I am currently building one of these and need help in two areas.

#1: the firewall is marked with a cross hairs for engine alignment right in the center of the firewall. What would it do to the flight characteristics if I were to invert the engine and move it towards the top of the firewall? I would benefit from increased ground clearance for both the head and the prop. Is this a tragic mistake?

#2: I am trying to decide on which engine to use on the plane.

wingspan:67"
wingarea:1120"^2
OAL:64"
weight RTF: 9-10.5 lbs

RCS 1.40 2lbs w/ign 3hp
MVVS 1.60 2.1lbs w/ign 3-3.8hp
RCS 1.80 3.15lbs w/ign 4hp
ZDZ 2.40 3.15lbs w/ign 4.8hp

So far people think that the 1.40 may be too small for unlimited vert and many believe that the ZDZ 2.40(40) is too big. The 1.80 is said to be the best choice. What I don't get is why is it better when it weighs the same as the zdz 40. So why not put the 40 on and meter your throttle. I imagine that I just don't have the practical experience that I need to see the obvious. I hope that someone will explain it to me.

thanks,
LeRoy

bump

I just started one for a flyin Bud and the fire wall is only 3 11/16" wide and 4 3/8" tall.
This is the practical mounting area , are any of these gassers gonna fit?
The plan for this one is a Saito 1.80 and it's going to be upright to fit without some chopping.

What kind of mounting foot print do these have ? thats what I'd look at first.




Den

Welcome Powaw: I see no reason you could not use the rcs 1.4. You say the plane should weigh 9+ pounds. RCS claims 15.6 static pounds of thrust using a 16 by 8 prop. This seems to me it would fly the plane fine, depending on how it runs in your neck of the woods, IE air density, ambient temp. humidity, and such. I live at 6000' so I would be tempted to go for more power, (grunting) yes I am a big fan of tool time. (grunting again). Thus I would go for the biggest thing I could stick in there. Hey I just had an idea for that old Volkswagen I have in storage, and the Herr 1/2A Piper Cherokee that needs, you guessed it more power.

I have already been investigating the footprint. They will all bolt up. The problem lies in the small size of the fuselage. On the zdz about 2.5 inches will hang from the bottom. About 2 inches on the 1.80. The 1.60 has a little under 2inches hanging. I don't think that I will consider the 1.40 any longer and am leaning heavily towards the 1.60 with the tuned pipe. Here is what the weight to hp ratios are for each engine w/ign assuming that the plane weighed 8lbs before you installed the engine.

rcs 1.40 unknown muf. 53oz/hp
mvvs 1.60 normal muf. 54.3oz/hp
tuned muf. 42.9oz/hp
rcs 1.80re unknown muf. 45 oz/hp
rcs 1.80rv unknown muf. 44.6oz/hp
zdz 40 unknown muf. 37.2 oz/hp

I would assume that the unknow mufflers were actually tuned pipes. Would make sense to me anyway. A rough calculation shows that the mvvs 160 would have to up its hp output to 4.38hp to equal the zdz40's 37.2 oz/hp.

The zdz would probably be able to haul more passengers, but I think that the mvvs equiped plane maybe more responsive and fun to fly since it will be a pound lighter to begin with. I would think that the mvvs would also have unlimited vert also. What are you opinions?

LeRoy

Hey Leroy: I tend to go to power. But if it means sacrificing weight? I'M SO CONFUSED Actually I am thinking of the RCS 1.4 on the Goldberg Super Chipmunk. I know it is a 60 size plane, but I am pretty sure it will bolt in, and I think I can move all the radio equipment back to compensate for the extra weight, unless the servos and such mount way back anyway. Since it is going to be an inverted installation I don't mind if some of the head sticks out the bottom. Not sure though, I need to do a lot more research, and I'm counting on some feedback from here as well. I'm pretty set on the 1.4, I've read nothing but good about them. But I must admit the ZDZ 40 looks pretty tasty as well, what, with all that's included, prop and drill jig, battery and charger, ignition, mount, and muffler. I think there is actually more bang for the buck here at $430. But would definitely have to give up on a 60 size plane. Although I did squeeze a Saito 91 into my Tiger 2, a 40 size plane. As for mufflers I would E-mail them to be sure, I won't swear to it but I don't think they come with a tuned pipe. Always glad to help if I can. Garry

I'm with you, just label me confused. Too bad I couldn't just get them all free for thirty days just to try them out. LOL Well gotta see if I can find any more reviews.

Powaw I like the way you think!