AraTidwell

Hi,

I fly an Aeroworks profile and I love that plane, but it is about 1/2lb heavier than kit built varients. I am running an OS 55AX with a Evolution / Jett performance exhaust and getting 14,500rpm out of an APC 12x4. I only got about an extra 500-600rpm vs stock with baffle removed. I am under the impression that the OS is not tuned for high revs but I am no expert.

What RPM's are guys running TT Pro 46's with APC 12x4's? I'm kind of thinking a TT Pro 46 with a tuned exhaust might out turn the OS 55AX.

Alsoin this thread I'llaccept 12x4 APC numbers from other 46-60 class engines as well. Just note stock/baffle/tuned exhaust please.

1QwkSport2.5r

I'm not so sure a TT .46 will turn a 12x4 better than the 55AX. I could be wrong - I havent spun that big of prop on my TT .46 yet, but It will spin a 10x6 at 14,600-14,800rpm with a Jettstream pipe (1000rpm over stock TT .46 unbaffled muffler). I'd guess it'd come in at just under 14,000rpm on a 12x4 but thats a total guess..

AraTidwell

I am pretty happy with my OS 55, but they raised the price to $169 which is just retarded. I had a TT Pro 46 a LONG time ago and I know it is just as good as the OS 46FX. I need to know if I can recommend this engine with an Aeroworks ProX260 profile which is 4lbs 15 ounces and has a very thick wing blocking some thrust. The stock 55ax bearly got 1:1 thrust, taking the baffle helped some and the Evolution Performance exhaust a bit more...

I would recommend a 60NX but I've heard mixed opinions on them as 3d engines. They have remote needle valves which in my experience slow throttle response.. I have a couple of theories but I donno.. just been my experience and people will argue about this one until the end of time.

proptop

My Feedback: (8)

2 of my TT .46 Pro engines...both with the cheapie Tower muffler (15 bucks ) turn an APC 12 x 4 at 14,000 and 14,100 on 15% Nitro Powermaster.

I would expect them to pick up at least a few hundred with a Jett muffler...so I guess that would make them at least equal to your O.S. .55AX?

From all I've read about it, the .55AX isn't really ported and timed to be a high r.p.m. revver.

If you are looking for more pulling power, I have seen others recommend the 13x4 Sport APC prop...don't know how well that would work w/ the Evo / Jett muffler though?

AraTidwell

When I was running the OS 55AX with the stock muffler and baffle out, the 13x4 didn't pull quite as hard as the 12x4... go figure. I suppose I'll try running it again and see what kind of result I get.

proptop

My Feedback: (8)

Oh...so you have already tried the 13x4...what sort of r.p.m. were you seeing?

Is that the 13x4 Sport, or the 13x4W?
13x4W is a wide and thick airfoiled prop that puts a lot of drag on the engine...and it's heavy.

I was just throwing it out there...
Don't know if the 13x4 would pull the r.p.m.'s down below the effective working range of the Jett tuned muffler?
Would still be worth another try though.

AraTidwell

I do not recall my RPM, but it was the narrow blade 13x4. The Evolution manual says that it should be propped for at least 15,000rpm for whatever thats worth but you know manuals aren't always right.

fredscz

My Feedback: (47)

Just happen to have some information that might be useful. Same day, same props, same fuel (15%Omega).
very used thunder Tiger 46 with stock muffler and baffel and idle bar plug which probably hurt the rpm some, and also with a performance specialties muffler.
TT46 very used Stock muffler PS muffler
apc12 3/4 X 3 3/4 12,100 12,750
APC 12x5 12,000 12,700

Almost new OS55AX stock muffler W/baffel A8 plug
APC 12 3/4 x 3 3/4 13,500
APC 12x5 13,300
old Wood 12x5 12,750 In the air this prop seems to have as good or better vertical than the others even though the ground rpm is less

JohnMcGowan

My Feedback: (15)

Ara, I dont know if you've tried this prop or not on your TT46, but give the APC 12.25 x 3.75 ( 12 and 1/4 x 3 and 3/4) funfly prop on your plane and see how you like it over your 12x4. It produces tons of thrust if you are into that kind of thing with your profile.
Coincidently, my middle name is Tidwell ....( that was my mother's maiden name)
John

AraTidwell

John,

I have tried that prop long ago, not sure if it was a TT 46 or a 46FX... but I did not like the prop because it heavy and slowed the instantanious throttle response a bit making some 3d manuvers impossible.

