dubyabaker

I was advised to post this question in this forum regarding Jett Engines. I understand that they are pretty radical engines, but my secondary concern is their ability to idle at a respectable speed (such as an O.S. .40 size). One individual mentioned that the Sport Jett is the way to go for best idle speed, any ascending or descending opionions? Thank you.

Cyclic Hardover

My Feedback: (3)

I have a .50 and .90. You get what you pay for and i am a happy camper. Idles are extremely smooth.

HaveBlue

firstly I have no affiliation to Jett engineering!, I bought my first SJ, a 90l 1 year ago I now have 4 Jett engines, 2 90l's a 46 and a friend is bringing over a 60lx for me. I would happily replace every engine I have with a jett..unfortunately money doesnt permit with that being said.. I haven't had to many engines that start so easily (consistently) and that idle exceptionally well, perfect transition and above all a great top end...but remember they are a sports engine...the upper end of that classification and I cant see how anyone could be dissapointedwith a jett ....but this is only my opinion.. I am sure a few more will chime in here with their thoughts


cheers
Roger

ChuckL

My Feedback: (2)

My jetts all Idle great and will go from idle to wide open in a split second with no hesitation, they are worth every penny. Great support and parts availability also

rmenke

My Feedback: (13)

dubyabaker:

You are into a group of very experienced people for the most part that know their stuff. I do not make that claim, but I have been playing with engines since the late 1940s. Yea, thats a long time. Started out U control and held a world speed record shared with a buddy in 1949. Have had a few engines since that time. Do I have Jetts? Oh yea, a 35, 50 and 90l. Every engine has its own personality. What they have in common is easy start up, outstanding idle to a fault, unbelieveable throttle response and good top end. Note that these are designed by jett to be SPORTS engines, not race engines. They work at the top end of all others out there, simply the best. Too expensive many say. Same guy just plurchassed YS 140 for $475. with out a blink, or OS, or Sato just cause they sounded good. You get what you pay for with the Sports Jett engines. Try one soon as you will be loosing out in the intrum. My favorite? My little SJ BSE 35. Thing thinks its a 46 and will outrun and outpull most everything out there. I interchange props with my 50 once in a while. Hope Bob or Dub does not see that! The little guy is one of those that has a attutidue and lets you know it right off. Everyone in the club knows when it cranks up, its growl is unique, not like say a Webra 35 or Irving 39. Setting the needle is the so easy and simple. She lets you know when you are lean, and also happy. To date, she has gone through 3 seasons in a little home brew club racer, and actually lost one or two races from a stupid needle setting, blowing the start buy a whole bunch or some other dumb thing. The guys hate it with a pashon cause it just keeps on getting stronger every year. She failed to start once. The carb fell out during starting. My fault obviously, but the motor had just won the last heat in this state> Yea, Ido love my Jetts and will have more when finances permit.

crasharama

Hi dubyabaker,

Yep I have one of Dubb's SJ50's as well. From the moment it arrived over here I knew it was quality. I had never seen one before that but took a chance as everyone here loves them, & now I am a convert too.

There is a couple of them at my club now, one guy is using a BSE 35 in an old timer, has the most crazy vertical performance you will ever see, out of sight in under 30 seconds

Mine has a very consistant idle, as tame as my TT61, incredible transition, better than nearly all others, & a really strong top end. Like so many have said before me you get what you pay for.

When I get up a couple of classes from where I am going to be running in this years pylon rounds, there will be a couple of the Jetts here with the black exhausts & venturi's too.....

Tony.

osborjr

My Feedback: (19)

Well here is my question, I just bought the 90L for a Cermark F-16, I have had 90 engines before and usually ran 15x6 or 15x8's on them, I am confussed with running a 12x6 on it. I mean I usually run a 12x6 on a 60 engine! Of course I know you are not going to get enough ground clearance for a 15" prop on the F-16. Someone help me out with this.

funflyerf4

My Feedback: (6)

All I can say is what a combo The cermark f-16 and the jett 90. I have the same set up I am running an 11-7 at 15,000 to 15,200 rpms. Over 100 flights to date and never a engine problem. I will be ordering another 90 for a V mar f-4 next week.

