Sport Jett .46 vs OS .46FX?
 

I have been looking at the Jett engines to put on the front of a GP Patriot that I am about to start building. I have heard good things about the Jett engines and how powerful they are.

Well I went to the Jett Engineering website to look at the specs. of the 46 and found the following:

Displacement: .46 cu.in.
Weight: 16.75oz
Prop: 10x6
RPM: 16,500
Price: $235.00

What I am interested in is doing a comparison with the OS .46FX which I currently run on a World Models T-34.

On the T-34 turning an APC 9.5x7 prop I am getting over 16,000 RPM. Also the OS wesite lists the weight of the 46FX as 16.45oz.

So the real question is why would I spend more than double the money to get a Jett .46 and on a prop with slightly less load factor only get a few hundred more RPM and it weighs slightly more too?

Why do I keep hearing Jett engines have significantly more power? Have I mis-interpreted the specs. in any way? What else do they have going for them?

This is not a bash in any way, I am just trying to understand the benefits of going with Jett.

os 46 fx
 

This has been discussed here often. Final answer has always been its hard to beat the os for the price. It will get you close to 150mph. If thats good enough then your done. My concern has been durability. The jett has a bigger crank, bigger bearing, and harder piston/cylinder. But the guys from LA claim they fly their os weekly at top rpms and it still runs good as new. If you want to go faster the jetts will hold up better and turn more rpms.

Sport Jett .46 vs OS .46FX?
 

I am "Mr Tell it like it is." I have the DC F20. With my close friends we have a total of about 10 of these planes and the Patriot. They all run either YS .45 or Jett.50's with 9/7 apc props.
*A couple of "outsiders" also have the DC F-20 and they run OS46fx. Now the 46 fx is a great engine. I have a couple and no complaints.
* Thing is although they run good on their planes they do not run fast. They just poop around the sky. I have never seen a Jett.46 perform, only the Jett.50 and .90 which I have both also. Since the Jett.50 is only $25more than the Jett.46 it would be silly not to buy it. One is a gamble but the other is a sure thing.
* With the amount of time and effort you will put into this plane with retracts an all, you may ought to stay away from "Kmart."
With a Jett .50 it is guarunteed you will get a least 130plus mph rountinely.

engine comparision
 

do you know what prop they are running? do you know if they want to go fast? Not everyone wants all out speed. Without knowing what weight,prop, muffler, pipe people are using it is not very helpful to say this engine is better than another. I have the 46fx on a trainer for the kids. I want it to run slow but have alot of thrust. I run an 11x5 on it. It flies great for them. From all the data posted here you cant beat an os 46fx for 90 bucks. If you have more data to share it would be appreciated.

Sport Jett .46 vs OS .46FX?
 

Maverick,

I hope this will shed some light regarding the Jett engines...

First: Buying a Jett engine is like buying a warranty with the piece of mind. One that can always guarantee you Quality, Reliablity, Power and Longevity.

Second: When I mean Quality... I mean REAL Quality. Not one that make certain claimed based on the optismitic side.

Third: The Reliabilty of a Jett engine is second to none. They're very solidly reliable and can dish out what ever you put it through year after year without any fuss or tinkering. This I can not really explain it to you. The only way to understand it is to own one (I own many's). :)

Fourth: Power is something a Jett is/are known for and anyone who has owned a Jett engine's would know. When Dub Jett advertised his engine with those rpm, they're are the Guaranteed/REAL rpm that you would expect from that particular engine. Dub usually make less claim than what his engine's will do in the real world to make certain that it meet or exceed the advertisemend. When you get one of his engine, you will see more rpm than what his advertisemend showed. This I can attest it to you because I have many of his engines and can tell you from my personal experience. My engines usually get 500-800 more than his advertisemend, and one of my BSE Quickie Racing engine, I get as much as 1000 rpm more which surprised me (Dub claimed 19,000 rpm on the ground and I got 20,100... maybe because it was a hot that day). You can not say that about others manufacturers as they tend to make their claimed on the optismistic side.

