I have an 85" Corsair with a Saito 3 cylinder radial 4 stroke gas. Haven't fired it up yet but can't wait to hear that sound.

Just to clarify I meant 4 stroke when I said 4 banger,sorry for the confusion ,now as far as engine choice I'm still looking for a good 2 stroke in the 120-140 range.

The DLE 20RA looks like it would make a good inverted engine with it's rear exhaust.

The OS 120 AX is an excellent choice. The Ultra Sport is so clean, aerodynamically, that a good 120 2-stroke will give you great performance.

Jim

Would anybody ever consider putting on a moki 140 or 135, on a us 1000?

The only problem I would have with putting larger glow engines like that would be the cost of the glow fuel. I run 15% fuel at and around $20/gallon it can run into some money in a hurry running a large glow engine. That's one reason why I've started going with gas engines in anything larger than a 90-sized 4 stroke any more. As I said earlier, I think this is one of the reasons that they US 1000 never really was as popular as the two smaller versions. The bigger glow engines just cost too much to run.

Now on the other hand, the two engines that you mention would be sweet on the front of a US 1000!!!

Ken

Ok just checking to make sure I'm not crazy.

I ran a Super Tigre 2300 in the front of my Ultra Sport 1000 and it flew like a scalded dog it would fly as fast as I wanted and unlimited vertical. Sadly my US 1000 met its fate one day when the battery gave out she is gone but not forgotten.http://www.rcuniverse.com/forum/atta...mentid=2048234

Looks good

That was a good looking plane. Such a shame whenever one is lost. :(

Ken

I hear this argument all the time from people who have no experience with large glow engines. I run a Moki 210, a Moki 180 and a couple of OS 160s. All of them will run on zero nitro (FAI) fuel. I run them on 5% because they idle a little more consistently on that. But any higher nitro is a total waste of money on these engines. I buy 5% Omega in a four gallon case for $13 a gallon and a case will last me 6 months to a year. Yes, a big engine will go through a lot of fuel at full throttle, but who flies those at full throttle all the time? With normal throttle control, a 10 minute aerobatic (not 3D) flight with a Moki 180 will burn about 8 oz of fuel. At $13 a gallon, that is about 80 cents a flight. Round that up and ask yourself if $1.00 per flight is too much for Moki type performance.

Jim

Good post jrf.

Jim,
You are absolutely correct, and I'm not arguing your point. I run 15% fuel simply because that is what I started with when I was flying smaller .46-.60 sized planes, and that's what I fly now so simply stick with it as I still have several planes that I fly with those size engines in them. I like the way they run with the 15% in them so I stick to it. I know that I could go to a lower nitro level and still be ok, but I choose not to. But if you re-read the post you quoted you will see that I said that I run 15% and it costs $20/gallon. That's my cost and that was my experiences. However, using your costs of just $13/gallon for fuel it's still more expensive than a gallon of gasoline and around $3/gallon at today's prices. And that is the case that I am making here in why I think the US 1000 never really caught on really big. If we had the cheap gas engines back when the US 1000 first came out I think that the US 1000 would have been much more popular. Those big glow engines are what held back the US 1000, in my opinion.

Ken

Ken:

I run 15% in my 40-60 size engines also. And yes, running gas is generally cheaper than running glow in the same size airplane. (At least it is after you amortize the added up-front cost of the gas engine.) I'm just saying that the cost of glow fuel for the big engines is not as bad as people seem to think it is. And you can get outstanding performance from an Ultra Sport 1000 with a big glow engine at a reasonable cost.

As far as the reasons that the 1000 wasn't as popular as the 60, I'm sure engine and fuel costs held a lot of people back. Retracts for a 12-13 pound airplane are not cheap either. And don't discount the one-piece wing. A lot of folks can't transport or store a wing that size. Giant airplanes are not for everybody.

Jim

All facts are true with regard to fuel consumption , its good to try new things and see what works.
Stoner.

Which engine to use : These are my engine choices moki 135 or a 140. Would the 180 be too big for the us 1000?

