
 

Put in the RPM Rod if you can get one........... The guy that made 'em........ quit makin' 'em....... :(

RPM Rods
 

I cant get them Terry as far as I can tell. I am hoping the motor wont throw a rod and destroy itself. I guess I will just not run it lean and use good qaulity fuel. BTW Which fuel should I use in my 91 and my new 46VX does anyone know?
Thanks Joe

Big head
 

This seems like a perfect spot for this. I think I have an extra big head for an O.S. 91 if you need one I'll send it to you for free.
Scott

What Engine for DF.?
 

In the USA, it seems that the fuel of choice for the OS 91 is Wildcat Jet A (5%). I have been using this with my .91 in a Dynamax with excellent results.
As for the 46 VXDF, 95% of the folks I know who are running this engine (including myself) are using Wildcat Jet A (10%).

If you do a search on this subject, you will find that there is no correct answer to your question(s). There are many choices of fuel and it all boils down to what is available in your area, and your personal preference.

Peter

What Engine for DF.?
 

EASYTIGER said:
"Small head WILL NOT work with byron."

I usually stay out of these discussions, but sometimes I just can't help myself when someone is so emphatic about what will and will not work when my real world experiences are the opposite. I flew three Byron F-16s for six years. I flew a Regal Eagle for 1 1/2 years. I had two Top Gun F-15s, and one Byron F-15 twin. All of these had Byron fans. With the Dynamax fan I had two Yellow F-16s, two Yellow F-18 twins, and one BVM Aggressor with an OS .91 in a Viofan. At one time I owned 12 OS .91 engines. Only two of them had the large head. My flying buddy Vernon had more Byron planes than I had with a comparable number of OS engines, and his experiences are similar to mine. In my experience, the small head OS .91 engines will run fine in a Byron fan with the small head. Whether you use them in a Byron fan or a Dynamax fan, use red loctite on all the case screws before running. This will greatly improve reliability. Also contact Tom Cook for a heavy duty throttle arm. It is only a matter of time until the stock one breaks. Peak the engine out, then back off until you get a good smoke trail and let her rip. Wildcat 5% fuel with 20% oil will give great top end with a really good idle and transition. Also, I have never slung a rod in an OS.91. Just don't run it lean and you won't have a problem.

Good luck,

Dennis Lott

Remote Needle valve
 

Okay I have just one more question. I have heard that I need to buy the Tom Cook Remote Needle valve for both of my OS Engines, My 46VXDF and my 91VRDF. Does Tom Cook still make these needle valve and should I have them set up for control from the transmitter during flight? Also if anyone has Tom's website URL Could you provide it.
Thanks Very Much guys for answering all my questions. Its really appreciated.
Joe

Re: Remote Needle valve
 

Quote:
"I have heard that I need to buy the Tom Cook Remote Needle valve for both of my OS Engines"

I never used a remote needle on my OS engines. I did use them on all my Viojets, but when I used it, it was to set the needle on the ground before flight. I rarely used it in flight unless we were competing for the top speed trophy at an event in the d/f days when we still did speed.

Hope this helps.

Dennis Lott

What Engine for DF.?
 

I don't mean to be argumentative...but you really need a large BYRON HEAD engine for your BYRON plane. That's why they make the large head engines.
And get a remote needle valve. The vast majority of DF flyers would agree. It can save your plane and save your engine. The cost of a remote needle is a lot less than a burnt up engine, or a new airplane. The Cook one is good, but I think the BVM one is better, just easier to use.

Remote needle Valves
 

Can I ask? By the term remote needle are you talking about the one that Tom Cook sells that is adjustable in flight? And can I use it both on my OS 46VX and OS 91 VR engines, I read on Tom's site that you set the needle on the ground and then you can adjust the needle in flight from your transmitter via another servo.
I also read about his pressure vent for the fan that pressurizes the fuel system instead of using pipe pressure, is this the better way to go?
Thanks Guys
Joe

What Engine for DF.?
 

Yes. Adjusted with a servo. Thing is, if your engine goes lean in the air, and you don't have it, goodbye $160 piston and cylinder, and maybe goodbye airplane. Plus you can do stuff like lean it out for a little extra performance on takeoff, and richen it up again for the rest of the flight. It has saved me many times.
Pipe pressure versus fan pressure, big debate, but either one works. I have used both, have no real preference.

Byron Head
 

Originally posted by EASYTIGER
I don't mean to be argumentative

Sure you do.

Then you said.

