World Models .60 Zero - Engine mounting problem
 

I just purchased the World Models Zero .60 sized model. How do you get a standard .61 2-stroke glow motor to sit in the mounting area and mount the muffler. The large round mounting area prevents the muffler from mounting on to the engine. I don't want to buy a pitts muffler. Any adapters to allow the muffler to extend out at an angle?

RE: World Models .60 Zero - Engine mounting problem
 

basil- what engine do you have? have you contacted the place where you bought it to ask them about this?

Ed

RE: World Models .60 Zero - Engine mounting problem
 

Basil,

There is no cutout for the standard muffler to pass through. If you want to use a standard muffler, you'll have to mount your engine the way you want it, and cut away the firewall in the area where it will pass through. Then build a passage for the muffler and exhaust to pass through.

I just bought the Pitts muffler. With a .61 twostroke on the front, it took something like 13 oz of weight (screwed to the mounting box) to make it balance. The .61 flies it well, but you might want to use something larger, to cut down on the weight you'll need to add.

The retracts are nice, but take them out, and hack out the rails so you can tilt the gear forward. Otherwise it will nose over on landing. Unless you fly off a hard surface, you'll want to replace the easliy bent gear.

Oh, and use the lower end of the elevator travel, or lots of expo. This plane flies well, but is very sensitive in pitch, even when balanced correctly.

Good luck,
Dave Olson

RE: World Models .60 Zero - Engine mounting problem
 

Scar,
I have this arf too. I was planning on mounting a Supertigre G90. This engine weighs 25 oz with a slimline pitts muffler. What 60 size engine did you use? I know the O.S. 90 and 60 size engines only weigh about an ounce or two less than the G-90. I was hoping that the G-90 would weigh enough not to need alot of lead in the nose. I am also doing a lot of "remodeling" of this arf to try to reduce the need for added nose weight. I have ripped out most of the wood structure aft of the wing inside the fuse. So far I have removed about 4 oz of weight behind the c.g. Based on your post, this could result in not needing 8 of those extra 13oz's that you added to the nose of your Zero. The fiberglass fuse seems to be strong enough by itself with the longerons only. I feel confident in doing this because my Great Planes GeeBee R-2 has far less wood structure in it than does the WM Zero.

Basil,
Here is another solution to your problem of a muffler that is too long. I don't know were to get the parts to do what is pictured, but it looks like the parts are simple enough to fabricate yourself, Yousif.:) For example, you could just cut the bottom off an alluminum pop can, drill a hole the same size as the outlet of your stock muffler and JB Weld it on. You would probably also want to JB Weld on an outlet tube that vents the exhaust outside the cowel. Just keep the diameter of the tube the same as the stock muffler outlet to be sure to maintain proper back-pressure. (note : the muffler in the picture was shortened so that it could be mounted backwards for a pusher configuration) I found this picture in the PDF manual for a "Lightning Dart (B2)" flying wing at the AK-Models web site.

RE: World Models .60 Zero - Engine mounting problem
 

I just bought a RJL .61 for the plane at a close out sale for $70 (hobby shop closing price). This is supposed to be a good engine but the muffler is really long. I don't know why World didn't make the wing loading a little larger and give the option of a four stroke. I have a TT .91 that is fully broken in that I thought I coould put in but that would be a disaster at 25oz of motor. At this point if I can get a pitts muffler for the RJL .61 I would get one. Seems like a muffler inside the cabin is risky. Has anyone flown it with the TT.91

For the retracts I bought the Hobbico thick mechanical retracts with the metal mountings. These look like they are a cheaper option to air retracts.
Does the wing need to be reinforced on the under the retract area with epoxy and fiberglass netting.

