markhamregular

I am an OS guy and I have never bought anything else. I also like only glow nitro 2-stroke.I am ready to make the leap to a fast engine. Usually, when someone tells me an engine is powerful, I always hear about how complicated it is to tune them.Can anyone share their experiences with fast glow 2-stroke nitro engines?Thanks,

earlwb

Buy a Jett engine and you have a fast engine. No messing around with trying to tune the engine for more speed you just use it. You use a Jett tuned muffler with the engine and you don't have to tune it either.

Now if you want to "tune" your own engine, then you need to buy several of them. Then you carefully make the changes and log carefully the results of what each individual change does. when you make a change that makes it worse, you bin that engine. Then make all of the changes for the next engine but stop short of the change that made it worse. Then you would have a fast engine. You might want to make spares up too. usually the engines at max RPMs tend to wear out faster.

123Cat

The West Eurotechs set how they say are very good, Ive used them

Jett with their pipe



30% nitro in your OS with the right smallish prop is very good and reliable

vicman

My Feedback: (10)

I love me a Jett as well. The .50SJ is a great easy running FAST engine.
You will absolutely love it!

I also like some of the older MVVS engines. .28, .45, and .49 are the ones I have. They are a good go between for an OS and a Jett.

BillS

You already know the following.

It is often stated that wings are only necessary for take off and landing. Wings produce drag. Drag reduces maximum speed. Thin wings produce less drag than thick wings. Short thin wings produce even less drag.

Every design is a compromise. Turning the prop faster usually means a faster airplane.

There is nothing new here. You already know all this.

Bill

NikolayTT

I would try the engines used in the RC-cars, some reach up to 40,000 rpm just like that. Some fellows may say that those are small displacements, but that is on my opinion good if we consider the Diameter of the Propeller and the Linear speed of its tips. Even with 6 inch propeller 30,000 rpm gets the tip beyond the Ultra-Sound speed and to ... dangrous desruction. So I would ask the Question: - Yes, Fast Engine, but with what kind of Propeller ? - Well, mabe Impeller then but that is 'a bit' strange use of combustion engine, isn't it...

Cheers, Nick
(also OS fan, beside the Italian SuperTigre an Rossi of 'good old times')

NM2K

My Feedback: (14)

No argument from me for the Jett Engineering recommendation. None at all.

However, if money is in short supply, one could consider buying a used Jett Engineering engine. Yep, you might get burned. Be careful.

Then there are Webra, Enya CX series engines, Rossi, Novarossi, Picco, OPS, Irvine and Super Tigre engines that are still floating around out there NIB. Not brand new, perhaps, but they could be NIB. I have a NIB Webra .50 GT that I might let go of if a good price or a trade is available. What for example? A NIB OS FS-20 would do the trick.

And of course there are the YS two-stroke engines. Especially the round headed two-stroke versions. Yep, they be the older versions. Save the long and four strokes for those that need them.


Ed Cregger, NM2K

NM2K

My Feedback: (14)

Sorry, double post.


Ed Cregger, NM2K

123Cat

The 40 and 50 mm diameter scorpion electrics are doing between 375 and 450 Kilometers per hour in the Speed Cup events

1QwkSport2.5r

The fast engines are going to be Jett or Nelson. I have a BSE .35 myself. They are NO comparison to an OS. OS is stinky toe-jam compared to Jett. Jett's run best on 15% nitro, but will run on low/no nitro fine also. Drop 1" less pitch for FAI fuel.

RC car engines rarely ever have a long enough crank to get a prop on it. Besides, the big heat sinks on the head make them run way too cold with that much air moving over it. Best bet is a purpose made aircraft engine, IMHO. I've ran car engines for 15 years, 20-30% nitro and 38,000rpm would get expensive. My .28 monster truck engine burns 7oz in about 7-9 minutes.

earlwb

Car engines are marginal at best in a airplane. First they have too short of a crankshaft end, no drive washer either and many comes with a short threaded crank end and a clutch adapter tip too. Then there is the head which has too many cooling fins and needs to be machined down, but how much do you take off the top though? Also the carburetor is all wrong, with a push pull throttle on them that is difficult to impossible to use in a airplane. Finally, the car engines might rev up high, but they only do so for a few seconds not a long time, thus with a little tiny prop on them so it'll turn 38,000 RPMs, won't give it any quick airspeed in a airplane, the take off roll will be about 500 yards long, so allow for a long runway and the plane may stall out in the turns too.

Ultimate speed is the slope soaring speedster planes. no engines, no motors, just gravity and air and wind. They set all the eye popping amazing speed records. Engines actually slow them down too much.

But at present Jett engines are the way to go. Nelson used to be "IT" but he quit making engines though, but his engines are still really good. Years ago it was Rossi, but the fastest Rossi's were "tuned" to run even faster too. Picco and NovaRossi are still good, but aren't as good as Jett engines still.  One could check out the Pylon racing engines as well, they have had a number of those do really well for speed too. Many years ago before Jett was around, I used to run some Rossi engines and the full throttle high speed low to the ground fly byes were always fun to do. That was running a Rossi .60 on a .40 size plane with a thin wing.

