Eagle Flyer

My Feedback: (84)

If I use an undrilled mount I need to know the clearance between the impeller and the stator. Any one know what it should be?
Thanks

Adil Nasim

My Feedback: (61)

I'm going by memory here but I remember Byron advising me to get the clearance as little as possible. I remember taking the impellor and sanding it face down on a sandpaper laying on a flat surface to get it even (it is slightly off in most cases) and then taping a piece of the same sandpaper to the impellor face while mounting the engine. Once in position, mark for bolt location.

The less the clearance, more the performance.

Hope this helps.

Adil

John Redman

My Feedback: (8)

Just like Adil said. This seems right, but it has been twenty years since I played with Byron stuff. I seem to remember you had to silicone glue a small plastic shroud to the stator area to help fare-in the engine to the stator to the mount, and this was set up to be as close as possible to the rotor when glued on.

Eagle Flyer

My Feedback: (84)

Yup, there is a cone that helps direct the airflow. Silicones to the engine. I also have a question about the OS 91 needle valve enrichment setup. A lot of people seem to recommend the BVM unit instead of the OS one. Is this because of the fact you can still adjust the needle without unhooking the device or is it because the OS unit only gives you as much as you can get with a servo hooked to it? I am guessing the BVM unit is similiar the factory one on a Rossi engine with a courser thread giving more adjustment. I have never seen one except for pictures. Some of the "ole timers" never used such a thing. They just set the engines rich instead of trying to squeeze every rpm out of them.

grbaker

My Feedback: (29)

The OS needle gives you very lttle range. The JMP or BVM needles work better.

donniercjet

My Feedback: (10)

lay your shroud on your table with the motor mount bolted to it place a card (playing card ) in the shroud place your motor with the fan bolted to the motor set the fan in place on the card (the card is a shim) with the motor on the lugs it will be vertical use your gp engine mount locator to center the holes from your lugs to the mount once everything is bolted in place pull the fan in and out to check your end play remove the glow plug slowly turn the fan pulling on it through the shroud to make sure nothing rubs if it does lay a peice of sand paper on your bench and draw the face of the fan across the paper dont rub it back and forth just pull it across one way that should get you with in about 40/1000 the thickness of the card good luck donniercjet

dbateman

My Feedback: (31)

Byron Fan? why bother? Even if you get your tip clearance minimized the pusher configuration will kill you. The ICDF tractors are bad enough but when you feed a fan with turbulant air your power loss will increase with speed. Thats why they have good static thrust but lumber around the sky.Pick up a Violet unit or go EDF or turbine. I know I'm ranting here but I get nuts when I still see these units around that were based on designs that ignore every rule of aerodynamics and ducted fan design. Doug

donniercjet

My Feedback: (10)

whats the difference between a tractor fan and a violet fan?? you still disrupt the air flow or the thrust when a motor is in the way in the root of the thrust tube

grbaker

My Feedback: (29)

Actually, neither one of these choices would be very good in an airframe designed for the Byron fan. Both would require extensive modifications of the inlet and tailpipe areas. Both are very expensive and neither would fly the airframe any better than the Byron. Byron powered airframes are typically larger than other DF airframes and they need the static thrust to fly. If it were possible to use 2 fans (like a Byron F-18), then that is different and either choice would be possible although even more expensive.

The Violet fan is a tractor fan, as are the Dynamax, Ramtec and most EDFs.

dbateman

My Feedback: (31)

Your correct , but the Viojet has an aerodynamic shroud designed to minimize the thrust losses on the pressurized side of the rotor. It provides flow around the cylinder head while still allowing for cooling. Exhaust velocity on these units is 200 mph+ which equates to a nice top end speed. I don't mess with gas ducted fans anymore as I found them to tempermental. The electric ducted fan is going to save non-turbine scale jets from a slow death. I have a Jepe F-16 that does 150mph and slows down to a crawl for landing. With brushless motors and lithium polymer batts. there's no end in site. Doug

donniercjet

My Feedback: (10)

donniercjet

My Feedback: (10)

sorry clicked wrong button........... how do you see that?? when did non turbine scale gas jets start to die?? whats it cost to put a electric fan assembly in a jet?? byron fan 100.00 rossi 81 or o.s. 91 225.00 (thats on the high side) gallon of fuel 15.00 flight times 10 to 15 mins. down time 15 mins (refuel, check batt (after 4 flights) have a smoke, start , fly for another 10 to 15 mins) i can put 15 to 20 flights on my byron mig-15 in a 4 hour flying day and thats charging the batts. at the field how many flights can you put on your electric in a 4 hour flying day?? why would i put a lithium poly battery in a 1000.00 jet that is so unstable thet it could explode when you charge it and take out my jet that i spent 6 months of my time to build?? sorry electrics are not going to cut it for me donniercjet

dbateman

My Feedback: (31)

donniercjet, your doing good if you have the kind of reliability you say.The Mig is a nice flying plane and it sounds like you do your homework. I'm just going by what I saw all summer at my local field. We have 6 guys with fans, probably a dozen jets between them. I think we saw maybe 4 successfull flights. Most can't get airborne and when they do it's a dissaster. Thats whats nice about your Mig, plenty of static takeoff thrust. The problem is these guys don't pay the proper respect to installation and maintenance and it shows at the field. Don't dis the electrics, I felt the same way you do a year ago. We fly all day, I get 2 six minute flights on the F-16 and then an hour recharge to repeat. At the speed it flies believe me thats plenty for my old eyes. We fly gas warbirds also so I get a full days flying in. With a quality charger the lipo's have never given us a problem. All I know is me and my son fly and fly and fly while our buddies tinker and curse. I wish we lived closer, I know you would get a kick out of the Sniper and F-16. We're all JET guys!!!!! Doug

