rmh

The 40 size muffler from RCS is extremy quiet - the most quiet of ANY setup on the 40 I have flown- I flew this on to different models.
This can -the JMB, does NOT add any power but is very easy to setup up as it is not gcritical to header length.
Howeve -although it is not a device which uses resonant tune - it also does not kill power as some pieces of s--- sold as mufflers are prone to do.
So you may easily see more power over some of the plumbing rejects ,marketed as mufflers.

rmh

-Hmm -I think I should have checked for spelling errors, on that last post!

Steve_JR

My Feedback: (6)

This is the prop I have on my H9 T-craft, It is a Biela 20x10 carbon fiber prop with white gel coat and red tips. -Steve

cwboomer

who sells those props?

Iflyrc4fun

My Feedback: (132)

Go to www.tntlandinggear.com. They carry Beila, Mejlick, 3-W, Menz, Prince P-tip, APS & Top flite props.They will soon be picking up the Pro-Zinger line as well. They also manufacture alluminum landing gears for many of the large manufactures as well as walk in customers and they have recently started carrying Carbon fiber landing gears and tail wheel gears. Nice group to work with, standard internet pricing. They tent to cater to large scale.

Jim

Iflyrc4fun

My Feedback: (132)

Since I started this thread way back when I have tried a few other props. The prop we found to have the most vertical pull on my ZDZ40 was a Meijklic 21 X 8 carbon fiber. Held the rps to around 6900 and pulled the best of all the props we tried.

Jim

krayzc-RCU

My Feedback: (31)

how is the weight of the can compared to the pitts type of muffler does the total weight in the set up increase or decrease? is the 21 x 8 still the best all have seen?

xp8103

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Wow... This thread is still alive.... I;ll chime in. I test ran my ZDZ40 last saturday. Put about one tank full of pump 91 mixed 40:1 with husquvarna XP premium 2C oil. Supersonic wrap around. Fuchs 20x10 cf. With the HSNV set to 1.5 turns per instructions, I was getting a steady 6700. I could get a reliable idle down around 1450. I figger once she's broken in and properly adjusted, I should be in the 6800-6900 range.
I also have a Fuchs 19x10 3-blade I want to try. Also, a bunch have tried 22 inch props. What about a 19 inch prop? 19x10?

rmh

These engines take quite a bit of running till they come up to best performance -
But - my current 40 -a RE- is a real performer - I get 7000+on a Mejzlic 3 blade 19x11 N.
Big props are it's long suite - I cut down 22x10 and 22x12 props -to get a stiff blade --typically around 20"long- tho these don't rev really high - they pull very hard -from low speeds -
From new to broken in -you get , typically a feww hundred rpm increase - depending on prop -a prop that turns 7000 on a brand new engine will turn up more rpm than a prop which started turning 6000 when new.
Best performance is on large cans /tuned pipes - which makes sense .
Early design, industrial conversion engines, typically don't respond this much to really improved exhausts but these engines do -
I am not talking about engines setup for racing - just engines running in the 600-7000 rpm range.
The new 50 engines with really huge porting -can really be made to pull.
Expect fuel consumption to go up tho --fast!

krayzc-RCU

My Feedback: (31)

dick is the newer zdz40 running stonger than the old one? is the can set up right out of the box or does it require a certain header length?

TOMAPOWA

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Ah! Now that I found a thread that contains mostly ZDZ40 users,... I wanted to ask a question if I could.

I have recently purchased a ZDZ 40. I ran it once and it appeared to run fine (turning 20x8 Bambula at 6900). Although it ran great, I noticed that after the running (a long amazing 40 minute run), I noticed that if I was to turn the prop clockwise, I would hear a clunk (metal to metal sound) from the rotary valve/crab area. Actually, if you fully open both carb and choke, you'd hear it louder. In fact, what this sound turns out to be is the rotary valve plate getting "sucked in" towards the crakshaft due to the suction produced by the upstroke of the piston (since at same time, the valve is closed). I would think that this "suction" would in fact pull the valve plate forward but,... should I hear all this noise? Maybe the valve plate has loosened? Has any other ZDZ40 user experienced this "clunking" sound ?? I also hear it when quickly transitioning from high throttle to low. I don't know if I should send it back or not. BTW, RCS says that it probably not a problem. I certainly hope not. I wouldn't want it to die on it's maiden flight, causing my new Giles to become balsa dust. Should I be worried?

xp8103

My Feedback: (16)

Dick,
Glad to hear your experiences on the 3-blade. So I am not off that far with the 19x10 3-blade.
I am getting a 19x10 2-blade mezlik. Perhaps I wont bother drilling it but keep it for another application.

Tomapowa: I'd run it again on the ground first.

rthorne

My Feedback: (29)

Hello Fellas:

I have a ZDZ 40 thats over a year old. I'm in the process of mounting it on a 80" Cap 232. (It was on Sig Sukhoi that went in on the first flight, Sig replaced the plane).

