Yellowsierra02

I have a OS .55ax in my pulse xt 40. Its a pretty quick plane. It radared in at 103mph in a slight dive. I am using a APC 10 x 8 and 15%nitro fuel and it turns 13,600 with this combo. I'm wanting a little more speed. I just ordered a Ultra thrust tuned pipe which should wake it up alittle. I was wondering if I could use 30% nitro to get some more rpms/speed out of it. I was also thinking about using a 10 x 10 apc prop to get more air speed. I was also thinking about trying a APC 9 x 10 prop. What do you guys thinK? I would like to get 120-130 moh out of this plane. Is this possible? Is the higher nitro a good idea? Ive heard its alittle harder on the glow plugs and you will have reduced flight times.

Thanks

Justin

rmenke

My Feedback: (13)

Yellowsierra02:

At the risk of being expelled from the forum, I think you are beating a dead horse with the OS 55. The motor is designed for normal sport use and not timmed for higher rpms. It is a good solid sport engine, if abet' a little over priced. Yes, you can get a increase in rpms with a Jett Stream tuned muffler, or equal Nelson "ultra thrust". You may see from 500 to 800 rpm. Do you have a heat temp. meeter. If not, get one from your local auto supply store for around $20.00. Run the engilne with the recommended prop and get a baseline temp. Now stick on the 10 X 10 apc. If the temp. jumps up and starts to climb over say 250%, you are risking heat damage. If you want a 10 X 10 prop, try the OS VRDF90 and enjoy 20-24,000 real rpm horses, or BVM for more yet. Or, spend less money and get a Webra 55 and Jett pipe. Will for sure pull the 10 X 10 in the area of 18,000+ and shock the gang. Must be broken in correctly, go to the Jett web site and read all about correct proceedures. Combat Pig put me onto the motor and prop last year. In same airframe, the Webra 55 would lap the OS 55, & K & B 48, OS 61's twice in 10 laps with ease, and hang with a Jett 60LX yet. Yes, the Jett was obviously faster down the streight, pilot just unable to beat old age and tretchery, he he. ENJOY

Yellowsierra02

I would like to stay with the OS for a month or two then put it in a Avistar. Im trying to decide on a fairly quick engine for under $400. I was looking at Rossi .53 with a nelson ultra thrust pipe. They go for under $300. What would be a good fast motor for this plane?

Thanks

YUKONFLYR

Rmenke -

Have you used a BVM with a 10X10 on it? I aquired a BVM .81 and was wondering what it will spin with a 10x10. Would you happen to know the front stud size / thread pitch?

Any Mods to run props on the BVM?

Yellowsierra02 - got the BVM 81 off of RCU for under $200.00, now that ducted fans have given way to electric and turbines they are all over the place.....cheap!!!

Richard

brewski

Be very careful with the 55 in the pulse. A friend, flying his Pulse, was pulling hard around pylons in a friendly race with me when something didn't feel right to him. He got it down and the fuselage was broken from the wings pulling so hard. The Pulse is a great flyer but more for mild aerobatics and may be a little fragile when it comes to speed and high g force of a 55 AX and certainly a Webra 55 unless you do some mods.

freakingfast

My Feedback: (3)

Yellowsierra02:
With your new setup(tuned muffler) try an APC 10X9 for speed, it should turn around 14600 peaked. For climb and nice all around fun a Master Airscrew 11X7(S-2 series) turning 14000. 30% nitro wont gain much and it is hard on that engine, stick with 15%. It's a great engine with after market exhaust. enjoy.

Make sure the covering is down and tight on the fueslage first than drip in some thin CA chased with thick on the inside of firewall joints and wing hanger area joints, some ARF's need more glue or it could fall apart like brewski's friend[&o]

freakingfast

My Feedback: (3)

YUKONFLYR
Be careful, an APC 10" diameter prop's max safe speed is 19k. Take a wild guess at what a BVM 81 will turn?

propfragmentus [X(]

YUKONFLYR

Freakingfast - Im hoping for lots of RPM's like 20,000+[&:] and I may well be beyond APC's safe limit for RPM's[:@] May have to get a Carbon 10" or set the test stand up with a blast shield for a full throttle run

I would like to use a Mac's pipe and tune it for low 20,000's or so. Know anyone who has done this?

Thanks

Richard

Yellowsierra02

I'll let you guys know how it turns out. I thought my pipe would be in today but I guess it will be here tomorrow. IF I decide to try 30% I will probley try a quart. If its a little to much or doesnt gain much rpm add it to my half empy gallon of 15%.

Justin

bob27s

My Feedback: (19)

The OS 55 is a heck of a good engine. With the right prop it runs great. Some guys are SERIOUSLY over-propping the engine. And the engine really enjoys the tuned exhaust. Its not agressively timed, so do not look for monster rpm. But it does develop power very well at reasonable rpm.

Keep the 10x8 and bolt on the ultrathrust.

You want the OS55 engine turning between 14,500 and 15,000 peak ground rpm.

If you have 13,600 rpm now, you will be right in that range with the 10x8. (Gain is typically 1200-1500 rpm -- just like the jett-stream muffler)

More prop and the muffler will not be in its best rpm range. So more prop is not the correct approach right up front.