AraTidwell

Fred,

Those numbers are impressive for the 55ax.

fredscz

My Feedback: (47)

ARA T The one 55 that I fly the most (has the most run time) is a lot stronger now but I have not used a tach on it. I tried a PS muffler on it and it really screamed (very loud also)but I can't find the paper I had the rpm readings written on. The 55 may not be a 18,000 rpm engine but some very knowledgeable people on this site and others said the engine put out the best power if you tach it to 13,000-13,500 rpm on the ground and I have found that to be very true for my use. I use the 12x5 military surplus wood prop on one plane and the throttle response is like an explosion. Several years ago they sold those props for scrap prices but the only ones I have seen lately are way over priced. The 12 3/4 x 3 3/4 prop has never worked very well for me.
Fred

AraTidwell

I agree while the 12 3/4 x 3 3/4 might make more thrust while static it does not spool up well and it has been a while since I flew it but probably not as good verticle speed if your 12x4 or whatever setup is past 1:1. It really makes me wonder when I hear about all those guys sporting those heavy props... they must do nothing but steadily hover because that is about all you can do.

asmund

I think your numbers on the APC 12-4 is about what to be expected. I have a modified ASP .52 XLS and a modified JBA .56F and they swing that prop 15200 rpm and 14900 rpm respectively. Both fitted with the red Jett muffler.

I also agree with others that the APC 12.25-3.75 lack in fast spool-up, I much prefer the APC 12-4, or a wooden 12-4 or 13-4

757jonp

My Feedback: (48)

My son and I fly both the 40 size Mojo and Primo with 55AX engines dead stock, no mods. After much testing using various props, we both settled on 10 X 7 Master Airscrew as the best prop for 3D with this engine. I've never even put a tach on the engines, but with that prop, you'll enjoy how it provides instant acceleration and unlimited vertical. Top speed of the aircraft is rather reduced compared to the APC 12.25 X 2.75, or 13 X 4's, etc., but speed wasn't what I looking for, I want "punch out" power.

Give it try, it might surprise you.

DarZeelon

A 'Magic Muffler' type tuned-exhaust can work well in this application (i.e. a 12x4 prop is definitely for 3D).

A full-length tuned-pipe is out of the question. It just cannot respond and transition as well.

AraTidwell

Asmund,

Want to tell us about your modified ASP 52 XLS? front or remote needle valve? What mods and how much RPM did the mods give you? other comments?

airraptor

My Feedback: (66)

you need to get a Four stroke to get more thrust for 3d or put a 95 AX in it

AraTidwell

A 95AX would be WAY too heavy. A Saito 82 would be perfect but the people I would recommend this combo too do not have that much money.

freakingfast

My Feedback: (3)

An APC 12X4 is a bit light and the 13X4 a bit much for a 55AX on tuned muffler or not. And the problem with larger disk area, low pitch props like APC 12.25 X 2.75 is the engine soon hits it's rpm lmitation and falls on it's face where smaller, higher timed engines keep revving. The 55 needs loading but cant rev out, so you may love a Master Airscrew S-2 series 11X7 (not the black one and not APC) or get some brand of 12X5 to keep the engine in it's power range. Both props will yield over 10lbs of static thrust. An APC 12X5 will have smoother power and better low speed idle (heavy prop), then try a Zinger Pro AND plain Zinger 12X5 (it's low mass) and look for which one will give you that jump of the ground effect you need. The 55AX/tuned muffler with 11X7 will hover alright, but top speed is insane on a 3D plane, perhaps flutter inducing, so be careful. Engines with baffles out or tuned pipes and tuned mufflers can be problematic with mid range(hovering) for 3D, sometimes the right prop can help so play around.

AraTidwell

I'll try the APC 13x4 narrow blade prop again, but last time I tried it using the stock muffler with the baffle removed... It made slightly less thrust than the 12x4

MrGreenSpeed

I find the APC 11.5x4 to be a good choice on 46 size engines.

Good luck.
Jeff

daven

My Feedback: (1)

I was going to recomend the 11 1/2" x 4 as well. It will scream on there.

freakingfast

My Feedback: (3)

I wasted my time[sm=spinnyeyes.gif]

camiloro

good day

i have a prox260, with a os55AX, but i need information about the installation of the engine, As someone has the holes for the engine, for this balanced