maverick

My Feedback: (12)

I have just bought a Sig Kobra brand new built airframe with no engine and was considering putting an OS .32SX on the front. But I am after speed and have heard these planes are rather quick, so I am now thinking of putting a Jett BSE .35 on it.

What do you guys think?

I needed something fast to get in the air quickly whilst I build my Patriot for the Jett .50 so that is why I just picked up the Kobra.

Any thoughts on this combination and the Jett BSE .35 in particular?

ChuckAuger

My Feedback: (12)

I had one with a OS40VF w/pipe, and it was right quick.

tomr-RCU

I'd go with the .32,

Weight is very important with this plane. Mine has a Norvel Big Mig 25. Total weight is exactly 3 pounds. It is very vast, be carefull with the rudder linkage. As designed because of the control linkage to the rudder it starts to flutter when you get much over 100mph. I went to a plastic tube in tube type control and this ended my high speed flutter.

Tom

maverick

My Feedback: (12)

Well from my research I have found that the OS .32SX weighs 12.32 oz with muffler and the Jett BSE .35 weighs 11.6 oz and this weight includes a spinner nut and muffler.

Looks like the Jett is lighter than the 32SX especially when on the 32SX I would have to add the weight of a tuned pipe setup.

Anybody else have any feedback on this?

ChuckAuger

My Feedback: (12)

I'm not gonna dispute tomr..I don't know what a 40VF weighs..my servos were mounted behind the wing saddle in the fuse (except aileron) and it landed like a trainer.

Kinda like your hypothetical Patriot OS ve Jett thread..pretty much anyting will work, just depends on how fast is fast enough. I cant find a pic of mine, but here is a Hammer 20 with the same engine/pipe/gear as was in the Kobra:

pdxpaul

My Feedback: (1)

This thread feels like deja vu on this OS v. Jett debate.

I had Kobra with 46fx, TT46 on a pipe and then a Jett 50. With the FX and Jett, it was too heavy. My favorite was the TT46/pipe. It was a nimble rocket. I remember taxing it out the center runway, stopping, slamming the throttle to full, and the thing was headed to the horizon with a victory roll take off, faster than you could say, that TT really likes that pipe.

I also thought the plane was somewhat limited in the speed department by the relatively thick wing. However, it is very good flyer.

If you choose the OS, get a Performance Specialties pipe.

Paul

maverick

My Feedback: (12)

I guess you are right! I wasn't thinking that way when I posted the questions as I have no knowledge of the Jett BSE engines so thought I would ask.

Anyway I guess the question has been beaten to death in the other thread so please disregard this. I have decided on the Jett 50 for the Patriot, so for the reasons I chose that, I guess the Jett BSE 35 is the answer.

Sorry for wasting your time.

pdxpaul

My Feedback: (1)

No waste of my time. I enjoy reading this stuff.

To further perpetuate your decision, the OS 32 is no slouch of a motor, provided that you put a pipe on it. There was an OS 32 with a PS pipe, at my field on a 20-size pylon racer that was clocked in the 130's. It had no problem turning 18k, but I don't remember the prop. On the other hand, if money is no object, Dub's motors are the best.

Paul

Razor-RCU

My Feedback: (50)

This is not wasting anyones time!! I also love reading about all this...

With 500,000 posts or whatever it is, every question has been recycled. Sometimes I find an old thread and try to bring it back to life, simply because I like these types of topics!

Keep it up, or I will die of boredom!!

BTW- What does it feel like to consider performance without worrying about the pocketbook?

The YS-45 is the best I can afford, let us know what you decide and how it works....

james

maverick

My Feedback: (12)

OT - This is not entirely true!

I do run an extremely tight budget in my household, but one of the keys is that both my wife and I get an allowance each month that we can spend on whatever we want without either of us having to justify it. BTW my 2 kids get an allowance too, but less than my wife and I get. They have to budget their own spending and cannot dip into the remainder either.

This way we aren't tempted to dip into savings and we don't have to try to convince the other that what we are buying is 'worth it'. We do use a credit card to make online purchases but we won't purchase anything for ourselves if we don't have any of our allowance left. I will not purchase anything that I could not pay cash for. (Houses and cars excepted!)

One thing I have learned though is that if I am going to buy something I will research it almost to death first and then go out and buy whatever is the best item in that field. I would rather pay more up front but only have to buy it once.

And for the record there are a lot of things I would like to buy that I can't and/or won't because of the cost and because it would come out of my allowance. It sure makes you get your priorities straight and only spend on items you really want/need.

I don't spend any money on coffee, cigarettes, gambling, soda, junk food etc. and I save it for my one hobby.

I work with a guy who goes to Starbucks on a regular basis and buys one of those huge coffees about 5 times per day. So he is spending about $15 per day or about $325 per month just on coffee. I see this as a waste but he doesn't.

Now you could easily buy a Jett engine with the money he spends on coffee and most of it ends up straight down the toilet! Your body does not need coffee. Water is free and that is what your body needs. It still amazes me how much coffee and soda people consume.

It is all about priorities. One last point whilst I am off topic. The golden rule of budgeting is to pay yourself first. By this I mean take a percentage (try 10% - We do about 22% but have extremely high goals of early retirement!) of you monthly salary and move it into an account where you can't touch it. Do this before you spend any money or pay any bills. Then live off the remainder. If the remainder isn't enough then lower your expenses, do not touch your savings.

By regularly paying yourself and using the rule of compounding interest you will be amazed at how it grows.

Now back 'on topic'!