Don't change the fuel.

After running the 10x8, you can try something like a 9x9 for a little speed. Maybe try a 10x9 if the rpm range seems consistant.

You will definately gain in speed and the engine will run great. But I think gaining 30 mph beyond where the plane flys today may be asking for a lot.

Yellowsierra02

Yellowsierra02

Thanks for posting all this great information! I finally got to do some runs with the ultra thrust pipe! Wow is all I have to say. All the runs where with byron 15% nitro and APC props.


OS muffler without baffle 10 x 9 prop = 12,900


Ultra thrust 10 x 9 prop = 14,600

Ultra thrust 10 x 7 prop = 15,500



Overall I was very happy with the results. Now its time to go to the flying field to see how much speed I will pick up!

Justin

freakingfast

My Feedback: (3)

Hummm, where have I seen that 14,600 number before?
That's this engine's sweet spot, it leaves room to unload in the air and reach the peak power where it counts.
The 10X7 is too light a load, in the air the engine will hit a wall and not go any faster, the port timing and flow is at its limits.
Have fun!

Yellowsierra02

Yeah it sounded beter with the 10 x 9 prop. I think it ran alittle cooler too. I was wanting a 10 x 10 but they where sold out. Im going to try the 10 x 9 in the air for now and try the 10 x 10 lator down the road. I like the little OS motor. It starts good, runs smooth and really has plenty of power for my airframe. I would like to try a Rossi 53 down the road. Ive heard the rossi's are screaming little motors. You can get the .53 with ultra thrust pipe for $279.99

freakingfast

My Feedback: (3)

The 10X10 is too much, it will lug down once it un-stalls "hooks up" in the air. I think you’re at this planes limits, it's over powered as it is. You have a good package now (10X9 & Ultrathrust) and if I were you I'd keep it as it is as a fun/warm-up plane and at about 120mph I betcha it's faster than 99% of anything else flying at your field. Inspect it frequently for things getting loose and listen for flutter or it could be raining balsa[:@]

A Rossi .53 deal? Sounds like you are coming down with "speedfreakyitis" and there's no known cure. It is most easily and quickly managed by exposure to Demon or Viper smoke

Face it Justin, you need a faster platform for the Rossi if you feel the need for more speed.

Yellowsierra02

Yeah I think Ive had "Speedfreakyitis" for some time now. haha I had a foam Funjet that was cloacked @149 mph. It pushed out about 1400 watts of power. My first plane was a Tower trainer 40. I sold that plane and flew nothing but electric and now Ive feel in love with nitro/gas planes! Theres nothing like it. I like electric planes but there kind of boring compared to gas! Your right about needing a faster airframe. I would like to have a plane that does 150+mph. I think Im going to go all out and get a Viper and a Jett 60 BSE. That should get it done. Is the Viper controled by ailerons and elevator? Im guessing it has no rudder?

Justin

freakingfast

My Feedback: (3)

The Viper has "V" tail and you need mixing to use it right, most newer transmiters have it. The mixing will give you rudder. Start out with a inexpensive engine like a TT46 Pro incase it goes bad/ learning curve. With the right prop it's an easy 125+. Read the threads to find the mods & fixes, easy. The Rossi would be a good engine for it. The Jett 60 may just pull it apart. The Jett may be at home in a prop jet doing 160+

I don't know how sick you are, perhaps a dose of Nelson LS + Q40 or F3d would calm you down?[>:]

Razor-RCU

My Feedback: (50)

The Rossi-53 and pipe is WAY too close to the price of a Jett-50 or 60LX which are faster/superior engines. I have had both and tested both the Rossi-53 is good but not in the same range as the Jett. Heck have you considered the West-50? It is $300 but it screams like a Jett

Yellowsierra02

Yeah Im definatly going to get the jett 60 bse. I dont want to get second best and be sad because I didnt spend another $100 to get the best. Im probley going to get the Jett 60 and a Viper 500. That should get me to 150mph if not more.

scoeroo

My Feedback: (9)

Check out the engines for sale , I've picked up some good used rossi's for around the $140 mark , good value at that price and will haul the arse out of a viper with a 8.8x9 apc pylon prop.
Not legal for any class racing but good to keep the reflex's in shape and to generally have fun cheap.

YUKONFLYR

I would have to agree with Scoeroo,

Check out the used engine ads, since Jett introducted the QJ2 there have been several Jett Quickee engines for sale and nelsons two, for under $200.00. Yeah...there is no throttle, however you could get a carb for a Jett Quickee engine so that you would have throttle, ..............that would be contraindicated to your "speedfreakyitis" illness that would most likely guarantee that you would never throttle back anyway

I Picked up a very used and at least a decade or more old nelson that still cranks a APC 8.8 x 8.75 to about 18,600 on 10% Omega, for only $150.00. Another that I aquired for about the same price cranks the same prop to 19,500, good for a few kicks and not a great loss if it augers in. At least a lot less pain and suffering than if you augered in a Jett BSE 60lx[X(]


Freakingfast - LOL....."speedfreakyitis"......"no known cure" LOL "easily and quickly managed by exposure to Demon or Viper smoke"...[sm=lol.gif][sm=lol.gif], your killing me