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ZDZ 40 , what props are you using?

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Old 05-02-2003, 12:08 PM
  #76
Iflyrc4fun
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Default ZDZ 40 , what props are you using?

Tomapowa,

Yes, my DP 330 Extra has a ZDZ in it for power. Originally I had the 40 RV in it which flew the plane very well but pulled out of hovers slowly. We played with different props and for our purposes found the Mejzlik 21 X 8 to work best. I now have a
50 RV in the plane and I am much happier with the thrust. Vertical pull out is now powerfull and instantanius with a Mejzlik 22 X 10.
Both engines were/are hard mounted and the airframe is showing no signs of failure. Like you said, I am running the large Du-bro pinned hinges. In addition hinge gaps are sealed and we are running single Airtronics 200 oz in servos and have never seen any flutter even on fast downlines. My plane is one of the original first batch and so it is a little heavier than the current planes and maybe that is why the 50 works better for me. If the 40 isn't enough for you the 50 is a direct bolt in replacement with just a little extra cowl cutting to clear the larger pitts and cylinder head. My engine is mounted hard to the firewall and I cut a hole through the firewall for the carb to fit through. I installed a slide out firewall in the box at F1 to keep engine fuel spitt out of the fuselage. The firewall is pinned and braced with tri stock then glassed over the outside corners. I also added tri stock to the engine box sides and bottom at F1 & F2. Two 1 1/2" holes in the bottom of the engine box allow ample air for the engine to breathe.
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Old 05-02-2003, 12:19 PM
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Default ZDZ 40 , what props are you using?

I checked out an identical setup last week - (ZDZ50)
It 0--on Bambula 20x10 is demonstrably stronger than the 40's
We double checked -same prop -same time - the ZDZ50 vs th 40
The 40 -on a pipe -the 50 on a Bisson Pitts.
The 50 still beat the 40 by 100 rpm --
Iwas surprised as the 40 eats all of the other 40s on the market easily
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Old 06-21-2003, 03:14 AM
  #78
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Default ZDZ 40 , what props are you using?

i have my ZDZ 40 all mounted up the Funtana with a bambula 20 x 10. Big day is tomorrow. How's everyone else ZDZ treating them. My funtana is 12.5 lbs......
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Old 06-21-2003, 03:15 AM
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Default ZDZ 40 , what props are you using?

does anyone know the fuel consumtion at a certain RPM for the 40?
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Old 06-21-2003, 11:33 PM
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Default ZDZ 40 , what props are you using?

HELLO ALL,HAS ANYBODY DONE THIS BEFORE?THIS MORNING I WAS SETTING THE NEEDLES ON MY ZDZ 40.I HAD TO TAKE THE COWL OFF AND TAKE THE PROP OFF.IT TOOK ME ABOUT ONE HOUR TO GET THE BOLTS TO LINE UP ON THE PROP.I COULD GET 5 LINED UP BUT NOT THE 6 TH ONE.SO I LEFT IT OFF TO RUN THE ENGINE FOR A LITTLE WHILE.WELL THE NEXT THING I KNEW THE BOLTS WERE SLINGING OUT AND SHEARING OFF.IT MADE ME SICK.THREE ARE BROKE OFF IN THE HUB.I GUESS I WILL HAVE TO SEND THE ENGINE TO RCS TO PUT ANOTHER HUB ON.ANT COMMENTS ABOUT MY SITUATION WOULD HELP ME AS THIS IS MY FIRST GAS ENGINE.BTY,ZDZ 40 RUNS GREAT THANKS..GREG
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Old 06-22-2003, 04:54 AM
  #81
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Default ZDZ 40 , what props are you using?

the z performed flawless for me today. talk about easy starting wow! i am gettting 6300 on my 20 x 10 up from the 1st tank of 6000. i'm running a brison custom muffler. i love the pull of the bambula on the funtana...
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Old 06-24-2003, 09:33 AM
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Default ZDZ 40 , what props are you using?

Do yourself a favor and buy prop drill jig, it makes drilling props very easy and the bolts line up perfectly. Also make sure you tighten them pretty good and periodically check and retighten them as the wood compresses.

Quote:
Originally posted by GregMac
HELLO ALL,HAS ANYBODY DONE THIS BEFORE?THIS MORNING I WAS SETTING THE NEEDLES ON MY ZDZ 40.I HAD TO TAKE THE COWL OFF AND TAKE THE PROP OFF.IT TOOK ME ABOUT ONE HOUR TO GET THE BOLTS TO LINE UP ON THE PROP.I COULD GET 5 LINED UP BUT NOT THE 6 TH ONE.SO I LEFT IT OFF TO RUN THE ENGINE FOR A LITTLE WHILE.WELL THE NEXT THING I KNEW THE BOLTS WERE SLINGING OUT AND SHEARING OFF.IT MADE ME SICK.THREE ARE BROKE OFF IN THE HUB.I GUESS I WILL HAVE TO SEND THE ENGINE TO RCS TO PUT ANOTHER HUB ON.ANT COMMENTS ABOUT MY SITUATION WOULD HELP ME AS THIS IS MY FIRST GAS ENGINE.BTY,ZDZ 40 RUNS GREAT THANKS..GREG
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Old 06-24-2003, 09:51 AM
  #83
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Default ZDZ 40 , what props are you using?