Jackjet

My Feedback: (1)

DBaterman,
I have built AT LEAST 20 Byron Jets and they CAN be made to go fast - how about a Mig 15 and A-4 - radar clocked at 160mph - straight and level - full set of gear doors- Rossi .81 with OS .91 carb. and JMP in flight NV assembly- sprite soda bottle fuel tank set up- other mods.......it is what you do to them that counts.......Byron jets are good.

Jackjet

Falcon 64

I`m tempted to say the Gleichauf fan is much better than the first fan ever, the original Byron.

Both are tractor fans, but Byron hasn`t the pitch to match top speed. Thrust at static yes, but not speed..

I`ve had them both, one the very same model, the same engine, and there is no doubt at all.
If you can install a Ramtec, this will get you as far as you can get in DF, as long as the engine is top match.

As they say, cents bla bla..

G

reo

My Feedback: (130)

In short, the Byron fans may have been a bit bulky and antiquated (by later standards) but they worked well and did well in the market they were intended for.

Ron

Eagle Flyer

My Feedback: (84)

A person can't help but wonder where they would be today if they had stayed in the business and advanced with times!!!!!
Here's a picture of the Mig I am finishing up.

Falcon 64

If Byron was still in busyness today, they had all the advatages to be the biggest in our jet model jet industry.
Just too bad they passed away.. Great kits, even compared to some present kits..

G

Eagle Flyer

My Feedback: (84)

I would like to fire up my OS 91DF on a test stand. What would be recommended to do this? I am not set up to mount the shroud so using the DF setup won't work. Though I could modify it to do so I guess. A prop at those speeds, not safe I wouldn't think. ?????????

joeflyer

My Feedback: (48)

Eagle,
It is not recommended to run a DF engine on a test stand. Why would you want to do it?
It's not very safe and if you don't have the shroud and ducting in place you will not have adequate airflow past the head and can easily overheat. Wait until you have it mounted properly in the plane.

That looks like an early Mig with plywood wing spars in the photo. The early ones had a twist in the fuse that causes the plane to roll right. If you have one of these you can notice that the fin is not straight and the rear stab is not horizontal. You need about 1/8" of left aileron trim to get it to fly straight. In spite of that it flies great. Just be careful on your first flight until you get your trim adjusted. If it really bothers you you can make a former that fits inside the fin to straighten it out. That's what I ended up doing to mine. It really didn't make any difference in how it flew, but looked better.

Also you should reinforce the wing mounting and fuelproof the plywood formers. After about 130 flights one wing departed the fuse at full speed causing the Mig to go in.

Good luck,
Joe

Eagle Flyer

My Feedback: (84)

Your reasons for not running the engine is exactly what I thought. But I figured I would ask any way. Some times people have other good ideas I haven't thought of.
Yup, it's the early style. But my fin appears straight. And the stab will be when finished. I have the needed stuff to update the wing attachment. But I already reinforced the wing mounting in such a way I feel it should be sufficient. I may still remove the old silicone "glue" and fiberglass the fan/motor mount in. Good idea on fuel proofing it.

Thanks

reo

My Feedback: (130)

I'm not sure how others broke in the O.S. 91 VR-DF engines but I ground ran them mounted in the jet, running them reasonably rich for the first tankful or two and slowly leaning them out over the next few tankfuls...then off to the field. From what I have read over the years ABC engines are best broken in under operational conditions anyway.

Ron

joeflyer

My Feedback: (48)

Ron,
That's similar to how I have done all of mine. I would run them rich on the ground, just short of 4 cycling. Every 30 seconds I would lean it out slightly for 10 seconds, each time going slightly leaner. I'd repeat this until I could get a good repeatable idle. That usually took 2 or 3 tankfuls.

Then I would fly keeping it pretty rich. After each flight I would lean it out a little bit. By the tenth flight it would be business as usual.

Joe

Jackjet

My Feedback: (1)

Eagle Flyer,
you CAN run you OS.91 on a test stand with a prop - that is one of the best methods of running it in - use a 11/9 prop and do the rich/lean fuel line pinch when you do it. Just be careful and use a good quality prop and test stand. I have ran Rossi 105 -90-81's OS.91-65/s-K&B 100 - 7.5 -6.5 and too many others to count. Never had a problem doing it.

Jackjet