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

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

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

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

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

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.

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

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

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

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.

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

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!

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

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

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

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

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

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

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

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

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.

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

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.

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

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

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