Jett 90 w/tuned pipe on a shrike 40?
02-06-2007, 08:19 AM
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Jett 90 w/tuned pipe on a shrike 40?
I am building it, but I am not sure if its really going to work. Anybody tried this or tips or suggestions. I plan to build in some mods to handle the extra stress. Anybody have an idea how fast it might go?
02-06-2007, 11:14 AM
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RE: Jett 90 w/tuned pipe on a shrike 40?
Ive never seen a Shrike 40 with any more than a FIRE-50 or 60LX on it.... those are darn fast enough 
Spars, firewall, fins ----- anthing you could think of reinforcing - you will have to do it. Id sheet the entire wing too.
Signficant engine weight increase over the 'small block' engines.
Other problem ----- keep in mind you will be burning a bit less than 2 oz per minute on fuel at full throttle.
Spars, firewall, fins ----- anthing you could think of reinforcing - you will have to do it. Id sheet the entire wing too.
Signficant engine weight increase over the 'small block' engines.
Other problem ----- keep in mind you will be burning a bit less than 2 oz per minute on fuel at full throttle.
02-06-2007, 01:28 PM
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RE: Jett 90 w/tuned pipe on a shrike 40?
RCMASTER:
Listen to CH here, very good advice for serious speed at a relative lower cost. If you want to stay with the smaller light engines, go with the Jett Q-500 or similar 40 that will give you 22K rpm plus as a standard. Like everything when you are talking speed, there are complications, trade offs and other limiting factors that all spell $$$$. The weight and rear carb of a vrdf engine does add some minor complications that you can need to consider in the project. Right off, you need to find some correct cf props that will hold up to the rpm's. Nothing like having a engine running 24k and spitting off a blade. If in the air, the engine and airframe are simply toast. If on the engine stand, the distruction of stand, engine and surrounds are scary. The prop at higher rpms will go supersonic at some point and must be tough to stand the stress. Recent posted pics on the rcu web site of jets going through the sound barrier give us a clue of the forces acting on the prop tip as it passes into supersonic speeds. If you are standing to the side of one of these things when they blow, I doubt if safety glasses will be much help. Weight becomes a factor to allso consider. The German speed guys seem to like the ops 61 which weighs in at a porkey 1.11.1 oz, the OS 91VRDF 1.13.0 vs jett 60 LX at 13.3 oz, weights just taken with the engines in the box and should be considered as approximates. Getting a DD to CG correctly with a OPS or OS will be a challange. With a Jett or Nelson up front, you can buy the prop over the counter and go scary fast at a relatively low cost. The guys in europe that hold the speed records build their engines, props and airframes and live for speed. Workmanship is outstanding!!!!!!!!!!! Do not ask one of their speed planes to turn left around a pylon, turning is not much of a consideration within their intended designs. Speed is a full time learning and experimentation studdy for most. Guys like myself who grab their foamy and go out to the back yard for some 3D practice and then once or twice a month, grab a racer and go out and try to go fast and turn left will seldom be a challange. There is just so much in our sport to ENJOY.
Listen to CH here, very good advice for serious speed at a relative lower cost. If you want to stay with the smaller light engines, go with the Jett Q-500 or similar 40 that will give you 22K rpm plus as a standard. Like everything when you are talking speed, there are complications, trade offs and other limiting factors that all spell $$$$. The weight and rear carb of a vrdf engine does add some minor complications that you can need to consider in the project. Right off, you need to find some correct cf props that will hold up to the rpm's. Nothing like having a engine running 24k and spitting off a blade. If in the air, the engine and airframe are simply toast. If on the engine stand, the distruction of stand, engine and surrounds are scary. The prop at higher rpms will go supersonic at some point and must be tough to stand the stress. Recent posted pics on the rcu web site of jets going through the sound barrier give us a clue of the forces acting on the prop tip as it passes into supersonic speeds. If you are standing to the side of one of these things when they blow, I doubt if safety glasses will be much help. Weight becomes a factor to allso consider. The German speed guys seem to like the ops 61 which weighs in at a porkey 1.11.1 oz, the OS 91VRDF 1.13.0 vs jett 60 LX at 13.3 oz, weights just taken with the engines in the box and should be considered as approximates. Getting a DD to CG correctly with a OPS or OS will be a challange. With a Jett or Nelson up front, you can buy the prop over the counter and go scary fast at a relatively low cost. The guys in europe that hold the speed records build their engines, props and airframes and live for speed. Workmanship is outstanding!!!!!!!!!!! Do not ask one of their speed planes to turn left around a pylon, turning is not much of a consideration within their intended designs. Speed is a full time learning and experimentation studdy for most. Guys like myself who grab their foamy and go out to the back yard for some 3D practice and then once or twice a month, grab a racer and go out and try to go fast and turn left will seldom be a challange. There is just so much in our sport to ENJOY.