RE: World Models .60 Zero - Engine mounting problem
 

Basil,
You don't select an engine for a plane based on the manufactuers wing loading estimate. You select an engine for a plane based on how much weight it takes in the nose to make the plane balance at the recomended C.G. According to Scar's post, even your 25 oz TT .91 engine may not be heavy enough to balance the plane properly and you may still have to add some lead to the nose. You can estimate how heavy an engine it will take to ballance your plane by assembling the main assemblies of the plane (tape things together if you havn't glued the parts together already). Put the servos and battery as far forward as possible (the instructions suggest putting the battery under the fuel tank). Leave the cowel off and secure a long dowel in the firewall hole. A half gallon of water weighs 4 lbs so fill up a half gallon plastic milk jug till the plane balances when you hang it off the dowel next to the firewall. My tests suggest that a 25oz engine is not heavy enough. That is why I removed the wood structures behind the wing.

RE: World Models .60 Zero - Engine mounting problem
 

double post

RE: World Models .60 Zero - Engine mounting problem
 

People have flown this plane with .91, 1.00, and 1.10 four strokes without much issue. I don't foresee any problem in mounting a .91 four stroke.

RE: World Models .60 Zero - Engine mounting problem
 

That sounds great I'll use the TT .91 I originally intended to put in to the plane. In the specs they don't list any four stroke engines for the plane so I thought that you couldn't put one in. If the 25oz of wheight works that's the way to go. And it will sound like a warbird. Does it matter which way I mount the four stroke. Inverted or upright. The nice thing is that even mounted upright the cowell covers most of the head of the engine so it still looks good. The TT .91's muffler can come out at an angle out of the cowell. Isn't this plane hard to land with so much body weight and a small amount of wing area. Do you absolutely need the flaps.

RE: World Models .60 Zero - Engine mounting problem
 

If it's not too much trouble, mount the engine inverted to avoid any unsightly holes at the top and side of the cowl. If the plane is hard to land, use full flaps on landing.

RE: World Models .60 Zero - Engine mounting problem
 

Basil,
I get the feeling that this is your first .60 size warbird. If so, you might want to seach this site for tips on how to handle a warbird. If you've seen any video of Richard L.'s flying, you'll know that he knows how to fly warbirds. Maybe he can direct you to a good article or two. From what I have read and from my own inspection of the plane, the WM Zero should make a very good first .60 size warbird. As far as wing loading goes, you will not be able to find a .60 size warbird with much lighter wingloading than the WM Zero. High wingloading is not the main difficulty with scale warbirds. The main problem with warbirds is the wide fuselages and the lage diameter propellors needed to extend past them. If you flame out, all that frontal area is going to act like an airbrake and slow you down pretty fast.

RE: World Models .60 Zero - Engine mounting problem
 

My Tower .61 Twostroke pulls mine around just fine, big loops, good rolls, etc. Wants to roll out of knife-edge, but that's expected.

Glide path is a lot like a sport plane, chop the throttle as you turn from downwind, it'll slow down when you level out over the apron. Should be ready to land mid-field. Then it will touch down, and (if you're landing on grass) promptly flip over & break the canopy. Unless you've tilted the gear to the front. With retracts, that means changing the mounting angle.

If you rig for flaperons, use very little. Then get used to the pitch-up that follows, or mix out with elevator. If this is your first go-'round you might want to try them out, up high. Then switch them off & land to mix out that pitch-up. Try again, up high, and repeat until you get the pitch change mixed out. I don't use flaperons on mine.

Cheers,
Dave Olson

RE: World Models .60 Zero - Engine mounting problem
 

The second generation WM .60 Zero has flaps, so I would suggest using full flaps on landing to increase stability and lower the landing speed.

RE: World Models .60 Zero - Engine mounting problem
 

Mine has the flaps. I don't have any problems flying P-51's any size but the zero just has a bigger fus and smaller wings than the WM P51 and H9 P51's I have. I'll mount the TT .91 upside down in the zero. I think the last WM Zero (same ARF) I had crashed because the TT .91 was not broken in. It was running badly and that was why the zero came in hot and took the lower part of the plane out. The wings went to pieces under the plane. The flight was very exciting the plane felt like a bus flying through the air. Now I've broken in the TT .91 on a ugly stik so it runs like a top. I should have better luck this time. I think the advise on bending the landing gear forward. Has anyone reinforced the wing under the retracts with fiberglass and epoxy. I usually do this to the cabin area.

