rmenke

My Feedback: (13)

Hi Jason Somes and Bob B:

On 9-30-05 Bob noted he was going to do a "Fit Up on the 90LX" for the Alley Cat. A little later Jason noted to Bob that they should get togeather on the telephone regarding proper engine for the AC from Jett Engineering. To this point, from Jason, it appears the Rossi 65 would be a decent aplication for the AC. I am a Jett fan, not a Rossi fan based on past experience, especially when it comes to support. After all the hype about the AC, I found one at RC Country and stuck it in the back of the Outback. Paperwork calls for a 50 to 60 powerplant. My SJ 50 fits right in, the 90L looks like it will fit with some grinding. Am concerned about the additional weight of the 90L VS 50, but see someone stuck a YS 110 in a AC which is truly heavy metal. My 50 has a home in the mail that must take place as a sneaker backup that I know will be good for 150+ and turn, and club rules legal. Now, this AC deserves the best shot I can give it as to engine. Am not opposed to adding another Jett to my existing lline up. Catch 22, its got to be a side exhaust. Other catch, my 90L will cost about 1/2 of a new 90LX, and is not even broken in yet! Charlie Rounder at RC Country showed me a new Jett 70 something that is a grunt engine in a 40 case. Don't think that will do the job, even with replaceing the muffler and abuseing the basic engineering design. The $64.00 question is which Jett side exhaust motor will give this airframe the highest speed coupled with decent flying and landing character. Stock AC landing gear is winmpy for a 90, but easially corrected. Charlie would not give me the AC without some mutual consideration. I must come up with a optimum 2 stroke install and then meet him at nutural territory. He will be YS 110 powered, other advantage, he is a good buddy of Dubs, not to mention giving away at least 40 years to him. Ok, so treachery will make up for the 40 years, but need a hand here fellas. What motor?

Cyclic Hardover

My Feedback: (3)

Concerns of weight? I shoved a OS 1.08 in the nose of a WM Midget. Works out fine. Other guys here have the Jett 90 in Lil Toni and Shoestrings. I'd go with it. Balance it out obviously and the wing loading may be higher but so what.

HaveBlue

Jett Engineering has a .76 if thats the one you mean , If I read the website site right , I'd go with the 90l(check out the weight on each) sounds like it wouldn't be such a bad option

MyWay

rmemke, How about a 23 oz. engine with muffler that will turn a 10/10 prop over 14000 rpm but is not a Jett engine?

rmenke

My Feedback: (13)

MYWAY:

Any engine that will turn a 10 X 10 14k is worth looking at. Any engine that will turn a 11X9 or 10 X 9 20k is more likable. Tell us please. Note, rear exhaust systems not a option here!

rmenke

My Feedback: (13)

CYCLIC HARDOVER:

You are rignt, the weight of the 90 would be ok, but would like a lighter engine. Must be flying electrics to much these days. Have had some real fast airframes that would simply snap out of a tight pylon turn, but ok when built lighter overall. Am trying to shoot for optimum here, do it once and be happy and fast and turn. You loose a lot of the fun when flying a challangeing airplane with quirks as apposed to a good gover that has no real bad habbits. Have a thing for turning inside the guy in front and play him out. Perfer being the doer, not done the to-r. Remember the old Caps. Great airplane until it snaps on landing, splatttttt. $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

MyWay

rmenke, Take a look at the Tower Hobbies .75.

bob27s

My Feedback: (19)

I have not seen the plane in person yet (other than Toledo for a few minutes). I think I had asked around to see if anyone had drawings/models of the aircraft front-end to do a CAD fit check. Nothing done to this extent yet.

A few folks are flying the AC with a YS 110 up front. The SJ-90L weighs about the same. CG should not be a problem. My main fit-check issue was the muffler installation

hooaa

My Feedback: (1)

Bob,
Have you ascertained what speed range the folks are achieving with the AC/YS110 combo straight and level? I'm presently using a YS110 in the Lil Toni and can only guess its in the 110-120 range. I'm hoping that the AC will be faster with the YS110 than with the Lil Toni. My only other hi rpm engines are a Jett 50 FIRE and a Nelson Q500, neither suitable for the AC. If the AC can get into the 135-140 range with the Jett SJ-90L then I guess I'll bite the bullet and step up.
Roland

bob27s

My Feedback: (19)

Ive not seen any solid radar or air-data speed numbers on the alley cat yet.