02-06-2007, 02:17 PM
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RE: Jett 90 w/tuned pipe on a shrike 40?
I got the engine and pipe for free and thought the shrike would be easy, cheap, and stupid fast with that jett 90. Just something fun to play with, nothing real serious or expensive, although I am taking the construction serious as not to cause a danger hazard.
02-06-2007, 04:47 PM
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RE: Jett 90 w/tuned pipe on a shrike 40?
In that case, you would be better off digging up one of the older .61 size pattern ships and really having some fun with it Wing loading will be a bit more reasonable.
Take a look in the classic pattern forum for some ideas.
Or, since there is some re-design required anyway - perhaps scale up a Shrike - there is not too much to it, and build a "60" size version
Wing loading will be a bit more reasonable. Take a look in the classic pattern forum for some ideas.
Or, since there is some re-design required anyway - perhaps scale up a Shrike - there is not too much to it, and build a "60" size version
02-06-2007, 07:50 PM
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RE: Jett 90 w/tuned pipe on a shrike 40?
ORIGINAL: rcmaster-RCU
I got the engine and pipe for free and thought the shrike would be easy, cheap, and stupid fast with that jett 90. Just something fun to play with, nothing real serious or expensive, although I am taking the construction serious as not to cause a danger hazard.
I got the engine and pipe for free and thought the shrike would be easy, cheap, and stupid fast with that jett 90. Just something fun to play with, nothing real serious or expensive, although I am taking the construction serious as not to cause a danger hazard.
02-06-2007, 09:04 PM
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RE: Jett 90 w/tuned pipe on a shrike 40?
I don't know how this comment will go over but with these Shrikes or DD's, You could install a POS GMS and it will be impressive. Not that the engine is any great prize but the plane is. Why don't you try a cheapie and see if you like it. Then go for the gold.
02-06-2007, 10:18 PM
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RE: Jett 90 w/tuned pipe on a shrike 40?
I flew one of the Shrike .15-.20 size airframes with a nice .46 in it and it was smoking fast... but the owner/builder had to mod the ailerons due to flutter. I'd expect you'd have to do quite a few mods to the airframe to handle the stress and dynamics of speed with a .90. Please video 
02-06-2007, 10:28 PM
#16
RE: Jett 90 w/tuned pipe on a shrike 40?
Those ailerons that mount straight across like that are a flutter just waiting for enough
speed to happen. Tapering them out to the wingtips will help, shortening them will help
too as well as a barn door end at the wingtip.
FBD.
speed to happen. Tapering them out to the wingtips will help, shortening them will help
too as well as a barn door end at the wingtip.
FBD.
02-07-2007, 07:53 AM
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RE: Jett 90 w/tuned pipe on a shrike 40?
Flyboy Dave,
What do you mean by a barn door end by the wing tip? Do you mean like an offset balancer like on 3D aircrafts's rudder and elevator?
What do you mean by a barn door end by the wing tip? Do you mean like an offset balancer like on 3D aircrafts's rudder and elevator?
02-07-2007, 09:40 AM
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RE: Jett 90 w/tuned pipe on a shrike 40?