Fifth: And last, but not least... Longevity can only be obtain with good, high quality material used with the highest manufacture quality control. In this case with Jett engines, they are hand match and hand fit/assembled and test run to make sure it meet his advertisement. With all these, you can assure you will get what you've paid for it, period.

One other thing... Many people will make claimed that their engine's not too far of a Jett engine and why should they pay more and only get a little more for it. Well, in reality is... they have never own one to compare them side by side, test them on the ground and in the air, day after day and year after years... without it, they will never find out what is truely is to be Jett powered. :D

I've owned many engine brands out there, but none meet my expectation other than a Jett to say the least. ;)
Also, something you and everyone else should know... Dub Jett could get a lot more power out of his engines, but he choose not to and to keep it at that and make the engines more user friendly than they've already are for the Sport fliers. This is the coversation I had with Dub at the Phoenix JR Gold Cup Quarter Midget .40 Race last February 2002.

It is a piece of mind, indeed!

Sam

Sport Jett .46 vs OS .46FX?
 

Remember to keep focused here. I have a 46fx on a Shrike and I am pulling around 125ish. Thing is the plane only weighs about 3.5lbs. 46fx on a 7lb F-20 or Patriot is a fantasy. If you want a jet to perform like a jet, get a Jett :D If you want the jet to fly marginal, then the 46fx is yur engine. You said not everyone wants all out speed. Then why buy the Patriot. If this is the case, why consider the Jett in the first place and throw a Tower 46 on it. and save a couple hundred bucks.

Sport Jett .46 vs OS .46FX?
 

Well I do have a 46FX on a World Models T-34 using an APC 9.5x7 prop turning 16,000rpm and it just isn't fast enough for me. I am trying to move up to jets and need to get more experience with flying fast planes. I had a Weston Magnum that bought it on the first flight last weekend and am looking for something to replace this. From my calculations (not radar confirmed) I think the T-34 is doing around 90mph. So I am looking for the Patriot to be doing somewhere around 130 - 150mph. I want it to do it all day long, have a great idle and transition and not be too difficult to setup and tune. Price is not really an issue. It is sounding more and more like the Jett 50 is probably the way to go.

So what speed would a Patriot with retracts, running a Jett 50 with an APC 9.5x7 prop using PowerMaster YS20/20 fuel do?

more speed
 

how about changing the prop on the plane you have and see what happens. easy and cheap. the 46fx should turn a 9x9 about the same rpms. takeoffs and vertical will suffer but top end should improve quite a bit. You cant have it all. A light plane with lots of thrust and high top end speed would be nice but you have to give up one to get the others.

Sport Jett .46 vs OS .46FX?
 

Maverick,

I can not really say about the speed of the Patriot (I don't know of that plane and don't fly Sport plane... for now), but I know a Jett .50 with a competitive Quickie 500 kit would easily exceed 150+ mph with proper racing prop.

As for the Patriot, it really depend on the weight of the airplane and airfoil design and how clean it is. If the plane is clean and the weight is around 5 1/2 lb. or less, I would recommend you running an APC 9x8 D-1 Hub Racing Prop (not Sport APC 9x8 prop) which have a very narrow blade at the tip and it should get you about the 130+ mph in my quesstimation. If it's lighter, probably more...

Regarding your OS .46FX... don't waste your money on the APC 9x9. The engine will NOT be able to pull that kind of prop around 16,000 rpm as mentioned ealier. You're lucky if you can get a good needle on an overloaded engine. Best prop for the OS .46FX would be a 9x7 to 7.5 pitch. Hope this help.

Sam

prop load
 

#1)going from a 9.5x7 to a 9x9 is only a 3% increase in prop load
#2)that data is from a real engine.
#3)dont present as fact what you guesstimate to be the truth.

Sport Jett .46 vs OS .46FX?
 