...but you really need a large BYRON HEAD engine for your BYRON plane.


Well Flyguy, I guess you should get a BYRON radio and BYRON engine for your BYRON plane also. Sorry, but I couldn't resist. One of the reasons I prefered the small head was because I could use it with a Byron fan or a Dyanamax fan, but either one will work. The remote needle isn't a bad idea. It does allow you to correct a needle that wasn't adjusted properly on the ground.

Best Regards,

Dennis Lott - my real name

Remote Needle
 

I just looked at the Violet Remote Needle and its the one I will buy for my engines as it has a regular needle valve adjustment and then I can connect my Mini Servo to the valve for inflight adjustment. I also believe its worth the 42 bux to keep me engine running rich the whole flight.
Thanks Much for the help
Joe :cool:

Dennis being that I am building my first ducted fan right now I will install the Violett remote Needle so I dont smoke my new 46VX. And then I will put one in my Phantom for my 91 so I wont smoke it either and thanks much for your help Dennis I was looking for this type of needle from the start.
Joe

What Engine for DF.?
 

Dunno. Not looking for a fight over this, just want to help the guy with my own modest, limited experience, which includes frying one Rossi 81 and one Rossi 65 small heads in my first Byron F16 before I got the right engines.
I guess OS and all the other engine manufacturers felt it was important enough to make two head castings and two versions for all their ducted fan engines, and while YOU may have had luck running Byron fans without the larger head, I think OS, Byron, and the majority of Byron pilots would just say to get the larger head.
Anyway...it's not something worth fighting over, is it? You can have your opinion, too.
Good luck, viper. What is the VX going into?

Jet Hangar Fury
 

Hi Tiger, the 46VX is going into a Jet Hangar FJ-3 Fury/F86 but I am building the Naval version. It will have flaps and speed brakes along with the normal functions. I already have everything for the plane but some servos and the front nose strut. I have the main gear oleos and even the drop tanks for it but they will be for show. My second plane will the JHH Phantom with the Dynamax and OS 91. Which I just bought and it will have the scale landing gear struts and wheels.
I just started my turbine fund. I am putting away a certain amount of money each month for a turbine and plane and I plan to fly these two planes for 2 years and get my waiver and turbine and scale plane for it.
Thats my plan anyway
Thanks Joe

What Engine for DF.?
 

EASYTIGER is absolutely right. Even if it's true that some have had luck getting the .91 small head engine to work in a Byrojet fan, it's not supposed to. I'd bet that the small-head engines running in Byrojet setups have a lot of visible signs of overheating, too. Use the large-head for Byrojet applications. There is a good and simple reason for it--the small head doesn't have enough cooling-fin area to dissipate that much heat. The cooling air that the vacuum creates is a fraction of what it is in a tractor-fan setup. How do I know? Burned up an engine back in '93 because I didn't want to buy the large head, even though three different people told me to. Good luck!

What Engine for DF.?
 

Both of those aircraft are great, the JHH F86 is a perfect first jet. Don't forget, Larry Wolf, the JHH guy, is ALWAYS willing to help you out, if you just email or call him.
With the VX, it ought to be spectacular.
If you ever buy a YELLOW aircraft, Shawn Evans will always do the same!

Good plan, by the way. The world needs more SCALE modellers!

JHH
 

Yup Easy, I have known Larry for some time now and he is helping in the construction of my Fury( helping with the speed brakes) He's always been very good to me and I love both Fury's and Phantoms. The turbine I want is his big F15 that is Avonds design. I am thinking of a 30-35 pound turbine but that's a long way off, I will be happy to just get my Fury flying.
Thanks Viper

large head OS91's
 

I also have had considerable experience with the Byron kits and OS91's. I have not had ANY luck when using the small head in the Byrons....period.

I only tried it in 3 of his planes, F16, Mig 15 and the Bullet. All had overheating problems until the large head was installed. An in-flight (BVM) was used on all of them and extra Castor run in the fuel too....

I have found it hard enough to get them to run cool with the large head----4000+ ft altitude most of the time.....Dennis must have the velvet touch to make it work without them......

I am now following "Jackjets" style and adding 6 to 8 oz of Castor to each gallon of fuel for the Byron fans and am having better luck keeping them running with a lot less overheating problems.

Just my experiences....