rmenke

My Feedback: (13)

MyWay:

Thanks for the heads up. The basic motor generates decent rpm. Looks like a good motor to buy and grind with. Say 3-.004 off the high port, clean up things and add a larger carb from the junk bin. The K & B screeamer 48 is one that really reacts to a simple hop up and pipe, about 22k with 8.75 X 8, not shabby for a cheepe.

twitcher

My Feedback: (3)

Got an A-Cat coming earlly next year. Still waiting for feed back on how the bird flies. It's only a model of a racer ....... not a racing model. I plan on using my Picco .67 marine engine in it. The head will be liquid cooled of course and can use up to 65% nitro if I desire. Got some prop testing to do on the engine stand. A 1 ounce capcity metal tank will supply the head coolent. Sure don't have to worry about burning down the engine. This engine was designed to run at fairly high RPM's (28K) so it won't be abused if I can get around 22k on a decent size prop.
If any of the tail feathers are "built-up" on this ARF, they will have to be replaced with something much more substantial. No one has commented about the ruggedness of the design. Will it take the massive power that you guys are talking about? Pylon turns at 135 mph (haha) ? Lots of strange forces going on at those speeds an a ARF! Will the wing covering hold up or blow into smitherines? AS you fast guys know....all fast planes have sheeted , glassed or composite wings for a reason.
At what RPM will a 10 inch dia prop go supersonic? Will the Jett 90 run at those RPM's?
Just a few questions I have and would like some response to them.

bob27s

My Feedback: (19)

The Jett 90LX turns a 10x10 prop up a bit over 16,000 (depending on where you are altitude wise).
With the long full size pipe, it can do a little bit better.

Bob

rmenke

My Feedback: (13)

Twitcher:

There are lots of open framed fast airplanes, the delta wings come to mind as a example such as the Shrike and Dust. I expect that with a good motor, they are doing 150 plus. Saw a vidio, camera was on a shrike. The wing covering was flapping near the center section apparently not ironed down well. Still kept togeather. Lots of Q-500 have foam-balsa wings that are well over 150 + and still stay togeather. The Alley Cat wing coverilng appears to be ultra coat which is stronger that mono-cote. Should not be a problem of flying off when ironed down well. The tail feathers appear to be solid balsa and does not rotate or flex to excess. Dont know if there is a stiffner inside or not. I don't expect this airframe with a 90 LX to run much faster than 150 at best. It will depend on the airfoil used. It appears about as thin as a Q-500 wing. Havilng had a Little Toni, Shoestring and Minnow from the Great planes line up, all dissapointing as to top end speed, I expect the AC will kick their buts hands down. The AC has a cleaner frontal area, smaller and thinner wings. I am not sold on the Jett 90 being the best engine for this airframe. There should be something in the 60 size out there that will turn in the 18-20K range and really make this thing scoot. Possibly a Rossi? Dont have any experience with the Rossi's, was given one last year to try, ran it on the bench twice and gave it back. Did not turn for poop, but dont know the intended design. The Sports Jett engines we are trying to make go fast are designed as sport engines. They have wonderful idle and spool up with authority, generally a outstanding sport engine. We are tryilng to make them do something they are not designed for. (Sports Jett). Their racing engines are another breed of cat that turn well over 22k with ease rich yet. Yea, I want it all, don't care how the engine idles. I have a older OPS that will turn well over 22K but it is a tank of a engine, and rear exhaust and carb. Am sure Jett could whip up something special for me in the 60 size, but just don't have the extra bucks to spend at this time. Will start flying the AC with my Jett 50 which sits right in with no mods needed and then take it from there as the guys find out what will make these suckers scoot. Bottom line, the design streingth appears up to any task you want to throw at it, with great motor expect 160-175 which is slow Q-500 times, but ideal for my needs. ENJOY

twitcher

My Feedback: (3)

rmenke.....
Thanks for the input. Am aware of the quickie construction ie foam/balsa, the open bay construction was what I was leading to. Guess we all saw some scary D Dust birds haul poontang at one time or another. Saw one literally blow up and that was pretty hairy. Stuff went every where .....didn't find to much of it either. Thats what gives me an un-easy feeling about subjecting an ARF (made in some unpronounceable island by people that haven't seen a real airplane fly) to high flight loads.
That A Cat is one trick looking bird though. Should be fun.
Merry Christmas