Anyways, how are you guys handling the choke? Any pictures of your setup would be appreciated.

rmh

If you bounce the prop backward on any ZDz single -w/rotary valve - the slap of the rotor is obvious -
It is normal .
I would guess if you succeeded in burning up the engine with NO oil in it- the clearance of this plate may change -but so far - any busted (crash damage) engine I have pulled apart - has the same amount of case (backplate to rotor clearance -.and they all do the little clunk noise.
The choke lever I use for the 40 is always the same - a rod - angles to the right upper side of the cowl/firewall intersection - using a ball link. -- with this - I just slide the ignition ON switch and the choke is right there to pull-
Handy - the rod just rides in a little groove -and the cowl keeps it there.

krayzc-RCU

My Feedback: (31)

on my engines i take a dremil tool and nip off the plate on top of the choke bolt and install a steering arm like the ones used on the tri wheel of a trainer i then run a nyrod to a servo and hook it up that way. hope that make sense. i can post a pic of this type of set up soon.

rcflyerdave

I have a ZDZ 40 on a Stinger 120(about 15 lbs.) and tried quite a few props of all brands and sizes.The Bambula 22-8 turns a few hundred less rpm on the ground but it sure helped to pull noticably better out of hanging on the propl.I really like its performance and price.The ZDZ 40 and 60 takes about 4 gallons till it reaches its full potential if you break it in correctly.My flying buddy and I have had about 8 RCS/ZDZ 1.20 to 120 cc 's and we love the engines and the RCS support is first rate. BTY,the Bambula 24- 8 works great on the ZDZ 60. Dave Childress

rmh

Bambula 22x8 --is THE best match for this engine we have found.
We ran a day of flight tests last fall--using a well broken in engine - on a 13.5 lb Cap. (Pitts type in cowl muffler from RCS-older one.
The object was to find the prop that overall worked the best for flying the IMAC sequences - this one was the best.
On a strictly" what compared" basis --the Zinger Pro 22x10 was very similar -performance wise.
On my Petrel -11 lbs and a tuned can- the prop is still fine - but the 3 blade Mejzlic 19x11 was quieter-also please, note!!it cannot be correctly attached to the engine .
Don't try it unless you can make an adapter to bolt it properly

FalconWings10

My Feedback: (4)

Good thread.

WreckRman2

My Feedback: (5)

Have you tried a Mejzlik 19x10? Much faster spool times which is great for pulling out fast... just stay off the full throttle button unless you need it.

Let's be honest here, we're all testing and rating props at full throttle but how many times during your flight will you be at that full throttle setting? With a 19 over a 20 it'll get to top speed quicker and that could mean getting out of trouble faster. The only way your gonna turn too many rpms and hurt the engine is if you leave it at full throttle for a long period of time, something 95% of us never do anyway...

That's what I'll be using on my 27% CA Extra 300L w/ BME44... a Mejzlik 19x10.

rmh

good prop -but pretty small for the ZDZ to produce best power -- I did try the Mejzlic 19x11 three blade - which turns over 7000 and works very well - a bit pricy tho --

krayzc-RCU

My Feedback: (31)

does zdz still want users 2 run better than 97 octane gas?

Iflyrc4fun

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My new 50 and 80 engine manuals both say to run hi octane fuel so I guess the answer to your question is YES.

TOMAPOWA

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Hey IFLYRC4FUN,
I noticed you had a pic of a Dave Patrick Extra 330L. Did you happen to put a ZDZ in this? Reason I ask is because I am planning to put my ZDZ40 into my DPExtra330L. If in fact yout Extra uses a ZDZ, I would like to hear how it all works together and how the install went. I am still a bit worried about vibration,.. the DPM is built very very light... sort of like a kite! I rattled three CA hinges loose on my 1/4 scale Giles (powered by the same ZDZ40).
Thanks in advance for any info...

krayzc-RCU

My Feedback: (31)

i am running a brison 3.2 on my extra and it shakes at low rpms (1100-1600) I have ca hinges on the entire plane all has been well up to this point.....

TOMAPOWA

My Feedback: (1)

Thanks krayzc,
In any case, I'm planning to use HD Dubro nylon hinges with a continous pin/rod vice cotter pins. I was also going to mount the ZDZ40 using rubber isoltaed mounts but most tell me to hard-mount. Any preferences? I was spinning a 20x10 Bambula on my ZDZ40 and got around 6700rpm max. It only has about 2 gallons run through too so it can only get better. I plan to use a Zinger 20x8 for the Extra. Don't want it to scream across the sky.... some say that the Extra also can have flutter issues... I'll try to avoid it at all costs (i.e. nylon hinges, isolation mounts, lower pitch prop, etc...) I've been following a few RCU threads on the DPExtra w/ ZDZ40 but there has not been too much feedback lately.
Thanks again!