Spats
100cc
I seem to get the same questions often on switching to ZDZ.
How hard is it to install with a rear carb?
Do you use a choke servo?
Is the bolt pattern the same?
How do you adjust the carb?
So I thought I would throw up a quick overview of what's involved. It's easier than most think.
This is a very old Extra that is made up of about 5 different planes and had as many different engines on it. It’s probably got two pounds of added epoxy and wood. It’s on its third gear and been in the pond at Nall once. It has been sitting in my shop for a couple months waiting for an engine that was sent off for repair. I got tired of waiting so it’s time to put some real power in it and throw it around again.
The bolt pattern on the ZDZ180 is the same as GP, DA and most others so it will bolt straight up.
It requires the same stand offs as the GP I pulled out of the plane.
There is no two ways about it, if you want to be able to adjust the carb with the cowl on you will need to drill a hole in the top of the cowl. In my Extra 300 I did not drill a hole. Usually when I get my carbs set I never mess with it again so no need for a hole.
Get yourself a cheap servo. It will make the set up clean and life easier at the field. Flipping the switch for choke on is so nice. I have seen several different crazy pushrods for chokes on ZDZ’s and it always bugs me to see the pushrod sticking out the side of the fuse. I also have heard about the choke falling on while in flight and killing the engine.
The throttle servo will last longer on a ZDZ I think because it is inside the fuse and away from the major part of the heat. (that's just my opinion). Having the carb inside the fuse also helps eliminate change in pressure causing the engine usually to richen up and run sluggish on midrange.
The first thing is to draw a template for the carb cut out and line up the mounting holes to trace onto the firewall.
I like to use little wood servo mounts from JTEC. They are cheap, light and easy to mount. Someday hopefully I’ll have my own laser cutter to fabricate these fun little things. I don’t like changing the choke arms on the carb so I mount the servo in an angle so the servo arm is the exact same angle as the carb. This way there is no binding on the ball joints and pushrod. For the throttle servo I get it as close to the carb as possible. This helps to eliminate any flex on the pushrod and vibration making the throttle response smooth and efficient.
I set both needles at 1 ½ turns open to begin with. Usually a couple small 1/16 turns in is all I need to get smooth transition and maximum top end. I find my high RPM top end and then back it out (open/richer) a 1/16. Most of the time when I help someone set their engine they have the low needle to lean. I back it out until I get the burble and then ever so slightly turn it in until it’s gone and leave it alone.
Props; Every plane and the conditions you fly in are different so depending on what you want out of the plane will dictate what prop you end up using. I am a bit different than most pilots. On all my 40% planes no matter what engine is on it I use the 3W 3D prop. I do not look for the highest RPM or try to rip the prop all the time. I like this prop for my flying style. It puts wind over the plane where I want it at low and mid speeds. On the ZDZ 180 it will rip it on top end but I do not open it up often or for very long. Nothing is more annoying sounding than a ripping prop screaming across the sky.
This install took me about 4 hours from start to finish, even programming the choke servo. I will try and get someone to take some video this week of it with the new powerhouse.
I hope this helps anyone thinking about stepping up to the new ZDZ 180.
How hard is it to install with a rear carb?
Do you use a choke servo?
Is the bolt pattern the same?
How do you adjust the carb?
So I thought I would throw up a quick overview of what's involved. It's easier than most think.
This is a very old Extra that is made up of about 5 different planes and had as many different engines on it. It’s probably got two pounds of added epoxy and wood. It’s on its third gear and been in the pond at Nall once. It has been sitting in my shop for a couple months waiting for an engine that was sent off for repair. I got tired of waiting so it’s time to put some real power in it and throw it around again.
The bolt pattern on the ZDZ180 is the same as GP, DA and most others so it will bolt straight up.
It requires the same stand offs as the GP I pulled out of the plane.
There is no two ways about it, if you want to be able to adjust the carb with the cowl on you will need to drill a hole in the top of the cowl. In my Extra 300 I did not drill a hole. Usually when I get my carbs set I never mess with it again so no need for a hole.
Get yourself a cheap servo. It will make the set up clean and life easier at the field. Flipping the switch for choke on is so nice. I have seen several different crazy pushrods for chokes on ZDZ’s and it always bugs me to see the pushrod sticking out the side of the fuse. I also have heard about the choke falling on while in flight and killing the engine.
The throttle servo will last longer on a ZDZ I think because it is inside the fuse and away from the major part of the heat. (that's just my opinion). Having the carb inside the fuse also helps eliminate change in pressure causing the engine usually to richen up and run sluggish on midrange.
The first thing is to draw a template for the carb cut out and line up the mounting holes to trace onto the firewall.
I like to use little wood servo mounts from JTEC. They are cheap, light and easy to mount. Someday hopefully I’ll have my own laser cutter to fabricate these fun little things. I don’t like changing the choke arms on the carb so I mount the servo in an angle so the servo arm is the exact same angle as the carb. This way there is no binding on the ball joints and pushrod. For the throttle servo I get it as close to the carb as possible. This helps to eliminate any flex on the pushrod and vibration making the throttle response smooth and efficient.
I set both needles at 1 ½ turns open to begin with. Usually a couple small 1/16 turns in is all I need to get smooth transition and maximum top end. I find my high RPM top end and then back it out (open/richer) a 1/16. Most of the time when I help someone set their engine they have the low needle to lean. I back it out until I get the burble and then ever so slightly turn it in until it’s gone and leave it alone.
Props; Every plane and the conditions you fly in are different so depending on what you want out of the plane will dictate what prop you end up using. I am a bit different than most pilots. On all my 40% planes no matter what engine is on it I use the 3W 3D prop. I do not look for the highest RPM or try to rip the prop all the time. I like this prop for my flying style. It puts wind over the plane where I want it at low and mid speeds. On the ZDZ 180 it will rip it on top end but I do not open it up often or for very long. Nothing is more annoying sounding than a ripping prop screaming across the sky.
This install took me about 4 hours from start to finish, even programming the choke servo. I will try and get someone to take some video this week of it with the new powerhouse.
I hope this helps anyone thinking about stepping up to the new ZDZ 180.
I'll buy 10 right now
I have two builds coming up with ZDZ's and this would just be to cool to do.