What is the advantage of the Bar Stock Engines over the standard castings?

ckoerner

My Feedback: (2)

I have an OS .32SX on my .15 size shrike. It has a Macs tuned pipe. It screams. It sounds great when it comes on the pipe. It is a little loud if you have noise restrictions at your field. Always starts on the first flip. I don't think you would be disappointed. I haven't had any experiences with the Jett. I plan on using the Jett 50 on my Whiplash though.
Later,
Craig
Craig's Shrike

Mike Connor

My Feedback: (5)

You may want to check the Jett site again. The 11.6 oz is WITH OUT a muffler.

tomr-RCU

Norvell .25 is 8 oz with muffler, and has start and stop verticle performance with the Kobra, it is also inexpensive.

I've flown heavy kobra's and they just wern't the same. The one I flew with a old 40 ball bearing engine (and custom reinforcments to other stuff) came in at around 4 pounds. Mine came in about 3 pounds. So had a virtually the same power to weight ratio than the heavier plane with more engine. The little norvell at about .85hp in a 3# Kobra has 3.5 #/hp ratio. At 4#'s the Kobra with a 1.2 hp .46 has a similar 3.33 #/hp ratio So with the .25 you have virtually the same power with 25% weight reduction.

The small 44" span plane flies like it's on a string when kept light, 4 point rolls and knife edge are simple, add a bunch of weight and it stay's fast but isn't near as good a flyer. It becomes limited to rolls, loops and high speed passes. Kept light with a strong engine and it's like flying a mini pattern ship on steroids.

It is definately one of my favorite planes, but it pays to keep it light. My next one is going to get the TT36 with a light mousse can muffler. I'll gain about 4 oz (still light) but get a 33% power boost.

Tom

maverick

My Feedback: (12)

You're right! I read it quickly and the saw the part where it says 'add muffler' as being 'and muffler'.

So it is going to be even heavier than I thought. Maybe for this bird the OS 32SX would be better.

maverick

My Feedback: (12)

Does Macs make a pre-tuned pipe for the 32SX or do you have to experiment to get the right size?

ckoerner

My Feedback: (2)

I cut the header at where they say to start and have left it there. It comes on the pipe pretty well. Of course with diff. fuel and props, you will have to adjust. It is a loud set up. They do make a quiet tuned pipe. I can measure where I cut it if you decide to go this route for a starting point.
MACS header part#2340
MACS tuned pipe part#1120 (1.2oz)
MACS quiet tuned pipe #1020 (2.4oz)
Later,
Craig

Razor-RCU

My Feedback: (50)

Mav,

Well put... You know I was kidding about the $$ right?

I do the same thing as for budgeting, I am getting married in 3 mos. and I can only use my work bonus, or football pool money for R/C stuff! ( thats not much I'm afraid...)

For some reason I would wear socks with holes in them because they are just not "necessary", but will buy a $5 dollar glow plug!

Hope all is well,
james

smokinT

My Feedback: (6)

I have had several Kobras, a Kougar and a King Kobra. The fastest Kobra was with a Webra .32 on an open pipe. Incredible vertical but would flutter on the horizontal. If I did it again I would put a metal-gear mini on each aileron and ditch the torque rod. Also, would try decraesing elev/rudder area. You can not get around the planes very thick airfoil, however. Kept light, a great little stunt plane but will never be a true hot-rod due to that wing.

T

pdxpaul

My Feedback: (1)

T,

I thought of finding someone to cut foam cores for a second, thinner wing for my Kobra. Decided it was more trouble than it was worth, because of the work needed to the wing saddle on a finished model.

If I was building a new kit, I would certainly cut down the rib height and shorten the ailerons. Full strip ailerons are not good for speed, and were the source of my flutter problems The Kobra has a lot of potential with its sleak looks.

Paul

maverick

My Feedback: (12)

Yeah, I know!

Flyboy Dave

My Feedback: (21)

....laying around, and wanted to go fast....WHAT !!!
A K&B .40 Q-500 ? Never mind....just kidding


Dave.

da king

My Feedback: (5)

Well a couple of years ago i had a kobra. I built it with the t-38 rudder. At the time i was flying .30 helis. I tryed an irvin .36 and a os .32sx. Well it was pretty fast with both but nothing to right home about. I had a heli max pipe for my heli laying around and some 30% cool power. Yes i put it in to see what would happen.

Well i wasnt ready for what i did and it was out of this world. Knife edge was hands off. If you believe that. The thing was on rails. By far the fastest plane i ever owned. The best part was when i mangend to get it slowed down ( took a few trys ) it would fly so slow that i would lose control from lack of air over the surfaces.

Motor .32sx....30% cool power fuel.....apc 9x6 or 8x7 i think.....macs header with heli max pipe for concept heli. If i remeber it was 3lbs or slitly under.

I also had two ailron servos in it. No flutter.
Hope this helps

ajcoholic

My Feedback: (10)

Yeah, I did the same thing when I took my mini pipe and engine out of my concept 30 and put it into a plane.

I dont think a lot of airplane only guys consider using the mini pipes sold for helis.

I want to try my CVEC someday, as when I put that pipe on my OS 32SX, Ihad to go up 30mm in blade length to keep the head speed under 2000 rpm! On a plane, I can see it being a wicked combo.

I had posted a thread a few months ago to see if anyone was using a CVEC pipe on a plane and didnt get one reply... If you dont know what a CVEC pipe is, its a special mini pipe that has a patented sprung variable exhaust. I dont know the physics behind it, but it sure adds the power and is NON rpm selective, ie, you get the boost throughout the entire rpm range as well as an improved idle. Once again, that is what we experience in the heli's, havent tried it yet in an aircraft installation...

AJC

ajcoholic

My Feedback: (10)

BUT... if I had the dosh inmy pocket, Id go with the JETT. Cant go wrong there!

Also, the BSE engines are the same internals, just a stiffer, stronger case. I like them, but the investment cast cases are allready pretty beefy and look sweet also. Better get one of each Maverick!

AJC

maverick

My Feedback: (12)

You paying?