Crazy4Flight

My Feedback: (540)

They ALL run great, a few of mine like to be real "wet" when starting. But that is true for the OS.25FX and OS.32SX I have!

A got a SS40 single needle Carb in a trade from a pylon racer. James Rebuilt the old gal and she kicks royal butt in my SIB Kobra.

Just ordered a .60LX for one of my Whips Why? For a even BIGGER GRIN!

On that big auction site I am known as Jettfreak58

Bob Brother # 104 or 105


Jett sport 50 UK Magnum
Jett sport 50 ACM Whiplash
Jett FIRE 50 ACM Whiplash
Jett SS.40 SIG Kobra
Jett 1.20 G.P. F-4
Jett sport 50 being fitted to a Wild Hare LR_1

Rebellion

My Feedback: (2)

Well, I'll throw in my tiny bit of Jett experience here. This past fall, I bought a Sport Jett 50 with the racing muffler. It has only been run on the bench so far, since it's intend home is not yet complete. The engine is truly amazing. Throttle response is incredible. Kinda neat is a very brief puff of blue smoke as it hits the pipe just under 18K rpm. After about 15 min. of break in, I had it idling as low as 2,600rpm. That was with a pylon prop cut down to 7.75 x 8.75 and without touching the idle adjustment at all. It did respond a bit better from a 2,800rpm idle though. Even as radical for a sport engine as this is, it was very easy to handle. Not touchy on the high speed needle at all. With just this brief encounter, it's going to be difficult for me to be happy with anything else.

Cyclic Hardover

My Feedback: (3)

You ought to try bumping up that prop to the apc 11/10 or 11/11

Bob.R

My Feedback: (2)

With a little care, the Jetts will last a long time, which offsets the initial cost. I've got a 10 year old SJ 46 still running strong. Use a little after run oil and avoid lean runs and you can enjoy a Jett motor for many flights.

rmenke

My Feedback: (13)

Cyclic hardover:
What sized jett is in the ultra sport and what size is the ultra sport. Just purchased the 60 size from e-bay with the intent of taking two bays off each wing, a few inches off the lingth and as much hight as possible, retract and run. A super sportster streemlined and chopped at the wing is one of the fastest airframes in our club, and has been one of the planes to beat for years, with a Super tiger 40 and then 50 yet! The swept wing and streemlinning of the Ultra sport should give more? Also got a 40 sized, but it is the latest addition, thicker wings I think, so went to the old 60. Did have a 40 sized years ago, and it was fast stock with fixed gear.

Cyclic Hardover

My Feedback: (3)

So much for my "grafixs?" I run a Jett 90 and it is the 60 size. It is a very solid flyer. It's different from any other plane i have or seen. its like the way it moves through the air, if it ever hit something, it would go through it like a freight train instead of coming apart.
I have seen many .40 size fly and this is nothing like it.

I don't thnk you would want to fly it like a .40 size zipping around cutting corners and such. It handles different like I said. Sort of flys like a high speed B-52. I have spring air retract in the wing. Very fast set up. Taking a few inches off the wing will be good.

I would not mess with the length. Another thng here is that as far as fast goes, it will be a "top end " mover. Their may be others in your club that can take it off the line. but won't touch it on the other end. Also using a 12/7 apc

MJD

My Feedback: (1)