But all out racing engines, only have two throttle settings, off and full throttle. If they have a carburetor on them at all, it is for killing the engine after the heat is over. The engines are tuned to be all out racing, no compromises, so tractability is not going to be there. For racing and speed they are the kings, but for sport flying they are really bad. it is like trying to drive a Daytona 500 race car on city streets during rush hour, or trying to drive a 1200 hp nitro-fueler superchargered dragster on a city street with a 30 mph speed limit.

Now with Jett engines you can get all out racing engines or their not quite so hot sport Jett engines that have more tractability to them so they behave better and have a throttle that works.

markhamregular

Thank you all for all your ideas. I am going with the Jett.

A friend at the field this morning who had Jetts told me the 56LX is the very best.

However, I see they have a new 60 that will probably be better for the Patriot.

Anyone has the new 60?

Thanks,

1QwkSport2.5r

The website is grossly outdated. The 56LX replaced the 60LX. The 56 is a friendlier engine I guess.

I have a 56LX on my wish list.

NikolayTT

Well, maybe good idea is to look at Results(!) of
Class F3S and see which Engines make history in
the Speed Records; you may enojoy a lot:

http://www.youtube.com/watch?v=zyRQ65pDmW0

and also

http://www.f3s-speedcup.de/


Cheers, Nick

NikolayTT

Maybe best sourse is:
http://www.rcuniverse.com/forum/m_11...m.htm#11192615

good to see ...

vicman

My Feedback: (10)

I just caught that you are going to put it in a Patriot? 56LX and forget the rest. You will be verrry happy.
Here is a link to a speed event in the US that allows all types of airframe engine combinations. Check out the spreadsheets to review the data. Yeah, its a radar gun...but a good one

http://www.caldwellaeromodelers.com/speedrally.asp

earlwb

Yeah if you are running a Patriot, then the Jett 56LX is the engine to use.

iskandar taib

My Feedback: (5)

Car engines turn high RPM because they're lightly loaded. Put any sort of meaningful prop on them and they'll not keep up with a proper airplane engine. If you want a fast, small engine get a Fora. They're designed for F2D and turn about 29-30K with a 7" prop - you'll need to get one of the fiberglass toothpicks they sell with the engines, or use, say, a MA Scimitar 6.5x3.5.

A somewhat bigger engine? Hunt e-bay for Nelson engines, you'll probably find someone's old Q500 engine for sale, that'd be fast... probably way too fast..

Oh wait - what's this - you want a SPORT RC engine that actually has a throttle?? In that case, go with the majority here and give Dub Jett a call...

Iskandar

airraptor

My Feedback: (66)

None of what you said will be fast in an AIRPLANE..

mike109

G'day

There used to be a couple of blokes at my club that tried to go fast. They were flying Skyraider Mach 2 planes with OS AX 46 engines. They tried different props, more nitro, lean tuning and all they achieved was to make a lot of noise and to ruin some motors. The flutter from their over speeding airframes was memorable. But they did not go really fast.

So I decided to show them a real engine and I bought a Jett SJ 46. I did not have a Skyraider but I did have two identical GP big Sticks. I put the Jett in one and an Enya 45SS in the other.

The original Stick with the Enya was good to fly but a little slower than their Skyraiders but the one with the Jett 46 was very much faster.

I did measure the Jett's revs. When it was running in on a 9 x 7 (as recommended) on 10% fuel, it was turning 18,900 and this was tuned rich. On a 10 x 6 it was turning 16,500 also rich.

I don't know what the other engines were turning but it was probably in the 12 - 13,000 range on 10 x 6 props.

If you want to go fast. Buy a Jett.

Mike in Oz

NikolayTT

After all the Results is only what matters. Check the F3S, there (seem only(?) in Germany)
among the fastest and in a stable mass production engines are still OS Max .91 and the
Electric ones. - http://www.rcuniverse.com/forum/m_11165411/tm.htm

Hossfly

You don't say what size you want. You speak of how do they handle. Speed engines are finicky. An engine for FAI racing, 80% methanol, 20% castor oil will go fast given a compression ratio of 20:1 but that is "L" on glow plugs and start-ups. So you need to decide what you really want. AFAIK, Nelson is long gone. I have a Nelson .90 some 17 years old still in great shape, never a prop or fan on it. It is labled Bob Violet, but was for ducted fans before the turbines took over.
Incidentally I also have the "Maverick" that I bought along with the engine. All still in the box.

High performance requires high maintenance.

markhamregular

I bought a Jett 56LS. It's coming in 2 weeks. My Patriot is sitting pretty at home waiting for her engine.

Can't wait to finally have a fast plane.

Sport_Pilot

You still see used ones for sell now and then. I suppose they are usually either worn out or like new, not often in between.

fizzwater2

My Feedback: (61)

Nelson's aren't gone...

you can still get new Q500 and Q40 engines from Mike:

http://aeroracingengines.com/about.html

He's manufacturing them now.