You got this one right. We just ordered the retracts for the US 1000 that I'm building for another US Brother here on RCU. We are going with Robart electric retracts and we are going to being doing a trike setup with a nose gear on the plane. Cost for the retracts were $630!!!!!

Originally the US 1000 didn't allow for a retract setup with a nose wheel because with a glow engine the fuel tank needed to be right behind the fuel tank. But with a gas engine we can move the fuel tank back inside the fuselage (I'm moving to directly above the CG) so that I have now have room behind the firewall for a retract gear to go in. We're going with a 100 degree nose gear that has the nose wheel raked just a little bit forward giving it a look like a fighter jet. Should look pretty cool!!!

http://www.rcuniverse.com/forum/atta...mentid=2048527

As I get a little bit caught up in some other thinks that I have going on I plan to start up a build thread on this US 1000 build, so please don't yell at me for one!!!! :)

Ken

stoner: The Moki 180 is a lot bigger and heavier than a 120 or even the OS 160, and you can't really use the extra power in an Ultra Sport 1000 unless you want to go 150 mph, and that gets old after a while.

I have tried the 135/140 Mokis, and unfortunately they have not been as good as the bigger Mokis. I do not recommend them. Check EBAY for a good used OS 120 AX or 160 FX. I had a 1000 with an Italian made Super Tigre 2300 (1.40) and it was awesome. More power than I could use, but not as reliable as an OS.

Jim

No reason given ?
 

Hello Jim,

I am interested in the reason(s) why a Super Tigre 2300 (1.40) is not as reliable as an OS ( in your statement ) ..... ( opinion ? ).

Your explanations would be well appreciated.

Althoug I bought an OS 55 AX for my Kadet Senior, the mods I am doing and reinforcements will make it quite a bit heavier and if the OS is overloaded I may use my nearly new Super Tigre G 90 .

Zor

I'm just trying to stay away from os. But if I have to I will purchase one.

Lazer- Works can cut you an UltraSport 1000.
http://lazer-works.com/rcm.html

Zor:

My experience is all with the Italian Super Tigers. Never tried one of the Chinese ones. I found it very difficult to make the 2300 ST carb work. We used to have an expert ST tuner here but he was not very available, so I installed a Perry carb. Much better, but it would still dead stick occasionally for no good reason. I've never had that problem with OS, and never had to change the carb.

I have also had an ST 90 or two. (I've been in this hobby for 35 years.) The carbs seemed easier to use on those, but boy, do they vibrate! I always balance my props, but I was tempted to unbalance the prop on those to counteract their inherent vibration.

Try a 13x4w apc on the 55. You won't believe the pull you get from that prop.

Jim

My US 1000 also has a ST 2300 - Italian, bought used for $28.00. Running an APC 16x8 on 5% fuel and a Perry pump carb (but without pump), I have unlimited vertical. I use a hot plug, like an "F" or "Miracle" and don't have any issues with dead sticks. No problems with fuel draw, even with the huge carb and a Pitts muffler with both tubes open. Sure is fun!
Jim

http://www.rcuniverse.com/forum/atta...mentid=2048643

About Super Tigres
 

Hi Jim,

I understand your experience with the Super Tigre engines.
I also had some carburetor problems but solved it.

I cannot tell where my G 90 was manufactured. Initially I experienced transition problems from idle to max power. I said to myself that the piston-cylinder is nothing but a compression chamber so I took the carburetor apart. I found that the opening where the fuel is drawn into the engine referred to as "the cat's eye" was not deburred cleanly and actually a couple of burrs were loose in there.

I prceeded to clean this up and polish the cat's eye opening. No more difficulty to adjust the fuel ratio and bench tests proved the problem had disappeared.

It worked fine on my Super Skybolt untill I decided to replace it with a Saito 125a.

Thanks for the advice about the OS 55 AX and the prop. I am on schedule to start building my Kadet Senior in early December.

Zor

Would anyone ever consider putting a moki 140 gas conversion engine on a us 1000?