snotlocker

My Feedback: (14)

Hey , whats up with my ZDZ 40 ?
Its in a sig soukoi ARF
and with a BAMBULA 22x8 im only getting a lame 5600 out of it , its enough to fly the plane but you guys are getting way more then this ? HUH?
ive got almost a gallon in her , ive had the timing all over the place ,hi test fuel , MAXIMA K2 synth oil , S/W unabtainium muffler ....any ideas ?

ninefingers

My Feedback: (18)

Locker. I'm not an expert but thats kind of a big diameter prop for a 40 cc insnt it?? I just acquired a FPE 2.4 (40 cc) and they recommend a 20 x 10. I'm not sure how much you'll gain though. You're numbers are awful low. ...nine

Vince

My Feedback: (1)

22x8 is too much prop for that engine IMO. I have a Fox 2.4 in the same plane with a 20x10 and I am turning 6800-6900. I realize that you are trying to get enough prop past that enormous cowl, but try a 20" instead

Vince

bpryor

My Feedback: (45)

snotlocker,

A 22X8 on that engine should be just fine. They are designed to pull that size prop....but your RPMs are way down. I found one reference to the BAMBULA being similar in load to a Menz S, so I would expect around 6300-6400RPM, which would be fine, but your numbers are pretty low. I would at least try another prop of known quantity and see what you get on that. It might be just too much prop while you're breaking it in. If you want to run a 22" prop with a bit less load, try the Zinger Pro 22x8. You should see around 6600-6800 RPM with a new motor.

epc

My Feedback: (33)

a 22x8 is a good prop for a good 40cc so it should be ok.

As bpryor said you should break it in with a light 20x10 ( pro zinger or menz ultra) and then switch to a 22x8.

With the 22x8 the engine should turn 6300-6500.

epc

fred685

My Feedback: (67)

Here are some numbers from my 40.
Zinger 20-10 7400
Pro-Zinger 22-10 6000
Zinger 22-12 5800
I am currently using a 22-8 Pro-Zinger and it works nice but I have not tached it yet. The engine has a Bisson muffler and about 1 gallon of fuel run through it. Hope this helps.

Fred

snotlocker

My Feedback: (14)

Well i am way off of the rpms this motor should be getting !!!
even though its not quite broke in yet . it should still spin this 22 X 8 lumber ,
will the 20 X 10 be less drag?
what is harder to spin ? pitch or leanth ?
what are you seeing with a broke in motor ?..lots more RRRRRss ?
compared to a unbroken in motor ?


and last but not least .. any ideas wht else could be wrong?
mechanical?

fred685

My Feedback: (67)

What muffler are using? What type of oil?

snotlocker

My Feedback: (14)

im running a S$W TITAINIUM PIPE / MUFFLER ( PRITTY)
AND MAXIMA K2 SYNTH AT 50 TO 1 NOW ....SUPER UNLEADED

OUTCAST

Snotlocker you should see at least 6200 with a 22/8 and about 6500 with a 20/10. The engine will pick up 3-400 rpm with break-in no more, also ckeck your mixture, they are sensitive for the first couple gallons. I have also found that mine does not like octane over 89, in fact it runs best on 87 about 100 RPM higher. You may also want to check your timing, I don't know what system you have but timing can change a *****cat to a tiger.I have a program that gives horsepower and thrust for any prop /pitch, a 20/10 at 6500 needs 3.1hp, a 22/8 at 6200 heeds the same 3.1hp. The 20/10 at that number will produce about 19 lbs of static thrust and 60 mph, the 22/8 will yeild 25lbs at 47 MPH. Hope this answers some of your questions.

luv2flyrc

My Feedback: (6)

My ZDZ 40 was turning a Mejzlik 20x10 at 7200, Menz S 20x10 at 6100 and a Bolly 21x8 at 7600 rpm , this was with a Bisson Pitts style muffer. I sold the engine with less than 2 gal through it because I was disappointed that the #'s were far below the Moki 2.1 it was replacing. It didn't seem to be the powerhouse that some have reported it to be. In my case the bison muffler may have been too restrictive but i wasn't about to start buying alternate exhaust systems to try to get more performance as that could be more costly than replacing with a more powerful engine.

fred685

My Feedback: (67)

The S&W muffler is probably your problem. I have one but have not tried it yet. They are very quiet but also very restrictive. The Bisson is also restrictive.Take the muffler off and see what kind of numbers you get. I think it will perform the way it should. The best muffler for ZDZ's are a canister type if you have the room, if not try the J&A.