Rod Springer

Fuel
 

You know, I was curious about adding castor oil to my fuel as well. I don't know where to get Wildcat fuel here on the West Coast (Southern California) I ussually fly Power Master 15% Nitro and I add about 3 ounces of Sig Castor too each gallon of fuel. This is just for my regular sport engines. I add about an ounce more to the Powermaster 15% 4 stroke fuel and so far I have had no problems burning up an engine but I don't know what to run in both my OS ducted fan engines if I cant get the Wildcat Jet A. Can I run the Powermaster with the increased Castor oil content in them or should I look for some other type of fuel.
Thanks Joe

What Engine for DF.?
 

I've done just that with the 91, spiked powermaster with some castor. Works fine. But the Wildcat seems to run a little better...at least it makes me FEEL better. With BVM stuff, I only run the wildcat. Order up a case, it goes pretty fast. Or call wildcat and find a local dealer. Call before visiting, though, because just because they stock wildcat does not mean they have jet-a.


But..5% works best for the 91. Don't know about the VX. More nitro on the 91 just leads to more blown plugs, not more power. At least that has been my experience.

oil in the fuel
 

Easy Tiger is right.....5% seems to be what the OS91 DF likes..I use the McCoy 9 plugs and now that I am using the huge amount of extra castor oil ( seems like it to me anyway ), the plugs are lasting longer too...

I have been using Byron fuel....same problem finding Wildcat locally, or when I need fuel at the moment.

Oh---one other thing I forgot to mention, some time back there was some discusion about Larry Wolfe always adding an oz or 2 of " turbine oil " to his DF fuel. I am doing that also. So 6 oz of castor and 2 oz of turbine oil is what I have started playing with at the higher altitudes--seems to work just fine--better than before anyway.....


Rod Springer

What Engine for DF.?
 

I'm not trying to pick a fight either. New guys need help from those of us who have the experience to answer their questions. I usually don't have much time to surf the internet because I am working too hard trying to afford my addiction, I mean hobby, but sometimes I feel like pitching in. My buddy Vernon Montgomery and I have each flown ducted fans for over fifteen years. That is over 30 years combined experience (gee, we must be getting old) with Byron jets with Byron fans. We have had a total of 19 Byron d/f aircraft. A total of 24 OS .91 engines, and five Rossi .91 engines (the original Rossi .91, which was a fantastic engine). Only four of the OS engines had the big head. We NEVER had engines that showed any signs of running hot. This is literally after flights that number in the thousands between Vernon, myself, and my two sons, and we fly in the worst of conditions, i.e. we live in the HOT, humid, sunny South.

If you take time to learn how to adjust your engine, you won't have problems. Don't take time, and it won't matter what kind of head you have on it.

To Shaun and EASYTIGER. I am sure you have many years experience with Byron equipment. I am sorry your experience wasn't as good as mine.

Since $60 is peanuts in the jet community, get the big head. Then you will feel that you have done the best you can do.

Viper21 has the best solution: Go tubine :D :D

One thing is for sure, I LOVE America. We all have the right to voice our opinions, and can do so without getting shot!

Long live the Red, White, and Blue!!

'Nuff said,
Dennis Lott

What Engine for DF.?
 

Just one more thing...it is not $60 for the head, if you are buying a new engine, usually the two are the same price or $10-20 different. If you have to CONVERT it, it's $60. But usually you can find one for sale for less. I gave one away a few months ago.

Fuel
 

Well, I am a ways off from really having to worry about fuel as I am still building my Fury. I just finished sheeting the wing panels and the center section. I am planning to try a pair of those new Hitec thin wing servos for the ailerons on my Fury, I am going to install one in each panel and then one HS 85bb on each flap. So I should have plenty of power and speed. And I am using one HS 85bb on each speed brake in the fuselage between the thrust liner and the fuselage. I will run a metal geared 85 on the nosewheel steering and the rest of the servos will be full size high performance servos except for the Needle valve and the throttle. For those of you that like Fury's here is my color scheme for my plane.
Thanks Joe

OS 91
 

I have been flying OS 91s for several years now with NO problems. I use Wildcat 5%, MC-9 plugs, and set it rich. Runs like the proverbial Swiss watch, never a flame out, even when the pipe blew out the back of my Cyclone. Treat it right, and it will run just about forever.

What Engine for DF.?
 

Whats a "Tubine"? Does that involve using a "Tub" pulled behind a boat? Hee Hee ;) :confused: :D

Just kidding, Dennis.

Engine type?
 

I know little about jets and nothing about helicopters so here's my question. If you need a large head for cooling in some applications why wouldn't a heli type engine with the bigger head work? Some are rated for up to 18,000 rpm.