ORIGINAL: Mike Connor
I say go for it. Attached is a Shrike 40 set up for a 60 size engine. It is not my plane but the owner says it is fast and flies well. Move the firewall back along with everything else you can so it will balance. My Shrike has an 8 oz tank with plenty of room left over so a 10 oz should fit. I extended the hatch back so the batt. would go in the very rear of the plane. I think the Shrike 40 built per the instructions will work fine for strength if the builder is good. However the tail section could use a little beefing up. The two common complaints I have heard abut the Shrike is nose heavy and aileron flutter. You do not need the long ailerons so I would shorten them and do not over bevel while sanding. The leading edge of the aileron should be at least as thick as the trailing edge of the wing with tight linkage a must. A 9" to 10" prop with a lot of pitch should work. Those are my thoughts
ORIGINAL: rcmaster-RCU
I got the engine and pipe for free and thought the shrike would be easy, cheap, and stupid fast with that jett 90. Just something fun to play with, nothing real serious or expensive, although I am taking the construction serious as not to cause a danger hazard.
I got the engine and pipe for free and thought the shrike would be easy, cheap, and stupid fast with that jett 90. Just something fun to play with, nothing real serious or expensive, although I am taking the construction serious as not to cause a danger hazard.
As long as you use due care in building it .... it would be a lot of fun
The FIRE 90 loves the 10x10 size props, that would probably be the way to go there.This little plane (below) is still one of the favorite projects Ive seen folks build for the FIRE 90 size engine....
If I were going to to build something from scratch, just for sport-speed - id build something that looks sorta like this beast. Maybe try to cowl the engine in a bit more.... but for sport and looks - this is rather sporty looking.
02-08-2007, 12:17 PM
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RE: Jett 90 w/tuned pipe on a shrike 40?
ORIGINAL: rcmaster-RCU
Flyboy Dave,
What do you mean by a barn door end by the wing tip? Do you mean like an offset balancer like on 3D aircrafts's rudder and elevator?
Flyboy Dave,
What do you mean by a barn door end by the wing tip? Do you mean like an offset balancer like on 3D aircrafts's rudder and elevator?
02-08-2007, 12:27 PM
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RE: Jett 90 w/tuned pipe on a shrike 40?
ORIGINAL: bob27s
If I were going to to build something from scratch, just for sport-speed - id build something that looks sorta like this beast. Maybe try to cowl the engine in a bit more.... but for sport and looks - this is rather sporty looking.
If I were going to to build something from scratch, just for sport-speed - id build something that looks sorta like this beast. Maybe try to cowl the engine in a bit more.... but for sport and looks - this is rather sporty looking.
02-08-2007, 12:41 PM
#21
RE: Jett 90 w/tuned pipe on a shrike 40?
ORIGINAL: Troy-RCU
This is a barn door aileron looking from the top of the wing.
ORIGINAL: rcmaster-RCU
Flyboy Dave,
What do you mean by a barn door end by the wing tip? Do you mean like an offset balancer like on 3D aircrafts's rudder and elevator?
Flyboy Dave,
What do you mean by a barn door end by the wing tip? Do you mean like an offset balancer like on 3D aircrafts's rudder and elevator?
Mark
02-11-2007, 09:17 AM
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RE: Jett 90 w/tuned pipe on a shrike 40?
RCMaster, the Shrike will balance with the 90 with little or no lead, if you plan it out to start with. Put the battery in the wedge part at the very rear of the fuse, make a screw on hatch there. Shorten the nose by about an inch and reinforce firewall. Use plenty of glue and reinforce critical areas where it is practical and necessary, don't go crazy here. I would also round the aileron ends and thin them down some, might even give just a little more taper to the end to take care of and concern over flutter. Use spruce or popular wing spars, I use popular often, not enoug weith difference to worry over and they can easily be cut from stock you buy at Home Depot or Lowes on a table saw.You will be fine despite the skeptics here.
02-11-2007, 09:42 AM
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RE: Jett 90 w/tuned pipe on a shrike 40?
ORIGINAL: bob27s
This little plane (below) is still one of the favorite projects Ive seen folks build for the FIRE 90 size engine....
If I were going to to build something from scratch, just for sport-speed - id build something that looks sorta like this beast. Maybe try to cowl the engine in a bit more.... but for sport and looks - this is rather sporty looking.
This little plane (below) is still one of the favorite projects Ive seen folks build for the FIRE 90 size engine....
If I were going to to build something from scratch, just for sport-speed - id build something that looks sorta like this beast. Maybe try to cowl the engine in a bit more.... but for sport and looks - this is rather sporty looking.