So what is an example of a good Quickie 500 kit?

I wasn't going to try this. The prop I am running now is the one recommended by all of the T-34 racers out here in California. There is a racing series for this plane and they all say that after extensive testing the best prop for the 46FX on the T-34 is the APC 9.5x7 pylon prop.

best prop
 

When you say you want the best prop in one sentence and more speed in another these are two different things. You need to decide what it is you want.

Re: best prop
 

OK. More speed!

But I would think racers would also be after more speed, so therefore the prop they recommended would be the one to produce that.

Sport Jett .46 vs OS .46FX?
 

Don't even think about trying to Run a APC 9x9 on an .46fx.

Not only will you not hit 16,000 rpms, but you'll be lucky to get the thing to needle at all.

Although it doesn't look like much more prop than a 9 1/2" x 7. The 9 1/2" x 7 is a Narrow blade, and does not put nearly the load on an engine as a 9x9 sport prop.

To be honest, I think a Sport 9x7 prop is too big for the .46fx.


Maverick,

You asked about a good Q500 kit, their are several depending on what you want to do with it. If you want a basic kit, you can buy one from Bill Vargas (His Racer II). Another option may be the Lanier Predator ARF. The arf will need a little modifications to handle a Jett .46, but the Arf is only $120. If you wanted to fly it with an O.S. .46 FX you would have no problems hitting 110-120 mph with minor work.

Sport Jett .46 vs OS .46FX?
 

Now we are talking about several engines here and all the brands brought up are excellent running engines and like i said earlier, I have some of them to include the "Jetts. But as nice as some are they may not be the right engine for what your looking for.
*Now that we finally know what you really want and it is speed then go with the Jett.50. If you purchase this engine you will get what you want. I get 125mphwith this setup but this is great considering I am t 5000ft. Those with identical combinations at seal level are getting around 150mph.
*One thing the Jett has which is unsurpassed with any other engine is compression. I have seen this first hand. The compression is so high it seems as if the cylinder has "ceased". It is one tight mother!
* Two ways of breaking it in. On a stand orrrrrrrrr-- if you decide to make your first runs onthe plane, use a chicken stick. Reason is due to the compression, I saw a guy make his first start up on his F-18 with a Jett.90. He put the starter on the cone, cranked it and engine,muffler, firewall and the whole front end flew right off the plane and he had it glassed which you need to do even for the .50
* Now why the Jett over an MVVS or Rossi? Customer Service. If you want a nightmare, then go the other route. You buy direct from Jett and if something goes wrong or you need advice, you deal direct with Jett-no middle man. Sometimes the extra cash is worth it in the long run.
*When ever I send Jett and email, they answer it back within a day. I have no complaints

Take care.

Sport Jett .46 vs OS .46FX?
 

OK. So it is looking like I am going to go with a Jett 50 but what is the idle and transition like?

I don't want something that has to be run constantly wide open. It needs to have a good reliable idle, excellent transition, be bale to run at any throttle setting and be easy to setup and tune.

Does this describe the Jett 50?

I would trade some of the top end speed for the above qualities.

Sport Jett .46 vs OS .46FX?
 

Yes-- but idle and transition depends on how good you can dial it in. I promise you with this engine on this plane and a 9/7 or 9/8apc, you will have your hands full. You may also want to consider Kavan wheels.
*They are made of a hard plastic and they enable you to slide the plane sideways without wheel hop when the end up the runway comes up to fast. I have them on all my planes to include the big mustangs.
In a way it is kind of funny, usually the more powerful engines are a maintenance nightmare but this so user friendly its scary. Nothing difficult about it. Looks and adjust like any other basic 46engine.
You go through all the engine stuff around here and there is controversy on them all except the Jett brand.

Red Jett carb.
 

You bet it does. Slow idle, excellent transition and will run at any RPM. There is a little bump when it jumps on the pipe but that comes with any engine with a pipe or tuned muffler. I have hundreds of flights with a Sport Jett 46 and 50.