If you run a Jett .90 forget about running those 15" lawnmower blades on them - those props are good for a low moving sport models which need lots of thrust at low airspeeds. Moderate/Low rpm, low pitch, large diameter = higher static and low airspeed thrust, but low ultimate airspeed. Except for specific models, most Jett engines will do their magic on lighter prop loads than you may be accustomed to with lesser sport engines. Don't be afraid of the suggestion to run a 12-6 on it - it may sound like a small prop, but in reality a 12-6 is a fairly high load for a .60 and a moderate load for a .90. It's not extreme, just not what you are used to. You are not even remotely close to underpropping the engine on it. Think of it as a really hot .60, not a .90, and your instincts will serve you well. Don't get swallowed up in the torque versus horsepower debacle either - there is a festering cesspool of misinformation bandied about on that subject, including by "respected' journalists on engine matters. Unless you want your F-16 to fly like a dog, run a smaller and higher pitch prop on it and keep that engine up in the recommended rpm range. Horsepower makes airplanes fly/climb fast, not torque. Just use it well. Torque is one part of an equation that requires two major variables. RPM is the other.

I suggest you write bob27s on the Jett direct support forum for specifics, as suggested earlier I think. He knows what he's talking about, and can likely give you very specific recommendations for this aircraft/engine setup.

Jett SS engines are NOT radical in their manners or setup. They ARE radical in that they are top quality engines that not only provide excellent operating manners, but exceptional performance, wide speed range and great throttle response. You get EXACTLY what you pay for. Better, faster, cheaper - pick two, all three not possible in one product. In this case you get the first two but you have to pay an appropriate amount of money for it. They're not that expensive, just more than the run of the mill stuff.

MJD

MJD

My Feedback: (1)

Typos, typos..

- those props are good for a low moving sport models which need lots of thrust at low airspeeds.

=

- those props are good for slow moving sport models which need lots of thrust at low airspeeds.

osborjr

My Feedback: (19)

Thanks MJD, that makes a lot of since,
Jerry

bob27s

My Feedback: (19)

Looks like yall got this covered pretty well Thanks folks.

Sport-Jett engines are just that ----- sport engines. They start, idle, transition as well or better than most engines, and have top end power superior to just about all engines in their size range. The SJ-90L is a "60" case engine. Use it where you would normally run a high-output .61 engine. The prop sizes are not a mistake. If you want to turn a 15" prop, The Jett 100L or 120L are designed/tuned for lower rpm, bigger props (same size and mounting as the 90L).

Any questions.... Im usually here

Bob

AllanU

Great info here.

What is the difference between the Super Sport 40 (SS40) and the Sport Jett 40. Can the carb on the SS40 be changed to have the idle characteristics of the Sport Jett 40 but still have more power and RPM than the Sport Jett 40 RPM?

If I wanted to order a Super Sport 40 that had good idle, what would I Order for options?

Al

bob27s

My Feedback: (19)

The SS.40 engine is basically designed for club and regional racing rules. Has limited idle capability (because of the rules it was originally designed for), and incorporates a slightly shorter muffler (the SS muffler). The SS carb can not be modified or changed to the two needle configuration - you would have to purchase a red-jett sport carb.

The SS carb only provides 200-400 more rpm on the top end anyway.

For general speed/sport use (if you are not racing under rules requiring an actual .40 cid engine), and using the engine on a fast airframe (Q-500, dust, shrike, etc) your choice would be either a SJ-46, SJ-50 or SJ-60L combined with the SS muffler. Any of these provides performance equal to or exceeding the SS40 engine, and all have full throttle and idle capability (one of the best carbs in the business). The SJ-40 is available, but we rarely sell them.

Bob

Meschmidt

My Feedback: (15)

My nine year old SJ 46 still running better with age. Only had bearings replaced and carb update couple of years ago. Puts a smile on Dub's face when he sees one of his old designs. Paul

Crazy4Flight

My Feedback: (540)

I ordered a 60LX FIRE too add to my collection

huey-pilot

My Feedback: (17)

I have a 60LX Fire on my Diamond dust, very fast. Over 20,000 rpm on the ground with an APC 8.8x8.5 propeller and over 19,500 with the APC 8.8x9

Crazy4Flight

My Feedback: (540)

I have yet to build a plane for my new JETT

A Haslam Wild Wiz kit arrived the other day.