My zdz40 which is installed in an 80" 13 lbs cap that I'm holding in my avatar turns MenzS 20x10 just a bit under 7000. I also tried MenzS 22x8 and got 6200-6300 the first time I run the engine. Now I get more but havent had the third hand to measure the rpms. I know it has to be more because I measured it before leaning out and it turned 6250.

I recently busted 20x10 and I'm too lazy to drive 200 miles to buy some more, after that I had 2 flights with 22x8. Problem is the engine is not broken in yet (less than a gallon of fuel) and I was told to use 22x8 after break in. How much harm am I doing by using 22x8 ? Im flying it without a cowl to minimize the chance of overheating and have easy access to the needles.
The exhaust I use is KS tuned can with 12" header.
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Old 06-24-2003, 10:11 AM
  #84
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Default ZDZ 40 , what props are you using?

we use very similar setups and the22x8 MenzS runs typically at 6800 rpm so the load is a bit more -
adjust high needle such that engine never appears to drop rpm in long verticals - do not adjust to absolute max on ground - this adjustment varies with engine and airframe combination.
The exhaust setup we used has a longer header than you mention. it is 22" from engine to reflector in can
the can is a different design than th KS- best KS we tried is the least expensive front in -rear out version it runs good at 12-13" header.
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Old 06-24-2003, 10:29 AM
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Default ZDZ 40 , what props are you using?

I use front in front out KS can and I made 12" header per your advice. It was a difficult task to make that header and 12" was all I could do to keep it under cowl. At the end I had to cut the cowl and now header protrudes about 1/4".
Sometimes I wish I bought front in rear out can but then it wouldn't look so cool with exhaust coming out from behind the wing.

How much harm I do using 22x8 during first gallon? When I started with 22x8 I set the needle so I had noticable rpm drop on the ground, when I took off I realized it was way too rich in level flight and too rich in vertical, with this setting it turned 6250 on the ground. I landed, leaned some and it was still too rich up there. Before the second flight I leaned it some more and then it began to produce some real power, I wasn't in the mood to make any more rpm readings so I'm not sure how much it turned.

I only had 2 flights with this prop and plan to have a few more before the weekend when I will probably switch back to 20x10.


Do you think I should make header longer or leave it as it is?

If you remember a month or so ago I reported trouble with shuting down the engine using only throttle, I was able to fix it last weekend by loosening throttle plate and positioning it so that the gap between plate and venturi is minimal.


Quote:
Originally posted by dick Hanson
we use very similar setups and the22x8 MenzS runs typically at 6800 rpm so the load is a bit more -
adjust high needle such that engine never appears to drop rpm in long verticals - do not adjust to absolute max on ground - this adjustment varies with engine and airframe combination.
The exhaust setup we used has a longer header than you mention. it is 22" from engine to reflector in can
the can is a different design than th KS- best KS we tried is the least expensive front in -rear out version it runs good at 12-13" header.
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Old 06-24-2003, 12:28 PM
  #86
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Default ZDZ 40 , what props are you using?

it sounds like you are doing all of the correct things
example -start from rich cool running setup and work to smooth running.
The header length is really related to engine load and so - the rpm it will run decides that .
bigger prop=longer tube.
if the engine changes from low to high rpm with no strange low to mid rpm problem - then it is about right length.
Typically the needle needs to be a bit rich on low needle for best hover and quick power additions--
BUT! in smooth level flying - a bit leaner on low needle, for smoothest power up changes .
listen carefully and note the differences.
you should also have high needle so that full power is best on climbing - NOT on level flying.
all of these adjustments are usually in a 1/4 turn approximate range.
from what you say - the engine/pipe may be about correct with 20x10 or perhaps a slightly shortened 22x8 , with the tips a little smoothed .
I have best performance on props which are slightly shorter and wider and very stiff.
Some I cut down and reshape from next larger sizes .
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Old 08-10-2003, 05:21 AM
  #87
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Default ZDZ40 RVL

I bought my DP Extra with the setup in this picture. It was running a 20 x 10 zinger prop on it until a bad landing today. typical RPM is around 6150. Performance seems lacking to me. What might I expect by going to a Zinger Pro 22 x 10?

PS I borowed the photo from lovemyedge. It is nearly identical to the setup in my extra.
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Old 08-10-2003, 01:25 PM
  #88
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Default ZDZ 40 , what props are you using?

Zinger Pro 22x10 is about same load as 22x8 in menxzS
we did a lot of test flying on ZDZ40 with in cowl muffler (original Pitts type sold by RCS) and that was the best overall performance on a 14 lb H9 Cap (72" span )
the rpm was -I think-- in mid 6000 range - do not remember exact - but the prop worked well
The Diablotin muffler runs about the same --
the 22x8 ZingerPro just revved -was noisy and performance was not as good
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Old 04-28-2017, 06:47 AM
  #89
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Default help me

I purchased an Xroar? 20x8 for this engine.
the hub of the prop is to small and a couple of the bolts would basically just grove the side of the hub

seriously WHere can I get a prop with a hub big enough for this engine?

thanks
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