Has anyone have any of the Nitro Models Warbirds. There selling at a very good price and I was wondering if they are high quality. I was looking at a Warhawk 1.40 size for $215

RE: World Models .60 Zero - Engine mounting problem
 

How much of the cowl are you guys cutting out for engine cooling?

Also, I fly on a grass field and it sounds like this models retracts cause nose overs? It this true with flaps and lower landing speed?

RE: World Models .60 Zero - Engine mounting problem
 

Guys,
Let me know if any of you who have the version with flaps, ever decide to sell your Zero.
Thanks ! ;)

RE: World Models .60 Zero - Engine mounting problem
 

I cut the front, cowl opening larger. That didn't seem to help much, but cutting a couple of slots in the cowl directly in front of the engine head helped. I've got a Super Tigre G-90 installed. What engine are you installing? There are a couple of versions of cowls too. Are your cowl flaps molded in the open position? If not, cutting them apart and opening them will help. I shortened my cowl by about an inch or so and I cut some slots in the cowl flaps for dummy exhaust pipes for a more scale appearance. An engine baffle helps direct airflow over the engine's cooling fins too. Top Flite manuals on the Tower Hobbies website show how a proper baffle should fit. My baffle may not be close fitting enough to the engine head and that may be why I needed to cut the slots in the front of my cowl.

RE: World Models .60 Zero - Engine mounting problem
 

I've never flown mine with the stock gear, but shimming the gear to angle forward more and maybe adding larger wheels can help alleviate nose over problems. My gear's axle is close to the leading edge of the wing and does not want to nose over.

RE: World Models .60 Zero - Engine mounting problem
 

super tigre 90

RE: World Models .60 Zero - Engine mounting problem
 

Flaps aren't too difficult to add. Mine came with flaps, but I changed them to split flaps.

RE: World Models .60 Zero - Engine mounting problem
 

more pics

RE: World Models .60 Zero - Engine mounting problem
 

It appears that you've got enough exhaust area under the cowl flaps. Have you run the engine yet with your cowl on? Did you reply to this thread because you are having overheating problems? If you are having overheating problems, I think a baffle will help. I mounted mine to the engine mount so I could get it behind the needle valve. If you do the same, just keep it tighter to the engines cooling fins like how the Top Flite warbirds do. I've built the TF 60 size P-47 and that baffle works well.

Also, have you balanced your plane yet? I've read that people have needed 11-13 oz of nose weight, but I didn't see any weights in your pictures.

RE: World Models .60 Zero - Engine mounting problem
 

I have not done the CG yet. But I know it is tail heavy.
I have run the motor without the cowl and am planning how much to cut the cowl. Some people tend to think the cowl needs to be opened up around engine head and extra around pipes on bottom.

RE: World Models .60 Zero - Engine mounting problem
 

Opening up the cowl around the engine head might do the trick, but I've never tried that unless the head is actually too big to fit in the cowl. I don't know how much cutting would be enough. I'd guess that a hole right above the head that is the same size as the head would work.

RE: World Models .60 Zero - Engine mounting problem
 

This plane is designed for a heavy 4-stroke engine and it's strange how they say it takes only a 2-stroke engine. As far as balancing a Thunder Tiger .91 or a YS 110FZ would be perfect at around 38oz. A Evolution .100 2 stroke motor would get close to that and fly this baby like a rocket. This plane sounds better with a 4-stroke though. It sounds like the real thing when you get close to the ground which adds a nice effect that turns heads. I also had some overheating problems I think you need to cut more holes on the bottom. The small opening all the way around the outside back of the cowl doesn't lert air flow good enough in one spot right where the engine is. It vents air around the rear of the cowel in a circular patern. You need to cut some openings around the engine area under the cowel. For nose overs which are inevitable with this plane I reinforced the cowel underside with fiberglass mesh and marine grade epoxy. But on the inside of the cowell so it doesn't look bad. I just hit the underside of the cowel with some black gas proof automotive spray paint when it noses over - usually when I land to the right of the runway in the grassy area.
Mine is still going strong and looking good after 5 years - good plane get's alot of attention at shows.