Fred

snotlocker

My Feedback: (14)

Thats a suprise that it might be the s&w muffler ,
it fails the DB sound test , its very loud ,
that would be a big dissapointment also cause i also bought a s&w for my zdz 80 ..


anybody else running a S&W muffler ?

Bob Pastorello

My Feedback: (198)

Well, I wasn't going to wade into this, but here's MY RPM figures. These are WITHOUT Tuned cans, just the Bennet "manifold" (can't call it a muffler) and the J&A Pitts style...I have TWO of these motors; they are nearly identical, except for break in. The broken in version is turning my ProZinger 20 x 10 at 6900 on Pennzoil 40:1 and 87 octane. 85degree day, 65% humidity. My other motor turns the same and it is only a couple gallons fresher.

IMHO - the ZDZ 40 is an excellent VALUE, for the weight, size, and power available. It is VERY difficult to attempt to compare muffled/manifold motors with so many variables in the muffler design. I'd think ANYONE with a ZDZ 40, in good shape, should be able to turn ANY flavor of a 20x10 at 6700 rpm or more. Below that, and something is amiss.

OUTCAST

I agree with aerobob, I'm turning the same 6900 with the pro zinger 20/10 on 87 octane and a bisson, but expect a little less untill it's broken in and adjusted. I have been using Huskavarnia chain saw oil at 40-1 with good results. Aerobob what oil do you use?

Bob Pastorello

My Feedback: (198)

Well, since discovering Redline Racing 2 stroke oil (courtesy Dick Hanson) that is the synthetic I use. Since I'm currently on two relatively-new ZDZ's, I'm using 40:1 Pennzoil 2 cycle Ashless...works fine. I've used Amsoil - it was okay, but NO way I will go beyond 45:1 (meaning definitely NOT 100:1).
When less-experienced I actually used some Stihl chainsaw 2 stroke oil - NASTY stuff...lots of UGLY exhaust residue that couldn't hardly be cleaned off the plane. Lesson learned!!

wingnutII

If you are trying to break the motor in, which it sounds like you are. You are doing almost everything wrong. You maybe getting bad #'s on principle alone. A 22x8 brambula is a rather large hunk of wood similar to a Menz S, which should not be used until after break in. Break in will start in another 50 or so gallons if you are using synthetic oil from the get go.

From the information you have given, it sounds like exhaust restriction, second something is horribly wrong w/fuel/intake/porting/timing. Or operator error.


Try running you engine with out the S&W's on. You should see a huge increase in your numbers.

Kurt

Scorpionjack

http://www.rcuniverse.com/showthread...7&pagenumber=2]

Diablo-RCU

My Feedback: (1)

I think Fred has it right, it's the muffler. My buddy HT's would turn a Mejzlik 20x10 at 7600 rpm. He was using the B&B (muffler?). Too much backpressure in the muffler delays the mixture flowing through the transfer ports. Get some earplugs, and test it without a muffler....I think the power will return.

cygnet

My Feedback: (33)

Snotlocker your problemis the Bambla prop. The size is okay but the brand is the problem I have a ZDZ 80 twin I tried a Bambla 26x10 on the week end and my engine would only turn it at 5400 switched to a menz and the RPM'S jumped to 6300. I have a buddy with a ZDZ 40 and he turns a Menz S 22X8 at 6300 it takes a 15lb plane out of sight straight up. Sooo just change props and go tear holes in the sky just my .02

Vince

My Feedback: (1)

I tend to agree with cygnet about the prop. I have seen this problem with a Top Flite prop. Switched to a Zinger, and all was well. We could see no visible problem with the Top Flite prop, but it would only give 5500rpm on a G62.

Vince

Scorpionjack

Cygnet;
The Bambula Prop isn't the problem! I have the same engine turning a 20 X 10 Bambula 7100 Rpm look at the link above and you can see the tach readings.

OUTCAST

Well pop, to find out if its the prop, switch it with a Zinger pro, and let us all know.
Hey did you like that it rhymed!

snotlocker

My Feedback: (14)

I TOOK MY 22x8 BAMBULA OVER TO A BUDDYS HOUSE AND STUCK IT ON HIS DP EXTRA W/ZDZ 40 ON IT ,
IT WAS DOGGING HIS MOTOR ALSO !!!! 5900 rpms
AND HIS zdz 40 IS BROKEN IN !!!
WOW THATS A PIECE OF LUMBER !!! :stupid:

Shawnben

I have a new ZDZ 60 with 2 Gallons of gas through it. I have a Zinger 24x10 cut down to 22" and I'm turning 6400 rpms. it will turn 6600 but I'm running it rich till it breaks in.