46 fx
 

#1)OS46FX with Macs muffled pipe and header
15% Omega
APC 9X9
15000RPM
about 500 feet above sea level

#2)Os 46 Fx (post # 1)

Homebrew 6%, 18% aerosave, stock muffler w. deflector, modified 12,25x3,75 apc = 14200rpm.

#3)Tower .46BB 11x4 MA 16.2K Tuned Pipe 15%N, 21% (80/20)

#4)Magnum XLS 40A ABC 11x4 MA 15.6K tower muffler 15%N, 22%

These are actual data. The prop loads are all about the same. The jetts are better but not by as much as you would like to think.

Sport Jett .46 vs OS .46FX?
 

Stay with the Jett, Everything else is a coin toss. Just because you have an engine that will put out the rpms does not mean it has the power to hold them in the air. The Jett does.

jett
 

well i had a jett fire 60 that couldnt hold the rpms in the air too. ended up trashing the engine after only 12 runs. the jett service is great and it was rebuilt without question. that engine spit head bolts out every run, overheated in the air after only two minutes and barely got the DD to 100 mph. i dont judge all engines by one bad one.
Mr. Cyclic please relate your personal experience with the os 46fx.

Sport Jett .46 vs OS .46FX?
 

46fx-I owned two of them and swtich over to TT46pro due to cost. They both perform exactly the same and i have no complaints but they are flat out not the engine he needs for the results he wants out of that Patriot. This is not a 46fx slam by any means. It his money not mine. I see people wasting their wallet everyweek on bad advice.
* Up until a few weeks ago, I was running a MVVS.40 size Q500. Morris Hobbies claimed it would put up with a YS.45 and possible Jett 50. With a 9/8apc and 17000rpms it was a nice smooth running engine and reliable but it would not pull a 6.5lb plane any better than a standard 46. Once in the air it could not sustain the power. So I unloaded it for the Jett .50 and i have achieved the results i want.

mvvs 40 vs jett 50
 

This is not a fair comparison. The jett 50 is 25% bigger than the 40. The question posed here is 46 vs 46. How much better do you think the jett 46 is over the 46fx with similar setups?

My experience
 

With a $60 UltraThrust muffler on a 46FX I was able to turn a 9x7 at 16,400 rpm. A stock Sport Jett 46 will turn a 9x8 well over 16,500 rpm. The Jett is still running after the 46 FX gave out with the abuse of high rpm. I like the 46 FX but it is not a Jett. :)

Sport Jett .46 vs OS .46FX?
 

Somehow your not getting this and I do not think you will. The man is building a Patriot and was asking about a Jett.46 up front. We are trying to swtich the man from the Jett.46 to the Jett.50
because with the .50 he will achieve the results he wants for only a few dollars more.
* This is a no win situation with you sir. My boy has an Advance .40. Nice plane. I had a TT46pro up front with a 10/7apc. It hauled it around just fine. Nothing fantastic but okay meaning maybe 60mph and vertical was marginal but no complaints. I decide to put a 61pro on the plane.
*Now i take this 46pro with an Ultrathrust and throw it on a 3lb Shrike and it goes a simple 125mph respectively here at 5000ft. At sea level I am sure it would be around 140mph. Not bad for a simple 46pro?
*Its the same engine that poked around at 60mph on the other plane. The Jett is built to withstand the beating I am giving this 46pro. I am running alot of oil to keep it from blowing apart.
* Your telling me a Jett fire 60 could not take a DD to 100mph and my 46pro can cruise a DD all day long at that speed, Something is definately wrong here with this picture. 99percent of the time, overheating is "pilot error."
*Whatever the case this is Mavericks thread and if he wants his Patriot to zip up in the 140-150 area, then the Jett.50 will get him their. Proper maintenance will keep it their. Rossi also makes a couple of hot ones but I would not touch them because of customer service is horrible
I've had it with this thread, I'm done with it.